Technical Level 2_01

2-1

2 Power Transmission System1. Clutch .....................................................................2-2[1] Structure and operation .........................................2-2

(1) Clutch unit .........................................................2-2(2) Clutch operation mechanism .............................2-4(3) Clutch start system ............................................2-6

[2] Checks and maintenance ......................................2-6(1) Pedal stroke check ............................................2-6(2) Pedal allowance check ......................................2-6(3) Check of the pedal and floor plate clearance

when the clutch is disengaged ..........................2-7(4) Clutch start system check .................................2-7(5) Clutch start switch check ...................................2-7(6) Clutch disc .........................................................2-8(7) Clutch fluid air bleeding .....................................2-8

[3] Failure diagnosis ...................................................2-9(1) Engagement defect ...........................................2-9(2) Slipping..............................................................2-9(3) Unsmooth engagement .....................................2-9(4) Sudden forward movement (jumping out) .........2-9(5) Abnormal noise .................................................2-9

2. Manual transmission ..........................................2-10[1] Structure and operation .........................................2-12

(1) Gear change....................................................2-12(2) Gear ratio ........................................................2-13(3) Shift lever ........................................................2-14(4) Transmission operation ...................................2-15(5) Mechanisms for safe driving............................2-21(6) Internal transmission lubrication ......................2-27

[2] Overhaul ..............................................................2-27(1) Important points for disassembly ........................... 2-27(2) Check of internal transmission parts ...............2-27(3) Important points for assembly .........................2-28

[3] Failure diagnosis .................................................2-28(1) Abnormal noise ...............................................2-28(2) Gear engagement and disengagement

problems .........................................................2-29(3) Gear jump out..................................................2-29(4) Oil leaks...........................................................2-29

3. Transfer ................................................................2-30[1] Structure and operation .......................................2-31

(1) Part-time 4WD, separate from the transmission (Jimny: SN413) ..........................2-31

(2) Full-time 4WD (Swift: RS413) .........................2-35(3) Full-time 4WD (Grand Vitara: JB420) ..............2-36(4) Synchro-mechanism........................................2-41

[2] Checks and maintenance ....................................2-43

4. Drive shaft ...........................................................2-44[1] Structure and operation .......................................2-44

(1) Drive shaft .......................................................2-44(2) Constant velocity universal joint ......................2-44

[2] Checks and maintenance ....................................2-45(1) Drive shaft .......................................................2-45(2) Constant velocity universal joint ......................2-46

5. Propeller shaft .....................................................2-47[1] Structure and operation .......................................2-48

(1) Propeller shaft .................................................2-48(2) Center bearing.................................................2-48(3) Universal joint ..................................................2-49

[2] Checks and maintenance ....................................2-49(1) Propeller shaft check .......................................2-49(2) Universal joint check .......................................2-49(3) Important points for propeller shaft

disassembly (Jimny: SN413) ...........................2-50(4) Important points for propeller shaft

assembly (Jimny: SN413) ...............................2-50(5) Important points for center bearing

disassembly (Swift: RS413) ............................2-51(6) Important points for center bearing

assembly (Swift: RS413) .................................2-52

6. Differential ...........................................................2-53[1] Structure and operation .......................................2-54

(1) Differential (rear of FR vehicles and 4WD vehicles) .................................................2-54

(2) Differential in FF vehicles ................................2-56[2] Checks and maintenance ....................................2-56

(1) Backlash check ...............................................2-56(2) Teeth contact check.........................................2-56(3) Differential assembly (Jimny: SN413

(Rear)) .............................................................2-58(4) Failure diagnosis .............................................2-62

2-2 2 Power Transmission System

1. ClutchThe clutch is positioned between the engine and the transmission. It transmits the engine power using the frictional force between the clutch disc and plate, and the force that pushes down these parts. The clutch is made up of an operation mechanism, which transmits the operation force of the driver through wires or hydraulic pressure, and a clutch unit that receives this force and connects and disconnects the power transmission.

[1] Structure and operation(1) Clutch unit1) Clutch unit structureThe clutch unit components include a clutch disc, clutch cover and release bearing.

3002

Clutch disc

Clutch cover

Release bearing

Pressure plate

Diaphragm spring

A diaphragm spring and a pressure plate are assembled to the clutch cover. They are fixed to a

flywheel with bolts.

The clutch disc is installed between the flywheel and clutch cover (pressure plate), and is fitted into

the transmission input shaft and splines.The clutch disc is press fitted between the flywheel

and pressure plate by the spring force of the diaphragm spring.In other words, the engine power is transmitted to the transmission input shaft via the frictional force between the clutch disc, flywheel and pressure plate.

Clutch operating cylinder

Clutch housing

Clutch cover

Clutch master cylinder

3P50

Clutch pedal

Flywheel

Engine

Release fork

Release bearing

Input shaft

Clutch disc

Transmission

2-32 Power Transmission System

Cushion plateThe clutch facing is riveted together while sandwiching a curved cushion plate. When the clutch is connected suddenly, the bending of the cushion plate absorbs the impact, resulting in a smooth power transmission.

3) Diaphragm spring clutch operationWhen the clutch is connected, the spring force of the diaphragm spring pushes the clutch disc strongly against the flywheel via the pressure plate.

This means that the clutch plate rotates together with the flywheel so that the power from the engine

is always transmitted to the transmission.When the driver steps on the clutch pedal to cut off the power, the release fork pushes the release bearing against the end of the diaphragm spring. At this time, the pivot ring (wire ring) becomes

the fulcrum and the diaphragm spring outer circumference bends back. The retracting spring (retainer plate) moves the pressure plate to the

right. Because this creates a gap between the

friction surfaces of the clutch disc, the power from the engine is cut off.

Clutch facing

Rivet

Damper spring

Clutch hub

Clutch disc

Damper spring(absorbs the impact)

3003

Cushion plate

Facing

Rivet

3004

2) Clutch disc structure- Clutch discClutch facing, which is a frictional material, is

riveted to both sides of the clutch disc. There is a clutch hub in the center of the clutch disc into which the transmissions input shaft is inserted.The clutch facing must have an appropriate friction coefficient. Its friction coefficient must not change much with temperature variations.

- Damper springThe clutch hub is sandwiched between plates to its front and rear, and is constructed so that the clutch can move in a circle (rotation direction) via the

damper spring. It absorbs and dampens the rotation impact when the clutch is connected.

Clutch cover

Diaphragm spring

Flywheel

Retracting spring

Clutch disc

Pressure plate

When the clutch is connected

When the clutch is cut off

Clutch cover

Pivot ring

Release bearing

Release fork

End of diaphragm spring

Clutch disc

Pressure plate

3005


(2) Clutch operation mechanism1) Mechanical operation mechanismIn this system, the clutch pedal and release fork are connected with a clutch cable.When the driver steps on the clutch pedal (1), the

clutch cable is pulled (2) (3), and the release fork

pushes the release bearing onto the diaphragm spring (4).

When the driver releases the clutch pedal, the spring force of the return spring and diaphragm spring returns the release fork and clutch pedal to their home positions and power is transmitted to the transmission.

- Master cylinderThe master cylinder is made up of a cylinder section in which a piston slides a long distance, and a reservoir tank that stores the clutch fluid. The master cylinder generates the hydraulic pressure for operating the clutch. To generate the hydraulic pressure, when the driver steps a little on the clutch pedal, the piston is pushed and the clutch fluid inside the cylinder is sent

to the reservoir tank. When the driver steps more on the clutch pedal, the piston moves and releases the connecting rod, which up to now had been pulled by the spring retainer. The spring force of the small conical spring that is built in to the connecting rod moves the inlet valve to the left and cuts off the inlet return common port. At the same time, the fluid pressure inside the cylinder rises rapidly. The clutch fluid is sent

to the operating cylinder and moves the release piston.

3006

Clutch cable

Adjust nut

Clutch pedal

(1)

(2)

(4)

(3)

Release fork

3007

Pipe

Flexible hoseMaster cylinder

Clutch pedal

Release cylinder

Release fork

(1)

(2)

(4)

(3)

When the driver releases the clutch pedal, the piston is returned by the spring force of the return spring and the hydraulic pressure drops. This makes the clutch fluid return from the operating cylinder side. Also, because the spring retainer pulls the connecting rod, the inlet valve opens the inlet return common port. This connects the reservoir tank with the master cylinder, and the master cylinder is filled with clutch fluid.

2) Hydraulic operation mechanismThe components of this system include a clutch pedal, master cylinder, release cylinder, release fork and pipe. The pedal force (1) (2) is transmitted by

hydraulic pressure (3) to the release fork (4).

The hydraulic operation mechanism delivers reliable operation that is light and smooth. However, it has a

complex structure, and if air enters the clutch fluid,

it results in improper operation in the same way as in the brake hydraulic system (becomes difficult to

disengage the clutch). Attention must also be paid

to the clutch fluid level.

Piston

Reservoir tank

Inlet return common port To the operating

cylinder

Spring retainer

Connecting rod

Inlet return common port

Inlet valve

Conical spring

3P43

3P44

Inlet return common port From the operating

cylinder

Spring retainer

Piston

Connecting rod

Inlet return common port

Conical spring

Inlet valve

Reservoir tank


- Principle of leverage The principle of leverage is the way that

a small force changes to a large force depending on the distance ratio between the fulcrum, effort (point of force) and load (point

of operation). This principle of leverage

applies to the clutch pedal, release fork and diaphragm spring.

Also, if the movement distances of the load and effort are l1 and l2, respectively, then:

This means that the long but light movement of the clutch pedal can be used to operate the shor t but heavy movement of the pressure plate.

- Pascals principle When pressure of a certain force per unit

area is applied to one area of a fluid in a sealed container, regardless of its shape, the pressure is transmitted undiminished to all areas of the fluid.

When pressure is applied to a sealed fluid,

force of the same strength (force per unit area) is generated in all parts.

Using this Pascals principle, the force

is increased by making the area of the operating cylinder larger than the master cylinder.

L1

F1

F2

L2

Effort

Fulcrum

Load

3011

Area 20cm2

Force 100N

Area 10cm2

Force 50N

Operating cylinder

Master cylinder

3012

The balanced relationship is:

This means that the force is a multiple of .

- Operating cylinderThe hydraulic pressure generated by the clutch master cylinder acts on the piston. It acts as a force that moves the piston. Also, together with the tension from the piston spring, it operates the clutch via the push rod and the release fork.The bore of the operating cylinder is larger than the bore of the master cylinder, which reduces the pedal force required when operating the clutch.

Piston spring

Push rod

Piston

From the master cylinder


[2] Checks and maintenance(1) Pedal stroke check 1. Measure stroke a of the clutch pedal. If the

value deviates from the standard, loosen the locknut and turn the adjust nut to adjust pedal

stroke a. 2. After adjustment, tighten the locknut to the

specified torque.

Adjust bolt

Locknut

Clutch pedal

a

3013

Clutch pedala

(2) Pedal allowance check 1. Measure distance a, which is the distance

until resistance is felt when the clutch pedal is pushed down.

(3) Clutch start systemThe clutch start system is a safety mechanism in MT vehicles that prevents mistaken start-off when

starting the engine. In this system, if the driver turns the ignition key to the engine start position without stepping on the clutch pedal, the clutch start switch in the engine start circuit does not supply power to the starting motor.

Clutch start switch

Clutch pedal

3P36

M

Main fuse

Ignition switch

Clutch start switch

Starter relay

Magnetic switch

Starting motor

STStarter fuse

3P51

Engine start circuit


2. I f the measured value deviates from the

standard, turn the adjust nut of the clutch cable

on the transmission side to adjust release arm

allowance b.

Clutch cable

Adjust nut

Release arm

3015

b

Clutch pedal

3016

a

3. After adjusting the release arm allowance,

check again allowance a of the clutch pedal, and start the engine to check whether the clutch operates normally.

(3) Checkofthepedalandfloorplate clearance when the clutch is disengaged

1. Start the engine. While the engine is idling, fully

pull up the parking brake lever and place wheel blocks around the tires.

2. S t e p o n t h e c l u t c h p e d a l a n d p u t t h e

transmission into the 1st gear.

3. Slowly release the clutch pedal so that the

vehicle does not start off suddenly. In the position immediately before the clutch engages, measure clearance a between the pedal and the floor plate.

(4) Clutch start system check 1. Check that the c lutch pedal s t roke and

allowance are within the standards, and adjust

them if there are any problems. 2. Check that the starting motor does not operate

when the clutch pedal is not stepped on. 3. Check that the starting motor does operate

when the clutch pedal is fully stepped on. 4. If there is a problem, check the clutch start

switch or perform adjustments.

(5) Clutch start switch check 1. Remove the connector from the clutch start switch.

Check that there is no conduction between the

connector terminals when the clutch pedal is not stepped on. Check that there is conduction between

the terminals when the clutch pedal is stepped on.

Clutch start switch

Clutch pedal not stepped on

Clutch pedal stepped on

Service wire

3P37

2. Measure clearance a between the threaded end

of the clutch switch and the pedal stay. If the value deviates from the standard, adjust by loosening

the locknut and turning the clutch start switch. 3. After adjustment, tighten the locknut to the specified torque.

Pedal stay Clutch start switch

Locknut

Threaded end 3P38

a


(6) Clutch discUse a slide gauge to measure the rivet sink. If the

value is equal to or lower than the limit, replace the clutch disc. Perform the measurements on both

sides of the clutch disc.

3017

Clutch disc

Rivet

Slide gauge

Clutch pedal

Bleeder plug

(7) Clutchfluidairbleeding1) Regular typePerform in the same way as air bleeding for the

brake hydraulic system, but also pay attention to the following.- During the air bleeding operation, make sure that

the fluid level does not drop to half or less.

- After bleeding the air, tighten the bleeder plug to the specified torque.

2) Special type (Swift: RS Series)If the clutch pedal feels soft when you step on it, air may have entered the hydraulic system. Follow the

procedure below to bleed the air.

3. Step on the clutch pedal several times and then

keep stepping down on it. While pushing the clamp, pull out the pipe connector by 1 notch.

When the hydraulic pressure stops, push in the pipe connector. (At this time, the clamp rises and the pipe connector locks.) Repeat this

operation until the air is eliminated from inside the clutch hydraulic system.

Operating cylinder

Operating cylinder

Plastic tube

Bleeder plug

Container

3P01

Clamp

Pipe connector

3P02

4. When the air is eliminated, keep stepping down on the clutch pedal. Push in the pipe connector

and check the locking of the clamp. 5. After finishing the air bleeding operation, step

on the clutch pedal and check that there are no fluid leaks.

6. Fill the reservoir tank with the specified brake

fluid up to the MAX level.

1. Fill the reservoir tank with brake fluid up to the

MAX level (the clutch and brakes share the

same reservoir tank).

(During the air bleeding operation, make sure

that the fluid level does not drop to half or less.)

2. Remove the bleeder plug cap, install one end

of the plastic tube onto the bleeder plug and insert the other end into a container.


(4) Sudden forward movement (jumping out)

Sudden forward movement is a symptom where the vehicle does not start off smoothly. The vehicle may jump forward automatically when the clutch pedal is

operated, or the engine may feel like it will stop.Check carefully whether the cause of the sudden

forward movement is insufficient smoothness in the operation mechanism, or uneven transmission torque caused by a defect in the clutch unit.To perform the check, start the engine, put the transmission into the 1st gear or reverse and slowly

connect the clutch. If the vehicle does not start off suddenly, you can conclude that the clutch unit is in a good condition.

(5) Abnormal noiseContinuous abnormal noise may be caused by

defects in the pilot bearing, release bearing or input bearing, or in bearings inside the transmission. While the vehicle is stopped and the engine is operating, if the abnormal noise stops when you step on the clutch pedal, the defect is probably in a bearing inside the transmission. If the abnormal noise does not stop at this time, the defect is probably in the release bearing or the pilot bearing. Sometimes, a temporary abnormal noise is made during acceleration or deceleration while the clutch is engaged. In such cases, depending on the noise type and the conditions under which it occurs, you must check not only the clutch and transmission, but also parts such as the engine mount and drive belt.

[3] Failure diagnosis(1) Engagement defectTo check for engagement defect, first put the transmission

into the 1st gear while stepping on the clutch pedal. Next,

put the transmission into the neutral position, step on the accelerator pedal to raise the engine rotation speed, and then return the transmission to the 1st gear. At this time,

continue stepping down on the clutch pedal. If an abnormal noise (gear noise) occurs during the above operations, you

can diagnose the problem as engagement defect.In the engagement defect check, you must determine whether the engagement defect occurs because the movement distance of the pressure plate is too short, or whether the engagement defect is caused by a clutch unit problem where the clutch disc cannot separate from the flywheel and pressure plate.

(2) SlippingIf slipping occurs between the clutch disc and pressure plate, it may impair the transmission of power from the engine to the transmission and cause acceleration problems. For this reason, be careful during diagnosis

because this problem is easy to mistake for an engine failure. Check carefully whether the origin of the problem

is in the operation mechanism or the clutch unit.Before performing the check, pull up the parking brake,

place wheel blocks around the tires and fully stop the vehicle. Then, step on the clutch pedal, put the transmission into the 4th gear, and slowly connect the clutch while slowly raising the engine rotation speed. If the engine stops at this time, the clutch is in a good condition. But if the engine does not stop and the vehicle does not

move forward, you can conclude that the clutch is slipping.

(3) Unsmooth engagementCheck carefully whether the cause is insufficient

smoothness in the operation mechanism, or uneven transmission torque caused by a defect in the clutch unit. Check carefully because this may also cause

the engine output to drop or other problems.To perform the check, start the engine, step on the clutch pedal, put the transmission into the 1st gear and slowly connect the clutch. If there is

no uncomfortable vibration at this time, you can conclude that the clutch unit is in a good condition.


2. Manual transmission1) OverviewWhen a vehicle starts off, a large driving force is required even though the engine rotation speed is low. But

when a vehicle is driven at high speed, a high engine rotation speed is required even though the driving force is low. The transmission enables the vehicle to meet these different requirements.A vehicle must also operate smoothly across many different driving conditions. For example, driving at high

speed or slow speed, climbing up or going down hills, repeatedly stopping and starting off, and reversing. The transmission converts engine rotation speed and engine torque in accordance with these driving conditions and transmits them to the drive wheels.

2) FunctionsThe transmission is a gear change mechanism. Its basic purpose is to transmit engine power to the propeller shaft and drive shaft. It has the following functions, which are essential for the operation of the vehicle.

- Power transmissionThe transmission transmits force by meshing gears together.

Main shaft or output shaft

- Reverse rotationA gear is added to change the rotation direction.

- Increasing torque and increasing engine rotation speedThe transmission changes the torque and speed by changing gear combinations to change the gear ratio.

Input shaftOutput shaft

Crankshaft or input shaft

Countershaf t ,

reverse gear

Increasing the force

(engine rotation speed drops)

Changing gears

Speed reduction

A small gear rotates a large gear

Speed increase

A large gear rotates a small gear

Increasing the engine rotation speed

(force drops)

Input shaft

Output shaft

Idle gear


- Power disconnectionThe transmission cuts off the power transmission by disconnecting the gear meshing.


Stop


Input shaft

HubSleeve (3-4)

Main shaft

Shift lever

Each speed change gear

Countershaft Gear

Sleeve (1-2)3019

3020

Countershaft 1st gear

Countershaft 2nd gear

Countershaft 3rd gear

Countershaft 4th gear

Input shaft 5th gearInput shaft 4th gear

Input shaft 3rd gearInput shaft 2nd gear

Reverse idler gear

Input shaft 1st gear

Countershaft 5th gear

(1) Gear change

[1] Structure and operationA vehicle requires a large driving force when starting off, and a high engine rotation speed when driving at high speed.To achieve this, the transmission varies the engine rotation speed and torque by changing the gear combinations (gear ratio).

The engine power is transmitted to the transmission input shaft via the clutch. The rotation of the input shaft is transmitted to the main shaft gear via the countershaft gears. Because the main shaft gear meshes to

the main shaft through the synchro-mechanism that is described later, the rotation from the countershaft is transmitted to the main shaft.In other words, the gear ratio is changed when the sleeve moves in accordance with the shift lever position and changes the gears on the main shaft that connect to the main shaft.When none of the gears on the main shaft mesh with the main shaft, the transmission is in the neutral condition. This means that when the vehicle is stopped and the engine is idling, the engine power rotates the input shaft, countershaft and the gears on the main shaft, but the main shaft does not rotate.


1st , 2nd and 3rd gear - Speed reduction (small

gear rotates a large gear)

4th gear - Direct connection (rotation is transmitted

unchanged)

5th gear - Speed increase (large gear rotates a small gear)

Reverse gear - Reverse rotation (gear is added)Increasing the force (engine rotation speed drops)

Speed reduction

Increasing the engine rotation speed (force drops)

Speed increase

Changing gears

3021

A small gear rotates a large gear

A large gear rotates a small gear

In the time that a large gear with 20 teeth

rotates once, a small gear with 10 teeth rotates

twice. In other words, the small gear rotates at twice the speed of the large gear, but transmits only half the force.

Input shaft Torque

Output shaft

Torque increase

3022

Tire rotation speed is reduced but torque is increased

In this way, the relationship between the transmitted torque and engine rotation speed is determined by the ratio of meshed gear teeth. This means that the torque and the engine rotation speed can be expressed as follows.Engine torque x gear ratio = output shaft torque

(2) Gear ratioThe gear ratio is the ratio between the input gear and output gear rotation speeds. The gear ratio changes as the transmission reduces or increases the engine rotation speed with different gear combinations.

For example, when the engine operates at a

constant torque and a constant speed, if the gear ratio is high (a small gear rotates a large gear), then

a high torque but a low engine rotation speed are transmitted to the tires.But if the gear ratio is low, a low torque and a high

engine rotation speed are transmitted to the tires.


Torque is determined by the size of the force that is applied and the distance from the point of support to the location where the force is applied.This means that when 2 different torque

wrenches, one long and one short, are used to generate the same torque, the longer wrench that is furthest away from the fulcrum requires less force than the shorter wrench.Torque (Nm {kgfcm}) =Applied force x

distance

1) Remote control typeIn remote control type, a rod or cable connects the shift lever to the transmission.This type minimizes vibration and noise because its use of anti-vibration rubber makes it difficult for

engine vibration to be transmitted.


Additional gear

3023

3116

Shift lever

Gear shift control shaft

Gear shift shaft

Joint

Transmission

Fulcrum

3024Rod type

Shift lever

Gear shift control cable

Gear selector control cableTransmission

3115Cable type

Shift lever

Shift fork

3025

Shift fork shaft for 5th and reverse gears

Shift fork shaft for 3rd and 4th gears

Shift fork shaft for 1st and 2nd gears

2) Direct shift typeIn direct shift type, the shift lever is directly connected to the transmission.Most FR vehicles use this system because it

delivers fast shift operations and feels good to operate.

(3) Shift leverThe shift lever can be move horizontally to select the gear row (select movement), and forward

and back to move the gears (shift movement).

These movements move the internal parts of the transmission to change gear.

A gear is added to reverse the direction of rotation.


(4) Transmission operation1) Gear changeThe movement of the shift lever is transmitted unchanged to the gear shift selector lever inside the transmission.When the gear shift selector lever moves in the vertical direction shown in the figure to select and

rotate a gear, it moves the synchro hub and meshes the gear with the main shaft.

2) What is the synchromesh mechanism?

The synchromesh mechanism selects the gear to mesh wi th the main shaf t by moving the synchronizer sleeve. When in neutral, the gears on the main shaft rotate at a speed that is a multiple of the teeth ratio (reduction ratio) of the gears that

oppose the rotation speed of the countershaft. This means that the main shaft (synchronizer hub)

rotation speed and the rotation speeds of the gears on the main shaft are different. When the gears are changed, the synchromesh mechanism absorbs this rotation difference to ensure a smooth change.

3) Synchromesh mechanism structure

Gear shift shaft

3026

Gear shift yoke

Gear shift arm

Synchronizer hub

GearGear

Shift fork

Gear shift shaft

Gear shift selector lever

Gear shift selector shaft

Gear shift control shaft

Gear shift selector lever

Synchronizer key

Synchronizer sleeveSynchronizer ring

Cone

Synchronizer spring

Synchronizer hub Groove

Cone

3117

Gear

Synchronizer

sleeve

Synchronizer spring

Synchronizer ring

Synchronizer key

Synchronizer hub


4) Synchromesh mechanism operation- 1st stage synchronization action 1. When the shift fork moves the synchronizer

sleeve (referred to as sleeve from now on),

the sleeve and the meshed key move together to the right.

2. The end of the key pushes the ring against the

cone. This frictional force transmits the rotation force of the sleeve to the gear.

3. At this time, the difference between the rotation

speeds of the ring and gear and the friction with the cone shifts the rotation direction of the gear just by the difference between the key

groove width and the key width. As such, when seen from above, the splines on the inside of the sleeve and the ends of the ring splines face each other in different positions as shown in Figure A.

Protrusion Sleeve

Ring

Gear

Key

Sleeve

Ring

Gear

Ring splineSleeve spline

Cone

Key

3028

Figure A

Sleeve

Ring

Gear

Sleeve

Ring

Gear

Strongly pushes without

going forward

Cone

Key

Spring

Sleeve

Ring

Gear

Sleeve

Ring

Gear

Forward

(Synchronization

completed)

Cone

Key

3030

- 3rd stage synchronization meshing 1. The sleeve and gear rotation speeds are

equalized, and the ring is freed in the rotation direction.

2. As shown in the figure, the splines on the inside

of the sleeve push away the ring splines and move smoothly to mesh with the gear splines.

3. If there is a rotation difference between the ring

or gear and the sleeve, the frictional force of the ring and the gear cone stops the forward movement of the sleeve. It only allows forward movement after synchronization is completed. However, when the synchronization action

(frictional force) is weak, there is a gear noise

when meshing with the gear and gear shifting is difficult.

- 2nd stage synchronization action 1. As the shift lever is moved, the force acting on

the sleeve overcomes the spring. The sleeve goes over the key protrusion and moves forward (moves to the right in the figure).

2. The splines on the inside of the sleeve and the

ring splines hit against each other. 3. The force applied to the sleeve is transmitted

via the splines that continue to hit and contact each other, and strongly pushes the ring into the gear cone. This frictional force performs a strong synchronization action.


6) IBS structureThe IBS is made up of a 5th speed synchronizer sleeve, 5th speed synchronizer hub, 5th speed synchronizer

lever, 5th speed synchronizer ring and input shaft 5th gear.

5th speed synchronizer sleeve

5th speed synchronizer hub

5th speed synchronizer lever

5th speed synchronizer ring

Input shaft 5th gear

3P03

5) What is IBS (input shaft brake system)?When shifting into reverse, even if you step on the clutch to cut off the power from the engine, inertial force continues to rotate the input shaft. This means that when shifting into reverse, the reverse gear of the input shaft that continues to rotate and the reverse idler gear that is stationary are not synchronized. This results in poor shifting into reverse gear and a gear noise. To minimize this effect, the IBS applies a brake to the

input shaft with the 5th speed synchronizer ring to reduce the rotation speed and ensure a smooth shift into reverse.

Input shaft Input shaft

Reverse gear

Reverse idler gear Reverse idler gear

Reverse gear

:Rotation :Brake

5th gear

IBS

3P46


7) IBS operation- When in neutralWhen the input shaft is rotating due to inertial force, the 5th speed synchronizer sleeve and 5th speed synchronizer lever also rotate. As such, the 5th speed synchronizer lever pushes out toward the circumference due to centrifugal force. This meshes the flange of the 5th speed synchronizer lever with the

groove of the 5th speed synchronizer sleeve.


Mesh

Input shaft

:Input shaft rotation

:Centrifugal force

3P04



Groove of 5th speed synchronizer sleeve

Flange of 5th speed synchronizer lever


3P47


Reverse idler gear

:Rotating area Differential assembly

Input shaft

Countershaft

Reverse gear5th speed synchronizer sleeve



- Start of synchronizationWhen shifting into reverse, the 5th gear shift fork moves the 5th speed synchronizer sleeve in the direction of arrow A. At this time, the 5th speed synchronizer lever moves the flange of the 5th speed synchronizer

lever in the direction of arrow B, with the 5th speed synchronizer hub as the fulcrum because the 5th speed

synchronizer hub is fixed to the input shaft. This means that the 5th speed synchronizer lever pushes the 5th

speed synchronizer ring, so that the 5th speed synchronizer ring and the cone surface of the input shaft 5th gear make contact. This applies a brake to the input shaft, reducing its speed. As such, it is easier for the reverse idler gear and the input shaft reverse gear to mesh, enabling a smooth shift into reverse.

3P48


Reverse idler gear

Differential assembly

Input shaft

Countershaft

Reverse gear




Fulcrum


Cone surface


Input shaft


:Shift fork movement

:Synchronizer lever pulling force

:Synchronizer ring pushing force

:5th gear cone surface pushing force

5th gear shift fork




A

A

BB

B

B

B

3P05









- Gear change completionWhen the 5th speed synchronizer sleeve moves further in the direction of arrow A, the 5th speed synchronizer lever is pushed in the direction of arrow C. This eliminates the force of the 5th speed

synchronizer lever pushing against the 5th speed synchronizer ring. At this time, the 5th speed synchronizer ring and the cone surface of the input shaft 5th gear separate, which releases the brake that was applied to the input shaft. This means that after the gear change is completed, the input shaft can rotate again.

C

C

Input shaft





A


:Shift fork movement

:Synchronizer lever pulling force


A

C

C

Cone surface




3P06

3P49



Reverse idler gear


:Power transmission routeDifferential assembly

Input shaft

Countershaft

Reverse gear


Gear spline

ChamferSleeve splineSleeve

Tape

red

surf

ace

3031

(5) Mechanisms for safe drivingA manual transmission has various mechanisms for safe driving. These include a mechanism for preventing a meshed gear from jumping out while

driving, a mechanism for preventing more than one gear from meshing to the main shaft at the same time, and a mechanism for preventing the vehicle from being mistakenly put into reverse while driving.

1) Gear jump out prevention mechanismGear jump out is when a gear jumps out without a shift

operation. It often occurs because of changes in vibration or load while driving, such as during sudden acceleration or deceleration. If the gear jumps out, the transmission goes into neutral.

Gear jump out is often caused by gears meshing in a defective

way at the moment of shifting or by a shift in the positional relationship between the sleeve and gear while driving due to wear on the splines between the synchronizer sleeve and the gear resulting in an excessive thrust clearance.

- ChamferThe sleeve and gear spline fittings have tapered teeth surfaces.

During rotation, the gear spline is driven by the tapered surface,

which makes it difficult for the gear to jump out.

Spring

Detent ball

Shift fork shaft

Shift fork shaft

3032

- Detent ballThe detent ball is pushed into the ball groove on the shift fork shaft by the spring. This prevents gear jump

out and gives a good operating feel when shifting.

2) Reverse gear shift lever 1-way movement mechanism

In a manual transmission, the shift lever is operated to move the various shift fork shafts. The gear shift forks that are integrated with the shift fork shafts move to change the gears.In recent Suzuki vehicles, changing to reverse has been performed not by the sleeve movement, but by the movement of the reverse idler gear. Longitudinal manual transmissions use a reverse

gear shift lever 1-way movement mechanism. When

a shift operation is made that involves a movement in the direction of the 5th gear side and the reverse side of the 5th-reverse shift fork, the reverse gear shift lever 1-way movement mechanism is activated

only when the reverse gear shift lever is operated to one side (reverse side). This mechanism moves the

reverse idler gear.

- When in neutralWhen in neutral, because the pin of the 5th-reverse gear shift fork restricts the rotation of the reverse gear shift lever, the reverse idler gear does not move.

3P07

Reverse idler gear

5th-reverse gear shift fork

Groove of reverse gear shift lever

Pin of 5th-reverse gear shift fork

Reverse gear shift lever


3P08


Reverse idler gear




- ReversingWhen shifting from neutral to reverse, the pin of the 5th-reverse shift fork moves along the groove of the reverse gear shift lever, applying force to the reverse gear shift lever in the clockwise direction. The clockwise rotation of the reverse gear shift lever moves the reverse idler gear and fits it into the

input shaft.

3P09





Reverse idler gear

- When in the 5th speedWhen shifting from neutral to the 5th gear, the pin of the 5th-reverse gear shift fork moves inside the groove of the reverse gear shift lever, but because rotation force is not applied to the reverse gear shift lever, the reverse idler gear does not move.

- Transverse manual transmissionWhen shifting to 1st or 2nd gear, locking ball A that

is pushed out by the low speed shift shaft moves the pin and locking ball B. The balls enter the

grooves of the high speed shift shaft and the 5th shift shaft to regulate the movement of these shift shafts.

5th shift shaft

Transmission case

Locking

ball B

High speed shift shaft

Locking ball A

Pin

Low speed shift shaft

3) Double meshing prevention mechanism (interlock mechanism)

If 2 adjacent shift forks move at the same time,

there is a risk of 2 gears meshing.

To prevent this, a double meshing prevention mechanism (interlock mechanism) is used.

5th shift shaft

Locking

ball B

Transmission case


Pin

Locking ball A


When shifting to 3rd or 4th gear, the high speed

shift shaft moves locking balls A and B, which enter

the grooves of the low speed shift shaft and the 5th shift shaft to regulate the movement in the shift direction.

When shifting to 5th or reverse gear, locking ball B

that is pushed out by the 5th shift shaft moves the pin and locking ball A. The balls enter the grooves of the low speed shift shaft and the high speed shift shaft to regulate the movement in the shift direction.

5th shift shaft

Locking

ball B

Transmission case


Pin

Locking ball A



- Longitudinal manual transmissionThe lever of the gear shift selector arm and the lever of the gear shift interlock lever are always meshed in the yoke grooves.

Gear shift interlock lever

Yoke

Gear shift selector arm Lever of gear shift

interlock lever

Yoke

View from above Front view

Lever of gear shift selector arm


Lever of gear shift interlock lever

Yoke

3P10

The lever of the gear shift selector arm can move in both the select direction and in the shift direction. However, the lever of the gear shift interlock lever can only move in the select direction.



3P11


This means that only the yokes that are meshed with the lever of the gear shift selector arm can move in the shift direction. The movement of the yokes that are meshed with the lever of the gear shift interlock lever is restricted in the shift direction.


Gear shift selector arm


Yoke





Yoke

3P12

If the gear shift selector arm is shifted while it is in a middle position between Neutral and 1-2 or Neutral

and 5-R, the shift cannot be made because the yokes make contact with the lever of the gear shift interlock

lever.





Yoke


YokeLever of gear shift selector arm

3P13


2. The 5th-reverse gear shift cam that shifts to

5th gear rotates, and the reaction force of the cam guide return spring moves the 5th-reverse interlock plate one step to the rear.

Cam guide return spring

5th-reverse gear shift cam

5th-reverse interlock plate

3037

3038Gear shift selector shaft

5th-reverse gear shift cam


Low select spring


3039

Gear shift selector shaft

Cam guide return spring

Gear shift guide case

Guide bolt5th-reverse interlock plate

Compressed

Compressed

Low select spring

3036 4. When the shift lever is returned to the neutral position, the reaction force of the low select spring returns the 5th-reverse interlock plate to its normal position, which allows shifting to reverse.

3. If shift ing to reverse is performed in this

condition, the gear shift selector shaft rotates, and the 5th-reverse gear shift cam continues to be pushed by the 5th-reverse interlock plate. This means that the shifting cannot be performed.

4) Inadvertent reverse operation prevention mechanism

An inadvertent reverse gear operation is when the gear jumps out from 5th gear, and through its own

momentum, enters the reverse gear.To prevent this, the mechanism is designed so that a shift to reverse gear cannot be made without first

returning the shift lever to neutral.

- Transverse manual transmission 1. When the shift lever is moved to the 5th gear,

the gear shift selector shaft is pushed in the gear shift guide case direction. At this time, the movement of the 5th-reverse interlock plate is regulated by the guide bolt, and the low select spring and the cam guide return spring are compressed.


- Longitudinal manual transmission 1. When the shift lever is moved to the 5th gear,

the gear shift selector arm that is integrated with the gear shift shaft rotates. At this time, because the lever of the gear shift selector arm pushes the ratchet cam, the ratchet compresses the ratchet spring and rotates.

Ratchet spring

Ratchet

Cam

Lever of gear shift

selector arm

3P14

2. When shift ing to 5th gear, the gear shift

selector arm slides, and the ratchet cam is freed from the pushing force of the lever of the gear shift selector arm. As a result, the reaction force of the ratchet spring returns the ratchet to its normal position.

Gear shift

selector arm

Ratchet spring

Ratchet

Lever

Cam

3P15

3. If the driver tries to shift straight from 5th gear

to reverse, the gear shift selector arm tries to slide. But because the lever and the ratchet

cam make contact with each other, the shifting cannot be performed.

4. When the shift lever is returned to the neutral position, because the movement of the gear shift selector arm is no longer restricted by the ratchet cam, the shift to reverse can be performed.

Gear shift

selector arm

Ratchet

Lever

Cam

3P16

Ratchet

Lever

Cam

Gear shift

selector arm

3P17


(6) Internal transmission lubrication

Oil lubrication inside the transmission is performed

with a gear that releases oil, and by supplying oil through the oil channels inside the shaft. This lubrication improves durability and reliability.

1) Input shaft internal lubricationOil that is released by the final gear runs into the

input oil gutter in the left case through centrifugal force. It is guided from the input oil gutter to the side cover, and then to the oil channel inside the input shaft through the oil pipe that is integrated with the side cover.The oil that is guided inside the input shaft flows from the oil holes in the 5th hub, 4th gear and high speed hub to lubricate the various parts.

2) Countershaft internal lubricationOil that is released by the final gear runs into the

oil pan of the right case bearing through centrifugal force. I t is gu ided to the o i l channel in the countershaft.The oil that is guided inside the countershaft flows

from the oil holes in the low speed hub and 2nd

gear to lubricate the various parts.

[2] Overhaul(1) Important points for disassemblyThere may be various reasons for disassembling the transmission, such as abnormal noise or stiff shifting.But before performing the disassembly, you must

first check for possible causes in locations other than the transmission unit. For example, if the shift

operation is stiff, if you disconnect the gear shift control cable on the transmission side and check the shift lever movement, you can judge whether or

not the cause is on the transmission side.With some transmission types, actual parts can be moved to identify the cause while only one side of the case is disconnected (before disassembling the transmission). These include the condition of the

gear backlash and gear meshing, the chattering of each shaft, and the smoothness of the rotation of each gear and shaft.Arrange the disassembled parts so that you remember to which system they belong. Be especially careful of

transmission internal parts, because many of these parts have a specific assembly direction. Make sure

that you remember the correct assembly method by taking notes or marking the parts.

(2) Check of internal transmission parts

1) Transmission case checkCheck mainly for cracks and that the breather plug

functions properly. If the plug is clogged, clean it.

2) Gear teeth surface checkCheck the gear teeth surfaces for excessive wear

or damage. If a gear is worn or damaged, replace it because it may cause abnormal noise.

3) Bearing checkClean the ball bearings and roller bearings and then

rotate them. Check that they operate smoothly and

do not catch. Also check the parts equivalent to the outer race and inner race in the taper roller bearing, and replace them as a set if there are any problems. Check the bushes for wear, streaks and cracks, and

replace them as a set if there are any problems.

Input oil gutterRight case

Left case3040

Side cover

Oil pipe

Input shaft

Countershaft

Right case bearing

Final gear


4) Synchromesh mechanism check 1. I f the clearance is equal to or below the

specified value when the synchronizer ring and

its partner gear are pushed together, replace the synchronizer ring. Also, if there is major

wear on the gear cone, replace as a set.

7) Check of parts in the interlock mechanism and gear jump out prevention mechanism

Check parts such as the interlock pin, spring and

locking balls, and replace if there are any problems such as damage, attenuation or wear.

(3) Important points for assemblyThe important points for assembly are to make sure that the correct parts are installed in the correct areas, in the correct direction and in the correct position. Information such as the allowance of each part before disassembly and the force required for operations must be noted down in advance. By performing this check in every stage, you

can prevent maintenance mistakes, such as discovering after reassembly that the gears are too stiff to shift.

[3] Failure diagnosisThe transmission is connected to the engine, and its rotation speed changes in proportion to the vehicle speed and together with the differential and tires. As such, if a problem occurs, the cause is not necessarily in the transmission. When performing failure diagnosis for the transmission, first the conditions and phenomena

under which the problems occur must be checked and the structure understood. The possible locations must then be narrowed down to find the cause.

(1) Abnormal noiseMost of the parts inside the transmission are sliding parts,

such as gears, bearings and the synchro-mechanism. If all parts in the transmission are covered by an oil film

they will not wear. But if wearing occurs, chattering will

occur in the sliding parts, resulting in abnormal noise. So in general, the conditions under which the abnormal noise occurs must be identified, and the operating parts

that are related to these conditions must be checked.Sometimes abnormal noise occurs only when driving with certain gears or only when shifting to certain gears. Under such conditions, the method described above

can be used to identify the problem. But if the problem

occurs across all driving ranges, the cause may be in many different locations, such as the differential, wheel hub, clutch, propeller shaft and drive shaft.

Clearance Gear

Cone

Synchronizer ring

3041

3118

Synchronizer sleeve

Gear shift fork

Slide gauge

2. Replace if there is significant wear on the

synchronizer key protrusion. Check for wear on

the synchronizer sleeve that covers the protrusion. 3. Replace if there is any breaking or attenuation

on the key spring.

5) Shift lever checkCheck for wear on the ball on the end of the shift

lever, and replace if there are any problems.

6) Shift fork checkMeasure the thickness of each shift fork claw and

the width of the synchronizer sleeve groove, and replace if their values deviate from the standard.


(2) Gear engagement and disengagement problems

Likely gear shift operation problems are (1) shift

lever to gear shift control cable, and (2) shift shaft

to shift fork to synchro-mechanism. When the transmission side of the gear shift control cable is disconnected and the shift lever is operated, if the movement is stiff, the problem is likely to be in system (1) above. If the movement is light, the

problem is likely to be in system (2).

During normal shift operation, the driver steps on

the clutch and the engine power is not transmitted to the transmission. For this reason, the same

problems occur if the clutch is not fully disengaged.

(3) Gear jump outGear jump out may occur more easily during a

sudden forward movement.Gear jump out may occur because of changes

in vibration or load after the gears meshed in a defective way at the moment of shifting. Or it may

occur because part wearing caused a shift in the positional relationship between the synchronizer sleeve and gear. To make a final identification of the

cause, the transmission must be disassembled.To check, shift to the gear that has the problem and make sure it is properly meshed. Repeatedly

perform sudden acceleration and deceleration to generate sudden forward movements, and check the gear jump out phenomenon. Also carefully

check the shift feeling (operation feel, weight) while

operating the shift.

(4) Oil leaksClean the location where you suspect there is an

oil leak. Perform a driving test and check the oil

leak location. Be aware that breather clogging and

overfilling may cause oil leaks.


4WD is an abbreviation of 4-wheel drive and

is used to describe 4-wheel drive vehicles.

Different drive systems include part-time 4WD

systems that can be switched between 2WD and

4WD; full-time 4WD systems that always drive

both the front and rear wheels; and real-time 4WD

systems that detect the driving conditions and automatically switch between 2WD and 4WD.

Di f fe rent fu l l - t ime 4WD sys tems inc lude a

rotary blade coupl ing (RBC) type and axia l

plunger pump coupling (AXC) type that limit the

differential mechanically with hydraulic pressure; a viscous coupling type that limits the differential through the viscous resistance of the silicone oil; a torque-sensitive cam type that limits the differential mechanically with frictional force; and an electromagnetic control device (EMCD) that

continuously switches between 2WD and 4WD

through electronic control based on the driving conditions.Note that full-time 4WD systems use a differential

that absorbs the rotation difference between the front axle and rear axle when turning.

3043Propeller shaft

Propeller shaft

Propeller shaft

Transfer

Transmission

Front wheel Rear wheel

The transfer may be separate from the transmission or it may be integrated with the transmission. It transmits the engine power to the front and rear wheels through a propeller shaft or drive shaft.

3. TransferWhen driving on uneven or slippery roads or climbing steep slopes is difficult for a 2-wheel drive

(2WD) vehicle where drive is supplied only to the

rear wheels or front wheels, the remaining tires are also used as drive wheels. 4-wheel drive (4WD)

vehicles have a mechanism for splitting the engine power between the rear wheels and the front wheels. This mechanism is called the transfer.


[1] Structure and operation(1) Part-time 4WD, separate from the transmission (Jimny: SN413)1) Part structureThe components in this type include an input shaft, drive chain, front output shaft, rear output shaft, counter gear and associated gears, hub, sleeve and shift shaft.The high-low clutch sleeve of the rear output shaft is used to switch between the low range and the high range. The sleeve on the front output shaft side is used to switch between 2WD and 4WD.

Input shaft

Counter gear

High-low clutch sleeve

Drive chain

Speed meter sensor ring

Rear output shaftOutput gear

T/F actuator2-4 shift fork

Front clutch hub

Front output shaft

Fixed shift shaft

T/F 4WD switch T/F L4 switch

Movable shift shaft

Front clutch sleeve High-low

shift fork


2) Operation- 2H positionThe driving force from the transmission is input to the input shaft and transmitted from the input shaft to the output gear via the drive chain. At this time, because the output gear and rear output shaft are fitted to each

other, the driving force is transmitted to the rear output shaft by the high-low clutch sleeve.Note that because the front clutch hub is not fitted to the front output shaft, the driving force is not transmitted

to the front output shaft.

Input shaft

Counter gear

Drive chain

Rear output shaft

Output gear

T/F actuator

Front output shaft

Front clutch hub

Front clutch sleeve

Fixed shift shaft

Movable shift shaft

T/F 4WD switch (OFF) T/F L4 switch (OFF)


4WD/4L indicator (in the combination meter)


- 4H positionWhen the driver pushes the 4WD switch of the 2WD/4WD selector switch and shifts into the 4H position, the

motor of the T/F actuator rotates and the movable shift shaft shifts in the direction of arrow A. The pin that is

installed on the 2-4 shift fork fits into the groove of the movable shift shaft and moves the 2-4 shift fork in the

same direction as the movable shift shaft. As a result, the front clutch sleeve moves in the direction of arrow B.

In the same way as when in the 2H position, the driving force from the transmission is transmitted from the

input shaft to the rear output shaft via the drive chain. However, because the front clutch hub is fitted to the

front output shaft by the front clutch sleeve, the driving force is also transmitted to the front output shaft.

Input shaft

Counter gearDrive chain

Rear output shaft

Output gear

T/F actuator

Front clutch sleeve

Front clutch hub

2-4 shift forkFixed shift shaft

Movable shift shaft

T/F 4WD switch (ON)

Groove

Pin

T/F L4 switch (OFF)


Front output shaft



- 4L positionWhen the driver pushes the 4WD-L switch of the 2WD/4WD selector switch and shifts into the 4L position,

the motor of the T/F actuator rotates and the movable shift shaft shifts in the direction of arrow A. At this time,

the snap ring that is installed on the movable shift shaft moves the high-low shift fork in the same direction as the movable shift shaft. As a result, the high-low clutch sleeve moves in the direction of arrow B.

The driving force from the transmission is input to the input shaft and transmitted to the output gear via the drive chain. At this time, because the output low gear and rear output shaft are fitted to each other by the

high-low clutch sleeve, the driving force is reduced with the output low gear via the counter gear, and is transmitted to the rear output shaft.In the same way as when in the 4H position, because the front clutch hub is fitted to the front output shaft by

the front clutch sleeve, the driving force from the rear output shaft is transmitted to the front output shaft.

Input shaft

Counter gear

Drive chain

Output gear

Rear output shaft

Output low gear

High-low shift fork

T/F actuator

Front clutch sleeve

Movable shift shaft

T/F 4WD switch (ON)

Snap ring

T/F L4 switch (ON)


Front output shaft


Front clutch hub


(2) Full-time 4WD (Swift: RS413)1) Part structureThe components are an intermediate shaft, reduction drive gear, reduction driven gear, input bevel gear, output bevel pinion and flange.

2) OperationA The power transmitted from the front differential case is input to the reduction drive gear. The power is sent via the reduction driven gear to the input bevel gear, where its direction is changed by 90. It is

output to the output bevel pinion and transmitted to the propeller shaft.B The power transmitted from the front differential gear is input to the intermediate shaft. It passes

through the reduction drive gear and is transmitted to the right side drive shaft.

Reduction drive gear

Intermediate shaft

Left case

Right case

Reduction driven gear

Input bevel gear

Retainer shimSpacer

Output bevel pinion

Retainer

Flange


(3) Full-time 4WD (Grand Vitara: JB420)1) Part structureThe components in this type include an input gear, center LSD, front drive shaft, front drive chain, counter

gear, front output shaft, rear output shaft and associated gears, hub and sleeve. The center LSD is a torque-

sensitive cam type that has both a differential absorption function (differential function) and limited-slip

differential function (LSD function).

The drive modes are 4H (center LSD unlocked), 4HL (center LSD locked), 4LL (center LSD locked) and

neutral. Switching between these modes is performed by the T/F actuator, when the driver operates a

selection dial on the center console.

Input gear

High-low shift fork

Low gear

Front drive shaft

Transfer oil pipe

Counter gear

Front output shaft

Center LSD rear drive cam

Reduction shift sleeve

Center LSD case

Center LSD rear drive follower

Center LSD front drive cam

Differential lock shift fork

Differential lock clutch sleeve

Front drive sprocket bush

Front drive chain

Front drive sprocket

Rear output shaft


2) Operation- 4H position (center LSD unlocked)In this position, the reduction shift sleeve is fitted to the input gear and the center LSD case, and the

differential lock clutch sleeve is fitted to the front drive shaft and the front drive sprocket.

This means that the driving force from the transmission is transmitted to the rear output shaft and front output shaft via the route shown in the figure.

When the vehicle turns, a difference in rotation speed occurs between the input gear, rear output shaft and front output shaft. The drive follower in the center LSD moves in a reciprocating action between the drive

cams to absorb the difference in rotation speeds. When slip occurs at the front and rear wheels, frictional force between the drive follower and drive cam is generated from the difference in rotation of the front drive cam and the rear drive cam. This friction limits the slip differential for the drive cam on the side that is not slipping, transmitting the driving force to vehicle wheels.

Input gear


Center LSD case

Front output shaft

:Rear side transmission route

:Front side transmission route


Rear output shaft

Front drive chain

Front drive shaft


3P39

Center LSD case

Drive follower Front drive cam

Rear drive cam


- 4HL position (center LSD locked)In this position, the reduction shift sleeve is fitted to the input gear and the center LSD case, and the

differential lock clutch sleeve is fitted to the front drive shaft, the front drive sprocket and the front drive

sprocket bush.This means that the driving force from the transmission is transmitted to the rear output shaft and front output shaft via the route shown in the figure.

Front output shaft




Input gear


Center LSD case

Rear output shaft

Front drive chain

Front drive shaft


3P40


- N positionIn this position, the reduction sleeve is fitted to the center LSD case only.

The driving force from the transmission is input to the input gear, but because the reduction sleeve is not fitted to the input gear, the driving force is not transmitted.

Front output shaft



Front drive chain


Rear output shaft

3P41

Input gear


Center LSD case


- 4LL position (center LSD locked)In this position, the reduction shift sleeve is fitted to the low gear and center LSD case, and the differential

lock clutch sleeve is fitted to the front drive shaft, front drive sprocket and front drive sprocket bush.

This means that the driving force from the transmission is transmitted to the rear output shaft and front output shaft via the route shown in the figure.

Front output shaft




3P42

Input gear


Low gear

Center LSD case

Rear output shaft

Front drive chain

Front drive shaft


Front drive sprocket bush


When a part-time 4WD vehicle is driven in

4-wheel drive, the front and rear propeller shafts are connected and the rotation speeds of the front and rear axles are the same. For this

reason, when driving on a sharp curve on a dry, paved road, the difference in the turning radius between the front and rear wheels results in a rotation difference between the tires (drive shaft rotation difference). It feels like brakes

are being applied to the front wheels. The rear wheels feel like they are slipping. This is called the phenomenon of tight corner braking.To e l i m i n a t e t h e t i g h t c o r n e r b r a k i n g phenomenon, full-time 4WD vehicles have a

mechanism that absorbs the rotation difference. It is positioned in the area that transmits the driving force of the front and rear axles. This mechanism enables stable driving that is not affected by road conditions or the weather, allowing driving in 4-wheel drive at all times.

(4) Synchro-mechanism1) Double cone synchro-mechanism The components of the double cone synchro-mechanism are a front drive hub, front drive sleeve, synchronizer key, spring, outer ring, center cone and inner ring.

3054

Front drive hub

Synchronizer keyFront drive sleeve

Drive sprocket

Spring

Outer ring

Inner ring

Center cone

Synchronizer keyFront drive

sleeve

Spring

Front

drive

hub

Plate

Outer ring

Center cone

Inner ring

Drive

sprocket

3119


When the driver shifts the transfer lever from 2H to

4H, the front drive sleeve (referred to as sleeve

from now on) moves to the right. At this time, the

synchronizer key (referred to as key from now on) also moves to the right. The end of the key

makes contact with outer ring, and so the outer ring also moves to the right. As the outer ring moves further to the right, it makes contact with center cone surface A. As the center cone moves to the right, center cone surface B and the inner ring

make contact and generate frictional force. This frictional force rotates the outer ring as far as a position opposite to the spline chamfer surface. The sleeve and the outer ring make contact with each other through their chamfer surfaces, transmitting the operation force to the outer ring. This operation force generates an even greater frictional force between center cone surfaces A and B, which has

a synchronizing action that reduces the difference in rotation speeds between the sleeve and the drive sprocket.

The synchronization action continues until there is no difference in rotation speeds between the sleeve and the outer ring. As the sleeve is moved further to the right, the spline chamfer surface of the sleeve slides and moves the spline chamfer surface of the outer ring, and the sleeve and outer ring are fitted

together by their splines. As the sleeve is moved further to the right, the spline chamfer surfaces of the sleeve and drive sprocket make contact.

Front drive sleeve

Outer ring

Outer ring spline

Center cone surface A

Center cone surface B

Drive sprocket

Drive sprocket spline

Synchronizer key

Sleeve spline

3056

Chamfer surface

Front drive sleeve

Outer ring

Outer ring spline



Chamfer surface

Drive sprocket

Inner ring


Synchronizer key

Sleeve spline

3055


The synchronization action continues until there is no difference in rotation speeds between the sleeve and the drive sprocket. As the sleeve is moved further to the right, the spline chamfer surface of the sleeve slides and moves the spline chamfer surface of the drive sprocket, and the sleeve and drive sprocket are fitted together by their splines. This completes the synchronization.

[2] Checks and maintenanceIn the same way as for the transmission, there may be various reasons for disassembling the transfer, such as abnormal noise or stiff shift ing. The possible causes and the check methods are the same as for the transmission.

Front drive sleeve

Outer ring

Outer ring spline



Drive sprocket


Synchronizer key

Sleeve spline

3057

Synchro-mechanism parts (synchronization action parts)

Drive sprocket

3058

Front drive sleeve

Outer ring

Center cone

Inner ring

Synchronizer key

Power transmission route


(2) Constant velocity universal joint

A constant velocity universal joint is used on the

drive shaft in areas that transmit power with a large angle, such as a front-wheel drive vehicle and rear axle shaft in a rear-wheel drive independent suspension vehicle. The structure of a constant velocity universal joint is complex, but is designed

so that no rotation speed changes occur in the driving axle and driven axle. This means there are no variations in the rotation speed and torque of the driving axle and driven axle, enabling smooth power transmission.

- Barfieldjoint

The bar field joint components include an inner race

and outer race that have guide grooves, and steel balls inside these guide grooves and a ball gauge that holds these balls.When the 2 axles rotate while at an angle to each

other, the spherical surfaces of the outer race and inner race change the angle while sliding in the groove direction. The steel balls sandwiched between the races transmit the power while rolling inside the guide grooves. This mechanism that absorbs the changes in angle maintains the same rotation speed for the driving axle and driven axle. This means that the power is transmitted smoothly without any variations in the rotation speed and torque of the driven axle.

3065

Drive shaft

Constant velocity universal joint

Final gear differential

4. Drive shaftThe dr ive shaft is direct ly connected to the differential and is used for power transmission. It is frequently used in independent suspensions.

Drive shaft

3066

Inboard joint (sliding constant

velocity universal joint)

Outboard joint (fixed constant velocity

universal joint)

3067 Outer race

Outer race

Steel ballInner race

Ball gauge

[1] Structure and operation(1) Drive shaftBecause the drive shaft is subjected to impacts

from the road surface and to torque that is amplified

by the reduction action of the differential, its twisting strength and rigidity must be many times that of the propeller shaft. For this reason, it is a steel bar and

not hollow. To withstand these loads, the constant velocity universal joints on both shaft sides are also

made of strong material.In the same way as the propel ler shaft , the drive shaft has constant velocity universal joints

that can transmit rotation smoothly. A constant velocity universal joint is positioned on the sliding

mechanism that absorbs the changes in the length in the axial direction caused by the up-and-down movement of the tires while driving. Another constant velocity universal joint also accommodates

large changes in the angle when turning because the shaft length is short, or because of up-and-down tire movements.


- Triport jointThe triport joint components include a housing,

roller and spider.Its power transmission is the same as that of the bar field joint. But also, because it absorbs the

extension and contraction of the drive shaft caused by the up and down movement of the wheels, the roller can move along the housing groove in the axial direction.

[2] Checks and maintenance(1) Drive shaftBe careful of the following when disassembling the

drive shaft.- In the same way as for the propeller shaft, draw

reference marks on the parts.- Before removing the boot, wrap the end of the drive

shaft with tape to protect it from damage.

3068Housing

RollerSpider

Boot

3070

Boot

Tape

Drive shaft

- Assemble the boot band for the resin boot as shown in the figure relative to the rotation direction of the drive shaft when going forward. Properly mesh the protrusions with the grooves (3

locations).

ProtrusionGroove

Rotation direction

3P27

- Assemble the boot band for the rubber boot as shown in the figure relative to the rotation direction

of the drive shaft when going forward.

Rotation direction

3P28

When filling the boot with grease, be sure to fill to

the specified level. If the specified level is exceeded

it will cause grease leaks, while if the level is insufficient, the joint may seize.


3069

Open the bellows-shaped area of the boot and

check al l around it that there are no cracks. Replace the boot if it is torn, but if there is abnormal

noise, replace the boot by replacing the drive shaft assembly.

(2) Constant velocity universal joint

Move the joint up and down and to the left and right,

and check that the operation is smooth and that there is no significant rattling. Check that the parts

that move in the axial direction do not catch and operate smoothly.


5. Propeller shaftA propeller shaft transmits power from the transmission to the front or rear axle. It is used in FR vehicles and

4WD vehicles.

Universal joints are installed on both ends of a propeller shaft or drive shaft. Even if the installation angle of

the shaft changes, these joints make the shaft rotate smoothly for power transmission.

Propeller shaft

Rear propeller shaft

Front propeller shaft

Drive shaft

Front

Front

Universal joint

Transmission side

Universal joint

Differential side


[1] Structure and operation(1) Propeller shaftTo transmit the powerful force from the engine, the propeller shaft is made from a steel pipe that is lightweight with high twisting strength and bending rigidity, and which has excellent properties for high speed rotation.The installation position of the propeller shaft that connects the transmission and the differential is not level, but is rather at a certain angle. When driving on bumpy roads, the installation position changes through various different directions. In accordance with these angle and installation position changes, the propeller shaft extends, contracts and tilts. This makes the rotation smooth and transmits the power to the final gear.

The figure below shows the components of the propeller shaft. They include the universal joints that

respond to the angle changes, and the sleeve yoke and propeller shaft unit that respond to changes in length in the axial direction. On this shaft, balance

pieces are installed at the time of production to balance the shaft for rotation (prevent vibration and abnormal noise).

Sleeve yoke

Spider

Propeller shaft

Balance pieceUniversal

jointUniversal

joint

Needlebearing

3072

3073

Differential

Radial ball bearing

Propeller shaftTransmission

Center bearing

Rubber bush

(2) Center bearingIn high-performance vehicles or large vehicles where there is a long distance from the transmission to the driving axle, the propeller shaft is split into 2 or 3 shafts

to raise its critical rotation speed. An area near the rear end of each shaft is supported with a radial ball bearing. This bearing is called the center bearing, and it is installed via a rubber bush to prevent the transmission of vibration to the vehicle body during rotation.

Critical rotation speedBecause the propeller shaft rotates at a high

speed while receiving ever-changing engine torque, twisting vibration is easily generated. Also, the propeller shaft may bend, and if the weight is not balanced, then bending vibration may occur. If these vibrations and the natural frequencies of the propeller shaft match, it will damage the propeller shaft. This rotation speed is called the critical rotation speed.The critical rotation speed can be calculated with the equation below. The longer the shaft length, the lower the critical rotation speed.

d22d12

n :Critical rotation speed (rpm) l :Shaft length (mm) d2 :Shaft outside diameter (mm) d1 :Shaft bore (mm)

*When the propeller shaft is a hollow steel pipe


(3) Universal jointA hook joint is often used as the universal joint. A

hook joints components include 2 yokes (input side

and output side), a spider (cross-shaped axle) that

connects these yokes, and a needle roller bearing.

[2] Checks and maintenance(1) Propeller shaft checkCheck the bending of the propeller shaft if it was

subjected to an impact, such as in an accident.

Check the bending by placing the propeller shaft

on a V block and setting a dial gauge on its center.

Gently rotate the shaft and measure.3074

Bearing race

Needle roller bearing

Oil seal

Oil seal retainer

Yoke

Spider

Propeller shaft

Flange yoke

3075

Yoke

Yoke

3076

V block

Propellershaft

Dialgauge

3077

The bend amount is half the dial gauge reading (deflection). Before performing the measurement,

remove the shaft paint from the areas that will contact the V block and the dial gauge. If the bend

exceeds the specified value, replace the propeller

shaft.

(2) Universal joint checkIf the propeller shaft rattles, check for joint wear.

If there are any problems, replace the propeller shaft by replacing the assembly. The rattling rhythm of the abnormal noise from the propeller shaft is proportionate to the driving speed. It tends to be particularly loud when starting off from a stop and during deceleration (when the engine brake effect is transmitted to the drive system).

The universal joints advantages is that its structure

is simple and wearing is low. The disadvantage is that when the driving axle and driven axle rotate at a certain angle to each other, the driven axles rotation speed and the torque vary relative to the driving axle. To absorb these variations, the direction (phase) of the yokes that are connected

to the universal joint are made the same. This

counteracts the rotation speed variations that are generated in the propeller shaft, achieving smooth power transmission. However, if the angle of the

driven axle relative to the driving axle becomes too large, even when the direction of the yokes that are connected to the universal joint are made

the same, the rotation speed variations cannot be counteracted. For this reason, a universal joint is

only used for parts such as the propeller shaft that have relatively small angle variations.


(3) Important points for propeller shaft disassembly (Jimny: SN413)

1. Before removing the propeller shaft, draw

reference marks on the joint and flange. This

will make sure that you assemble the parts in the same position and maintain their balance.

(4) Important points for propeller shaft assembly (Jimny: SN413)

1. Be sure to apply grease to the spider bearing

race, and check that the entire roller on the inner side of the spider bearing race is within the home position.

Flange

Reference mark

Joint

3 - 4 mm

Special tool

Copper hammer

Metal plate

Spider

Bearing race

Yoke

3083

Bearing

Spider

Bearing

Grease

3. Insert the bearing race on the yoke side, and

hit the bearing race with a copper hammer until it is in the same plane as the outer side of the yoke. Insert the spider into the bearing race while making sure that the bearing race roller does not come apart.

When hitting the bearing race, place a metal plate over the bearing race to prevent damage to the yoke.

2. Use a new snap ring, spider and bearing for

assembly.

3. Hit the yoke with a plastic hammer to fully

remove it from the bearing race.

2. Use a special tool to push out the universal

joint about 3 to 4 mm from the flange yoke.

Before pushing out the joint, apply a permeable

lubricant between the bearing race and yoke race.


4. In the same way, insert the bearing race on the opposite side into the yoke, and hit the bearing race with a copper hammer until it is in the same plane as the outer side of the yoke.

Copper hammer

5. After assembly, check that both the shaft yoke and flange yoke move together smoothly.

6. C

Documents

Technical Level 2_01