Embed Size (px)
Citation preview
MeritorAxle & Brake Service ManualLM and LMC Series Axles including Disc and Drum Brake variants
2
Section Description Page
QUICK REFERENCE WARRANTY CHART 3
THE AXLE IDENTIFICATION PLATE 6Identifying the Axle Type, Identifying the Serial Number
INTRODUCTION TO THE LM AXLE RANGE 7
AXLE INSTALLATION 8
LM/LMC MAINTENANCE SCHEDULE 9
TECHNICAL DATA TABLES 10Table 1: Fastener Torque Values
1 LM/LMC DRUM BRAKE SERVICE 11
2 LM/LMC DISC BRAKE SERVICE 19
3 LM/LMC HUB SERVICE FOR DRUM BRAKES 29
4 LM/LMC HUB SERVICE FOR DISC BRAKES 39
5 ADDITIONAL PROCEDURES 41
INDEX
3
Quick Warranty Reference Chart
LMC and LM HubsAny component not referred to below is covered by a 1 yr / 100,000 km warranty for mechanical failure only.Labour costs can only be claimed at an agreed rate with Meritor Service Department prior to work commencing.For full warranty terms and conditions see ‘Meritor Warranty Terms and Conditions’ Publication No 4.84.1
1 yr / 100,000 km Hub cap & screws
1 yr / 100,000 km Hub cap & screws
3 yr / 300,000 km LM hub assembly
3 yr / 300,000 km Axle end fixings
1 yr / 100,000 km Hub cap gasket.
Mechanical failure only
1 yr / 100,000 km Oil Seal.
Mechanical failure only
LMC
LM
1 yr / 100,000 km Hub cap & screws
1 yr / 100,000 km Stake Washer
assemblyMechanical failure
only
1 yr / 100,000 km Oil Seal.
Mechanical failure only
1 yr / 100,000 km Hub cap & screws
1 yr / 100,000 km Hub cap gasket.
Mechanical failure only
5 yr / 500,000 kmAxle end nut
7 yr / 1,000,000 km LMC Hub assembly
(Disc brake hubassembly shown)
4
Quick Warranty Reference Chart
DX 195 Disc Brake for LM AxlesAny component not referred to below is covered by a 1 yr / 100,000 km warranty for mechanical failure only.Labour costs can only be claimed at an agreed rate with Meritor Service Department prior to work commencing.For full warranty terms and conditions see ‘Meritor Warranty Terms and Conditions’ Publication No 4.84.1
1 yr / 100,000 km Brake pad assemblies.Mechanical failure only
1 yr / 100,000 kmBrake retaining clips.
2 yrs/200,000 km Caliper assembly
1 yr / 100,000 kmABS components
2 yr / 200,000 km Brake rotor. Mechanical
Failure only
5
Quick Warranty Reference Chart
LM Axle shownAny component not referred to below is covered by a 1 yr / 100,000 km warranty for mechanical failure only.Labour costs can only be claimed at an agreed rate with Meritor Service Department prior to work commencing.For full warranty terms and conditions see ‘Meritor Warranty Terms and Conditions’ Publication No 4.84.1
1 yr / 100,000 km Brake shoe assemblies.Mechanical failure only
1 yr / 100,000 km Brake shoe assemblies.Mechanical failure only
1 yr / 100,000 kmRetaining spring
1 yr / 100,000 kmABS components
5 yr / 500,000 kmAxle beam weld
assembly, Ex works.Including Flexair
spring seat. (3 yr / 300,000 kmLM 9300 beam-non
Meritor welded)
2 yr / 200,000 kmCam roller assembly
2 yr / 200,000 kmCamshaft
2 yr / 200,000 kmCam bearing
3 yr / 300,000 km Brake drum. Mechanical
failure only
1 yr / 100,000 km Dust covers & screws
1 yr / 100,000 kmReturn spring
1 yr / 100,000 kmABS components
1 yr / 100,000 kmAssister Spring
2 yr / 200,000 kmAnchor pin assembly
Axle LetterCode Hub Configuration
C Cartridge bearing hub
M Standard bearing hub
Axle Nominal Highway Wall MaxSeries Rating, Kg Thickness Offset*
90 9000 13mm 460mm
**93** 9300 16mm 490mm
Axle LetterCode ISO 4107 Wheel Mounting Type
MX M22 x 1.5p wheel studs for single steel wheels
MXA M22 x 1.5p wheel studs for single alloy wheels
Axle Letter Exciter Ring SuitableCode Type For
W 100t Solid Ring WabcoBosch
Grau DGX & MGX100
6
LM & LMC Service
The Axle Identification PlateEvery axle leaving the Meritor factory is fitted with an identification plate which contains all the information needed to ensure the correct replacementparts are obtained.
Table ‘A’
Table ‘E’
Table ‘C’
WREXHAM LL12 0PB UKASSEMBLED IN THE EEC
AXLE TYPEAPPROVAL No P41ABS15STVZ0
SERIAL No A999999 H97 0000NOM CAPACITY 9300 KG V MAXCOMB CAPACITY 9300 KG 105 KM/H
L S 1 0 E
Anti-Lock Type(Table A) Steer Axle = S
Axle series loading(Table C)
Type of wheel bolts(Table E)
Hub configuration(Table B)
Brake Type(Table D)
Order Number Build Year
Build MonthNon Asbestos Brake Lining Sequential Number
AOR
R
IDENTIFYING THE SERIAL NUMBER
Table ‘B’
Axle LetterCode Brake Type
H Disc Brake
Q Drum Brake
Table ‘D’
QOR
H
Track – spring centres* Offset =
2
** For use with non Meritor air suspensions
The axle ratings shown are for normal highway use and any special applicationmust be approved by Meritor Technical Sales.
IDENTIFYING THE AXLE TYPEAll LM series axles are fitted with 10 stud, ISO 4107 spigot mount wheel fixings and asbestos free brake pads or linings as standard. Other options areas shown below.
7
LM & LMC Service
Introduction to the LM Axle RangeThe Meritor LM range of axles are manufactured to the same highstandards expected of all Meritor products.
The LM Series has been specifically designed, as its name implies, forLow Maintenance and hence reduced cost of ownership whilstfurthering Meritor’s reputation for low weight – especially when usedwith Meritor Flexair Suspension.
Its use is predominantly intended for tri-axle, on-highway applicationsrunning on super single tyres fitted to 22.5" wheel rims at combinedbogie weights up to 27 tonnes.
Introduction to the LMC ConceptThe LMC cartridge bearing hub is an innovative addition to the standardLM axle range, offering a fully sealed, maintenance free bearing unit –a unique feature in European trailer axles.
The LMC offers the optimum combination of bearing performance andreduced service times.
The cartridge bearing is manufactured to extreme levels of accuracyallowing it to be operated in a precisely controlled preloaded conditionfor optimum life performance
Whilst the hub can be left for up to 7 years without removal from thebeam, the sealed bearing allows for quick and clean routine brakeservicing should the hub need to be removed more frequently.
Introduction to Meritor DX195 DiscBrakeThe Meritor DX195 Air Disc Brake is one of a family of modular highperformance, low weight, high efficiency brakes designed for Trailers,Trucks, Coaches, Buses and other Commercial vehicles.
The brake has a cast caliper, which straddles the brake rotor andhouses two lining pads. Clamping force is produced by a standardindustry air chamber, amplified via a high efficiency shallow throweccentric and balance beam assembly.
The caliper is carried on a saddle which is a fixed support bolted to atorque plate on the axle beam.
Equalised clamping action on the inner and outer pads is generated byallowing the caliper to “float” on the two slide pins fixed to the saddle.Clamping force created by the primary actuation is applied to the innerpad, which forces it into contact with the rotor. Reactive force throughthe caliper body applies equal clamping force to the outer “Fixed” pad.
The slide pins also allow the caliper to freely position itself on thesaddle to compensate for the reduction in lining pad thickness due towear.
Lining wear would result in correspondingly longer actuation leverthrow and excessive chamber stroke. To eliminate the problem, thebrake incorporates an inbuilt automatic adjustment mechanism.
The auto-adjuster operates on each clamping action to sense excessivepad-rotor clearance, and reduces excessive clearance by a fixedproportion with each actuation.
For brake set up and new lining installation, the brake incorporatesprovision for manual adjustment, easily made using a standardHexagon key.
8
LM & LMC Service
The effects of welding will be minimised if:
(a) all tack welds are at least 25mm long.
(b) the number of tack welds is kept to a minimum. If possible clampthe bracket tightly to the beam and eliminate the tack welds.
(c) the welding procedure recommended in the Meritor suspensionmanual is followed.
(d) more than one weld run is required make the following run with adifferent start/finish point and before the previous run has cooleddown. Descale between runs.
(e) oil, rust and thick deposits of paint are removed from the surfacesto be joined.
(f) the welding consumables meet the relevant British Standards andare used as recommended by the manufacturer.
(g) at the end of fillet welds, the weld is ‘backed up’ to fill the crater.
The following precautions will prevent damage to the axle andsuspension during welding and improve service life:
(a) prevent weld spatter from falling on the axle and road springs.
(b) ensure the earth connection is made to the axle beam, preventingthe passage of current through the wheel bearings.
(c) do not test the arc on the axle beam or springs.
(d) remove scale and slag from fillet welds before painting to preventcorrosion.
DO NOT weld in this area top and bottom
WELD DETAILS: GENERAL REQUIREMENTS FOR AXLE BEAM
95
(50°)
Weld in this area both sides
Axle InstallationThe following notes and recommendations are offered as a guide to thetrailer manufacturer and service engineer. They are based onexperience gained from both the manufacture and servicing of singleand multiple axle installations.
LIMITATIONS OF USEThe following limitations apply to the LM series axles fitted with supersingle tyres and used in tandem or tri-axle arrangements.
For normal road and RO–RO use at 9 tonne axle weight the LM9000(13mm wall) beam is authorised for Meritor air and mechanicalsuspensions only when assembled by Meritor. In all other instances ofnormal road, RO–RO, and unrestricted tipper use at 9 tonne axle weightusing non-Meritor suspensions, air or mechanical, the LM9300 (16mmwall) beam must be used.
For extreme conditions, i.e. narrow frame centres (<1100mm), highcentre of gravity (>2000mm) please consult Meritor Technical SalesDepartment.
In cases where suspensions of non-Meritor manufacture are used, thetrailer builder or suspension manufacturer must satisfy themselves asto the suitability and compatibility of the axle and suspension,particularly from a durability standpoint. Meritor will be pleased toassist in assessing such compatibility, but cannot warrant the fitmentof its axles to suspensions of unknown characteristics.
STRESSES AND WELDINGDuring use the axle beam is subjected to a wide variety of forces.These are caused by the payload, bumps in the road surface, corneringand braking. Because these forces are constantly varying, the stressesin the axle beam also vary, causing fatigue. The top and bottom of thebeam generally experience the greatest stresses and hence the mostfatigue, whilst the section of beam around the horizontal centre linesees the least stress and fatigue.
Welds in the high stress areas will adversely affect the fatigue strength,for this reason do not weld in the area 95mm wide top and bottom ofthe beam, or 50° either side of the vertical centre line, as shown in thediagram below. Weld tacks or weld spatter are not allowed in this area.
The beam material is controlled to ensure that pre-heating is normallynot necessary when welding as per BS5135.
The direction of welding should be as near the horizontal as possibleand welding around the corners of brackets or spring seats should beavoided. Separate drawings exist on request from the Meritor TechnicalSales Department detailing seat welding procedures for both air andmechanical Meritor suspensions.
9
LM & LMC Service
FREQUENCYSERVICE ROUTINE
LM Axle Maintenance Schedule
LM, LMC – Disc & DrumCHECK BRAKE ADJUSTMENT ANDCHECK WHEEL NUT TORQUES:
• Before entering service.
• After 150 km.
• After 1500 km.
• Every 3 months.
• After any wheel fixing removal.
• After any brake service.
LM, LMC – DrumLUBRICATE CAMSHAFT BEARINGS:
• Recommended maximum at 3 monthly intervals.Note: If other than Meritor Brake Lubricant Total Fina is used or wherevehicles are in contact with severe abrasives a max of 6 week intervalnecessary.
LM, LMC – DrumBRAKE INSPECTION & SERVICE
• Linings should be inspected every 6 weeks or 25,000 kms and mustbe replaced as an axle set if worn down to the wear indicator (8mm).
Full stripdown should be prior to 2nd annual test or at 1st reline,whichever is soonest.
THENAnnually or at every subsequent brake reline. Whichever is mostfrequent.
LM – Disc & DrumHUB AND BEARING INSPECTION: INCLUDINGOIL SEAL REPLACEMENT
LMC – Disc & DrumHUB AND BEARING INSPECTION: INCLUDINGOIL SEAL REPLACEMENT
• Whenever hubs are removed from axle.
• Annually after 1st major hub overhaul.
LM – Disc & DrumMAJOR HUB SERVICE
• If a problem is found during inspection.
• Prior to 2nd annual test or after 300,000 km, whichever occurs first.
LM, LMC – DiscBRAKE INSPECTION & SERVICE
• Pads, caliper and rotor should be inspected every 50,000 kms or 3months. Pads must be replaced when worn to a minimum liningthickness of 3mm. Always replace pads as an axle set.
At intervals of 100,000 kms, or every 6 months, (preferably whenchanging pads), the opportunity should be taken to remove anyaccumulations of wear debris and rust from the edge of the rotor, andfrom the pad location points in the caliper. Check also condition andlocation of sealing boots.
The above service intervals are recommended maximums undernormal operating conditions. Unusual ambient temperatures oradverse operating conditions (e.g. dusty atmospheres or severegradients) will require more frequent service intervals. It is theresponsibility of the vehicle operator to establish these intervals.
• The LMC hub assembly is maintenance free. However a visualinspection should be carried out and the auxiliary oil seal replacedwhenever the hub is removed from the axle.
Note: The LMC hub is not a serviceable item. Any problems should be reported to Meritor Service Department.
10
LM & LMC Service
TABLE 2: FASTENER TORQUE VALUES – DISC BRAKE ONLY
Rotor flange bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230/270 NmCaliper retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280/320 NmBlanking plug adjuster access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10/17 NmLever clamp bolt/nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31/37 NmAir chamber nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175-200 Nm
Technical Data Tables
TABLE 1: FASTENER TORQUE VALUES – DRUM/DISC BRAKE
TABLE 3: RECOMMENDED LUBRICANTS
Hub cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11/15 NmDust cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50/60 NmDust cover nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11/15 NmSpherical bearing bolts (spline end) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50/60 NmSpherical bearing bolts (cam head end) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50/60 NmSensor fixing bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30/50 NmLM Axle lock nut . . . . . . . . . . . . . . . . . . . . . . . . Refer to setting procedure, Section 3.17Button head screws (axle lock nut) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15/20 NmLMC Axle lock nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .700/750 NmWheel nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 680/750 Nm
LM HubHub Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150-200 gmInner Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45-50 gmOuter Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45-50 gmHub Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nil
LMC HubHub is pre-packed no maintenance unit
Hub Bearings:Meritor Hub Grease, Blue Lithium EP2Elf Lithium EP2Total Multis EP2 Castrol Spheerol EPL2Shell Calithia EP2T Shell Alvania Grease EP(LF)2Texaco Multifak EP2 Mobil Mobilux EP2BP LS EP2 Fina Marson EPL2Silkolene G62 SKF LGEP2Eurol Universalfett EP2 GB Lithium EP2Axel Christiernsson Lithac 162 EP Esso Beacon EP2
Brake Components and Camshaft Bearings:Meritor Brake Lubricant – (Total Fina CERAN WRC2)
Spindle Bearing Journal:Optimol Optimoly White Paste T
TABLE 4: HUB & BEARING GREASE FILL VOLUMES
29
LM & LMC Service
Section 3
LM/LMCHub Service forDrum Brakes
30
LM & LMC Service
LM Hub and Bearing InspectionThe following procedures can be performed either with the road wheeland brake drum assembled to the hub or with the road wheel andbrake drum removed. In the latter instance refer to Sections 1.1-1.3.
For clarity, the brake drum has been removed in the followingphotographs.
3.1 DE-ADJUST BRAKESSee Section 1.1.
3.2 REMOVAL OF HUB LOCKNUTRemove the five M8 hub cap screws.
Remove hub cap and gasket (Fig. 1).
Remove the two socket button head screws using 5mm A/F Allen key(Fig. 2).
The hub locknut should be removed using hub nut spanner (Meritorpart number 21224839).
It is recommended that the retaining clip and retaining washer are leftin the hub until the hub assembly has been removed from the spindle.
3.3 REMOVAL OF HUBRemove the hub assembly from the axle using a hub puller (Meritorpart number 21224863). The five M8 hub cap screws may be used tosecure the hub puller to the hub face (Fig. 3).
If the hub is to be removed whilst still assembled to the road wheel andbrake drum, use a wheel dolly to support the weight of the assembly.
3.4 REMOVAL OF OIL SEAL AND INNER BEARINGCONEThe oil seal should be removed from the hub using an oil seal removalplate (Meritor part number 21224938) and suitable lever (Fig. 4).
THE SEAL MUST BE DISCARDED. NEVER RE-USE AN OIL SEAL AFTERTHE HUB HAS BEEN DISMOUNTED FROM THE AXLE SPINDLE.
Remove the inner bearing cone and place it in a clean area. Identify thebearing cone clearly to ensure that it is refitted to its original position inthe hub.
SECTION 3
FIG. 1
FIG. 2
FIG. 3
FIG. 4
31
LM & LMC Service
3.5 REMOVAL OF RETAINING WASHER AND OUTERBEARING CONEThe retaining clip can now be removed from the outer side of the hubwith a pair of pliers or suitable screw driver.
Remove the retaining washer (Fig. 5).
Remove the outer bearing cone and place it in a clean area. Identify thebearing cone clearly to ensure that it is refitted to its original position inthe hub.
3.6 CHECK GREASE CONDITIONIf the grease within the bearing is clean and does not appear burntthere should be no necessity to totally clean down the assembly.
Check the hub cavity for any grease contamination caused during hubremoval from the spindle. Any contamination must be removed or if thisis excessive a complete hub clean down must be carried out. Refer toSection 3.7.
3.7 CLEANING OF HUBWipe clean the hub cavity removing all the old grease and anycontamination.
3.8 INSPECT BEARINGSCheck both bearings, cones and raceways for:
Cage damageCorrosionRoller and raceway damage or pittingMetallic debris or flakingBearing cup security – Ensure both bearing cups are well secured inthe hub, by checking they are fully seated within the hub bore, andwith a good grip of the cups try to rotate them. If any movement of thecups is detected then the hub will have to be replaced. Do not attemptto fit new bearings into a hub with worn bores.
If any of the above defects are evident the complete bearing (cup andcone) MUST be replaced.
3.8.1 Replace Hub:It is advisable to replace with a complete new hub and bearingassembly which is available from Meritor Aftermarket Distributors.
3.8.2 Individual Bearing Replacement Procedure:Drift out the bearing cup from the hub ensuring that the bearing borewithin the hub is not damaged.
Bearing Cup Refitment:
ALWAYS USE GENUINE MERITOR BEARINGS – STANDARD ISOBEARINGS CANNOT BE USED.
Insert the bearing cup into the hub and using a bearing cup driver(Meritor part number 21225228) drive the cup fully home ensuring thecup sits squarely against the hub shoulder.
3.9 REGREASE BEARINGSThoroughly pack both bearing cones with Meritor Hub Grease, BlueLithium EP2 and refill the bearing cavity. Refer to table 3 for correctgrease quantities.
Note: Greased bearings should always be placed in a clean area.
3.10 REFIT INNER BEARINGRefit inner bearing cone into the inner bearing cup pressing fully hometo assist location of oil seal driver.
3.11 FIT NEW OIL SEALPress a NEW OIL SEAL onto the oil seal driver (Meritor part number21224749) ensuring the ‘OIL SIDE’ marking on the seal is visible (i.e.faces away from the plate of the driver) such that the seal will beinstalled the correct way round in the hub.
Locate the nose of the driver into the bore of the inner bearing coneand drive the seal fully home ensuring the seal remains square to thehub at all times (Fig. 6). The outer face of the seal should be flush withthe back face of the hub when fully installed.
Check the hub cavity grease and top up as necessary with Meritor HubGrease, Blue Lithium EP2. Refer to table 3 for correct grease quantity.
FIG. 5
FIG. 6
32
LM & LMC Service
3.12 REFIT OUTER BEARING AND RETAININGWASHERRefit the outer bearing cone. Fit the retaining washer into the hub,ensuring the adjustment indicator markings are facing outwards and fitthe retaining clip to hold the bearing cone in place ready for re-assembling hub to axle spindle (Fig. 7). Refer to Section 3 for refittingprocedure.
LM Hub Re-Fitment Procedure
3.13 CLEAN SPINDLE BEARING JOURNALPrior to re-assembling the hub onto the spindle, check the spindle fordamage and remove any fretting or rust on bearing journals usingmedium grade emery cloth strip. Also ensure the inner bearingabutment shoulder is clean and free from damage.
Clean the oil seal journal, removing brake dust or corrosion fromadjacent areas.
3.14 CHECK SPINDLE END THREADAny minor damage can be repaired using a M82 x 2 die nut and holder(Meritor part numbers 21224939 and 21224940).
Apply a thin, even coating of Optimol ‘Optimoly White Paste T’(available from Meritor Aftermarket Distributors) to the bearing journaland bearing abutment shoulder (Fig. 8).
This will reduce spindle wear and assist future removal of the hubassembly.
FIG. 7
3.15 RE-MOUNT HUB ASSEMBLYIf the hub is still assembled to the road wheel and brake drum, use awheel dolly to align the hub assembly with the axle spindle, adjustingthe height until the brake drum fits over the brake linings.
If the hub is to be replaced separately from the road wheel and brakedrum, ensure the hub is squarely aligned to the axle spindle duringrefitting.
Push the hub or hub, drum and wheel assembly onto the axle spindleand align the key on the retaining washer with the keyway in thespindle end. Push the assembly fully onto the spindle taking care not todamage the oil seal or spindle threads.
3.16 REFIT HUB LOCKNUTFit the hub locknut (Fig. 9) and tighten using hub nut spanner (Meritorpart number 21224839) until the nut is fully engaged on the spindlethread.
FIG. 8
FIG. 9
33
LM & LMC Service
3.17 HUB LOCKNUT SETTING PROCEDURE3.17.1 Torque the nut to 100 Nm WHILST ROTATING THE HUB. The hubMUST be rotated 5-10 revolutions whilst the end nut torque iscontinuously applied.
3.17.2 Back off the nut one flat of the socket (i.e. 1/8 turn) anti-clockwise.
3.17.3 Remove the hub nut spanner. Rotate the nut in a CLOCKWISEdirection (i.e. in the ‘tightening’ sense) until the corners of the nut alignwith the NEXT nearest mark on the face of the retaining washer (Fig. 10).
Should the corners of the nut already line up EXACTLY with an indexmark, do not further rotate the nut.
3.17.4 Fit the two button-head screws to the locknut and tighten evenlyuntil both the heads are flush with the face of the locknut.
Ensure the screws correctly engage into the holes in the lockwasher.
NOTE:From March 1998 the button-head screws include a nylon threadlocking patch. The locking properties of this patch are effective for twofurther applications of the screw after initial factory assembly. Thescrews should then be replaced.
3.17.5 Tighten the two button-head screws to the torque valuespecified in table 1 using a 5mm A/F Allen socket and torque wrench(Fig. 11).
NOTE: This torque value should be used for all screw types - i.e. with orwithout the nylon locking patch.
3.18 CHECK BEARING ADJUSTMENTCheck for free rotation of the hub assembly and ensure the bearingclearance is not excessive.
If in doubt repeat procedure 3.17.
3.19 REFIT HUB CAPCheck the seal location groove in the hub face is clean and fit the hubcap gasket (Fig. 12), engaging the raised rib of the gasket into thegroove in the hub face and align the hub cap bolt holes.
Fit the hub cap and tighten the bolts evenly. Finally tighten the hub capscrews to the torque value specified in table 1. Ensure the gasket iscompressed evenly and is not damaged (Fig. 13).
➡➡
FIG. 10
FIG. 11
FIG. 12
FIG. 13
Inspect brake shoes for wear at anchor pin and cam roller at locationpoint.
Prior to re-assembly the following parts should be lightly coated withROR high perfomance brake lubricant.
(i) Bores of Camshaft Bushes.(ii) Cam Rollers and camshaft head profile.(iii) Brake Anchor Pin bearing surfaces and holes in Brake Shoe
Gussets.
Ensure pressure greasing is carried out to the four grease nipples oneach axle. Use ROR high perfomance brake lubricant.
Check brake drums for cracks, scoring or other damage.
Replace all worn parts with genuine ROR parts. The use of non-OriginalROR parts will nullify all warranty and may substantially reduce servicelife.
14
TM Service
Major Brake Service
Braking can be divided into sub-systems each requiring maintenance toensure correct performance:
The Air SystemThe Foundation BrakesThe Brake ActuationThe Load Sensing/Anti-Lock System
The Air SystemSince April 1983 it has been a legal requirement to fit air pressure testpoints at the following points in the air system.
1) Each side of the load sensing valve.
2) The slowest brake actuator to respond when the brakes are applied.
In addition to these some trailer manufacturers fit a test point close tothe air reservoir.
With the aid of an air pressure test gauge (21214100) and connectinghose (21214101) the air pressure can be checked at the test points.
The air pressure, measured at the test point close to one of the brakechambers, should reach 6.5 to 7.5 bar with maximum application ofthe tractor brakes. If a load sensing valve is fitted it will be necessaryto either have the trailer loaded to capacity or disconnect the loadsensing valve linkage at the axle.
If the pressure reading is not reached then disconnect the trailer’syellow line and with a suitable coupling measure the air pressure at theyellow coupling. If there is ample pressure at this point the fault lies inthe trailer air system and must be traced and rectified.
The Foundation Brakes420mm, 350mm, 310mm.
The Brake Actuation
1.1 REMOVING BRAKE SHOES – SERIES IIIUsing a screwdriver between brake shoe gussets ease out both retainersprings (Fig. 1).
Take hold of bottom shoe pulling it off the anchor pin, tilt forward andlift off camshaft head (Fig. 2).
Remove brake return spring.
Lift off top shoe.
1.2 INSPECTIONInspect brake anchor pins and bushes for wear.
For Mark III anchor pins – check and replace ‘O’ rings as required.
Inspect cam rollers. If removed from the brake shoe, the roller-retainerclip must be replaced by a new unit.
SECTION 1
FIG. 1
FIG. 2
15
TM Service
1.3 RE-FITTING BRAKE SHOES 420MM & 350MMFit spring pins and rollers, lubricate ‘D’ holes with ROR highperfomance brake lubricant (Fig. 3).
Fit anchor pins applying ROR high perfomance brake lubricant insidethe anchor pin bushes (Fig. 4).
Fit top shoe and hang return spring from pin (Fig. 5).
Attach bottom shoe to spring, push down and in towards cam head,and onto anchor pin (Fig. 6).
Fit both retaining springs to top shoe, with screwdriver pull springdown and ease into bottom shoe (Fig. 7).
IMPORTANT: If anchor pin bushes require replacement, ArvinMeritor recommendsfitting the new bronze indented bushes 21016666A sealed anchor pinsNo. 21205193G and ‘O’ rings No. 21220668 (see page 20). The use oftool 21205456 is recommended as demonstrated in Fig. 8.
FIG. 7
FIG. 5
FIG. 3
FIG. 8
FIG. 6
FIG. 4
LUBRICATE
16
TM Service
1.4 RE-FITTING BRAKE SHOES 310MMFit spring pins and cam rollers, lubricate ‘D’ holes with ROR highperfomance brake lubricant.
Fit top shoe and hang return spring from pin (Fig. 9).
Attach bottom shoe to spring, push down and in towards cam head(Fig. 10).
Fit both retaining springs to both shoes (Fig. 11).
Lift top shoe and fit anchor pin.
Lever down bottom shoe and fit anchor pin – do not over stretchsprings (Fig. 12).FIG. 9
FIG. 10
FIG. 11
FIG. 12
18
TM Service
1.6 CAMSHAFT AND BUSHINGS1.6.1 REMOVAL
With brake shoes removed as described in previous section.
Remove slack adjuster.
Remove circlip adjacent to brake anchor bracket and withdrawcamshaft. The circlip will not be fully removable until the splined end isclear of the spherical bearing.
Inspect nylon bushes or bronze bush in the anchor bracket. Removebushes if worn.
Inspect spherical bearing for serviceability. This is a sealed assemblycontaining no user serviceable components.
Unscrew the securing bolts and remove the spherical bearing.
1.6.2 REPLACEMENT CAMSHAFTS
Stepped Camshafts
In use on production axles with 350 dia. brakes from October 1984 andaxles fitted with 420 and 394 dia. brakes from January 1985, thestepped camshaft is stiffer in torsion, making for improved brake timesand reduced air consumption, both very important under EEC/ECEbraking regulations, furthermore, it is fitted as standard with a thinwalled phosphor bronze bush in the anchor bracket, having superiorwear and temperature characteristics to the P.E.S. bushes used withearlier designs of camshafts.
On the earlier design of camshaft (Fig. 18) both the cam and sphericalbearing journals were the same diameter, with the shaft machined itsfull length. This camshaft was used in conjunction with two nylon cambushes or single bronze cambush having integral ‘O’ ring seals.
The cam journal has been increased in diameter on the latest ‘stepped’cam design (Fig. 19) specifically for use with a one piece phosphorbronze cam bush. In addition the camshaft now carries the ‘O’ ringseals (part number 21016721). This camshaft is not machined along itslength with one exception, camshafts for use with the 310 x 190 brakewhen used with Neway air suspension. The camshaft number suffixedwith an L or R for left and right hand is stamped into the shaft.
The new design can and should be used in preference to the earlierdesign when replacement becomes necessary. Only the phosphorbronze cam bush (part number 21209990) can be used with the newcamshaft, this bush replacing the two nylon bushes.
In order to fit stepped camshafts in axles as a replacement for theearlier design of camshaft it will be necessary to use the followingparts.
Camshaft bush kits containing these items are available.
Kit No. – AXL 1311⁄2 axle set suitable for T, U, TH and TM Axles pre May 1974.
Kit No. – AXL 1321⁄2 axle set suitable for TH and TM Axles after May 1974.
Fig. 20 shows the rolled spline camshaft used with 420mm brakes onaxles produced from 1st January 1992 it has the pressed steel anchorbraket with a bolt-on cam head spherical bearing.
This is identified by the snap ring groove in the centre of the cam headbearing journal.
Similar rolled spline camshafts without the snap ring groove wereintroduced on axles with 310mm and 350mm brakes.
FIG. 18
FIG. 19
FIG. 20
19
TM Service
REMOVAL OF THE 420mm CAMSHAFT
Having removed the slack adjuster the camshaft is released from thesnap ring by tapping the spline end with a suitable soft faced hammer.
It is necessary for the phosphor bronze bush to be a tight press fit intothe anchor bracket. Should the anchor bracket be worn (see Fig. 21) itwill be necessary to machine the cam bore to accommodate theoversize phosphor bronze cam bush (part number 21213259). If it isnecessary to fit oversize cam bushes the anchor bracket reamer toolshould be used and is available as follows:
Part Number Description
21206670/1 Cutter21206670/2 Shaft21206670/4 Sleeve21206670/5 Pins (two required)
21209271/1 Jig for 310mm diameter brakes21218572/1 Jig for 350mm diameter brakes21209272/1 Jig for 394mm diameter brakes21206670/3 Jig for 420mm diameter brakes
1.6.3 REFITTING
If it is necessary to replace the cam bushings, this can be easily doneusing special tool 21219919 (Fig. 22). Cam bush must be inserted fromcamhead side of anchor bracket.
ArvinMeritor recommends replacing the plastic bushes with phosphorbronze. These bushes are available in four sizes.
IMPORTANT:When fitting cam bush the cross holes must be towards the cam head,as shown (Fig. 23).
The camhead spherical bearing (Fig. 24) used on axles after June ‘91with the pressed steel anchor bracket applies to 420mm brakes only.Refit or replace bearing leaving bolts loose, fit the camshaft ensuringthe snap ring has locked into the groove in the bearing journal. Rotatethe camshaft to ensure free operation, tighten bearing bolts to thetorque specified in table 1 page 12.
FIG. 21
FIG. 23
FIG. 24
FIG. 22
21204703 – old type camshafts21209990 – new type “stepped” camshafts21209623 – oversize bush for old type camshaft bores
after reaming21213259 – oversize bush for stepped camshaft
PHOSPHOR BRONZE BUSHES
RECOMMENDED NOT RECOMMENDED
20
TM Service
Qty/Brake Part No. Qty/
Brake Part No. Qty/Brake Part No.
21016721
212027562120275799070011
2
111
21016721
210065932100662499070006
1
111
2101672021016721210065932100662499070006
22111
Cam Bush ‘O’ Ring
Cam Head WasherBevel WasherCirclip
Description
Refit or replace spherical bearing leaving bolts loose. ArvinMeritoroffers a new Mark III spherical bearing (Part No. 15213430) whichretains its grease pack and is more durable (Fig. 25).
Fit the ‘O’ rings onto the camshaft (with old type cam fit ‘O’ ring intobush). Slide the cam head washer onto the camshaft. Slide thecamshaft through the anchor bracket but not through the sphericalbearing at this stage. Fit bevel washer (concave side facing anchorbracket) and circlip onto the shaft. Slide the camshaft through thespherical bearing simultaneously pushing the bevel washer and circlipup to the anchor bracket. Ensure the circlip is fitted correctly into thegroove.
Rotate the cam to ensure correct alignment and free operation. Tightenthe spherical bearing bolts or Powerlok screws to 50-60 Nm (30 lbf ft).Rotate camshaft by hand to check that it moves freely. If it does notslacken spherical bearing bolts, realign camshaft and retighten bolts.Check again for free rotation. Grease pack the spherical bearingsthrough their grease nipples with Total Extemp or equivalent, untilgrease exudes from body.
1.7 SPRINGSThe return spring is an essential component for correct brake function.It should be examined for any relaxation in the coils or any wear ornotching in the hooks.
The retainer springs keep the shoes in contact with the anchorpins.They should also be inspected for any relaxation and hook damage.
IMPORTANT: It is strongly recommended that return and retainer springs arerenewed as a matter of course during annual brake servicing.
1.8 ANCHOR PINS AND BUSHESThe Mark III Axle has a sealed anchor pin system. The anchor pin hastwo oil and heat resistant ‘O’ rings as shown in Fig. 26 and is coatedwith Dacromet – a zinc rich coating with excellent corrosion resistance.The pin and ‘O’ rings are fitted into an indented bronze bush. Theindents are designed to hold additional grease to lubricate the anchorpin over an extended period. An additional benefit is the ease ofremoving anchor pins whenever a major overhaul is carried out.
The sealed anchor pins and indented bushes are available in kit formfrom your ArvinMeritor Stockist and are interchangeable with earlierdesigns of anchor pin bushes used with quick change brake shoes.
Qty/Brake Description Part Number2 Anchor Pin 21205193G4 ‘O’ Ring 212206682 Bush 21016666A
From June ‘91 axles with 420mm brake have a pressed steel anchorbracket which uses a stainless steel bush part number 21221028.
1.9 RELINING BRAKE SHOESIt is recommended that the correct lining be used to maintain the EECperformance levels designed and approved for your vehicle. A changein lining may substantially change the braking performance and couldrender the vehicle illegal. ROR linings are precisely contoured to fit RORshoes and “bed-in” with the least number of stops.
The ROR shoe is coated with a rust inhibiting paint. When relining theshoe platform should be cleaned and recoated with a rust-proof primer.The hardened anchor pin and cam roller location points must beinspected for damage. Renew shoe if these areas are damaged.
FIG. 25
FIG. 26
Part numbers for various components to suit the different camshafts are given in the following table.
OLD CAMSHAFTPlastic Cam Bushes Bronze Bush
NEW STEPPEDCAMSHAFT
21
TM Service
The ROR patented series III shoe is capable of many relines. Makecertain your stockist is giving you genuine ROR shoes when youexchange the original shoes. Look for the ROR logo and patent numberon every shoe gusset.
1.10 BRAKE DRUMSIf, upon inspection, drums are crazed and cracked it is an indicationthat the brake has been running excessively hot. Fitting new drums willnot correct the cause of the problem. The following list are possiblecauses:
a. The towing vehicle is fitted with a predominance valve andit is set to make the trailer brakes do most of the checkbraking.
b. Badly set or malfunctioning automatic slack adjuster.
c. Use of trailer brakes ONLY to check vehicle speed duringlong descents.
d. The use of a non approved lining.
e. Malfunction in air actuation system (see following Section).
In all cases the use of pressure test gauges at each test point willenable you to ascertain what is happening.
Light crazing of the braking surface indicates that the drum has beenoverheated but does not render the drum unserviceable. Howeverbrake drums with any other damage e.g. rivet grooving, must berectified or replaced immediately.
Re-machining of drums is permissible if surface damage is slight withthe exception of the 310mm brake drum which must always bereplaced. The maximum bore diameters that the drums can bemachined to are:
420 – 423mm350 – 354mm310 – No re-machining.
Oversize cam rollers (21006610A) must be used in conjunction with re-machined drums.
Drums should be clean and dry before refitting. Care should be takenwith loose dust as stated in The Garage Workers’ Asbestos Code (Page45). Replacement brake drums from ArvinMeritor are supplied with aprotective coating that does not need removing before fitting.
1.11 DUST COVERSDust Covers are provided with inspection apertures to assess liningwear. These apertures are closed with rubber plugs which must alwaysbe replaced.
Pre June 91 Dust Covers are fixed with six M8 x 1.25 tightened to thetorque specified in table 1 page 12. If additional sealing is required –ArvinMeritor offers an optional rubber sealing kit (Fig. 27).
Included:
1. U-Shaped moulded sealing strip to close the Dust Cover around theCam end of the Anchor Bracket.
2. Rubber Collar to close the end of the Camshaft bush (retained with acable tie).
3. Outer rubber collar to close the Spherical bearing assembly(retained with a cable tie).
4. Inner rubber collar to close the Spherical bearing assembly (retainedby the Slack Adjuster).
From June ‘91 axles fitted with pressed steel anchor brackets, 420mmbrakes only, have dust covers retained by four M10 screws tightened tothe torque specified in table 1, page 12.
From August ’97 TM Series axles with 420 diameter brakes are fittedwith the “LM style” dust cover.
To refit with the camshaft removed: Ensure the filler plate locating tagis engaged around the end of the anchor bracket and secure with twoM10 screws. Tighten to the torque specified in table 1, page 12.
Fit the one piece dust cover ensuring it is correctly located onto the twofiller plate studs. Tighten the two M10 screws and the two M8 nuts tothe torque values specified in table 1, page 12.
If the camshaft is to be refitted prior to the dust cover: Clean the fulllength of the camshaft prior to assembly. Slide the under-head rubberboot onto the camshaft, lightly grease the cam head journal and slidethe cam head bearing onto the camshaft towards the cam head untilthe spring clip is ready to engage in the groove (light resistance will befelt).
Slide the inner rubber boots, cover plate and spline end sphericalbearing onto the camshaft.
Ensure the faces of the anchor bracket and camshaft bracket are clean.
Pass the cam head through the key hole slot in the brake anchorbracket and slide the spline end through the cam bracket slot. Fastenboth camshaft bearings in position using the M10 screws. DO NOTFULLY TIGHTEN THE BEARING SECURING SCREWS UNTIL THE BRAKESHOES ARE RE-ASSEMBLED.
Ensure the filler plate locating tag is engaged around the end of theanchor bracket and secure with two M10 screws. Tighten to the torquespecified in table 1, page 12.
Fit the one piece dust cover ensuring it is correctly located onto the twofiller plate studs. Tighten the two M10 screws and the two M8 nuts tothe torque values specified in table 1, page 12.
FIG. 27
42
TM Service
FIG. 1
FIG. 2
Additional Procedures
5.1 WHEEL FIXINGSCurrently there are three different types of wheel mounting in commonuse:
• British Standard system using 7⁄8” BSF thread and 80º conical seatings, (usually with L.H. and R.H. threads)
• DIN metric system with M22 threads and spherical seatings• ISO system again using M22 threads but locates the wheels by the
centre bore on a spigot on the hub.
It is imperative that trailer manufacturers and operators ensure that thewheels and wheel mountings on the axle are compatible beforeassembling wheels to the axles and tightening to the recommendedtorque settings.
The achievable clamp load can vary considerably for a given appliedtorque depending upon a member of variable factors such as thesurface condition of the bolts and nut threads.
To ensure accurate and positive location of the wheel, all matingsurfaces should be free from dirt, excessive paint, rust and damage.
The only satisfactory method of maintaining the correct torque figures,which are based on coated and lightly oiled threads, is by using acorrectly calibrated torque wrench.
All ROR axles with DIN and ISO fixings have RIGHT HAND THREADEDBOLTS ON BOTH SIDES OF THE AXLES. Adhesive labels are available tohighlight this.
If inspection reveals damage to bolts, cones or wheels, replacement isrecommended. THIS CONDITION IS USUALLY DIRECTLY RELATED TOIMPROPER TIGHTENING.
The wheel bolt – being a safety critical component – should only bereplaced with ORIGINAL ROR PARTS.
5.2 REMOVAL AND REFITTING OF WHEEL BOLTS(REFER TO WHEEL BOLT CHART FIG. 3)ROR bolts are pressed into the hub and drum assembly and retained byserrations and the press fit in the hub.
Damage to wheelbolts is caused by:-
• Loose wheel nuts• Over tightened wheel nuts• Mismatched wheel and fixings• Cross threadings• Mismatched bolts and nuts
To remove – They should be carefully pressed or hammered out usingthe wheel bolt removal tool (ROR Part No. 21205455) (Fig. 1).
IMPORTANT:ALL MATING SURFACES SHOULD BE CLEAN, DRY AND FREE OF BURRSPRIOR TO REASSEMBLY.
SECTION 4 To replace – Care should be taken to align the serrations of bolt andhub. They must be driven FULLY home with the wheel bolt driving tool(ROR Part No. 21211274) (Fig. 2), using the sequence as for wheel nuttightening. Ensure no gap exists between hub, drum and wheelbolthead. When fitted the anti-lock Exciter Ring is retained by the wheelbolts. When driving the wheel bolts home great care should be takennot to damage the Exciter Ring.
43
TM Service
Nut – 21016416/7Bolt – 21020735/6
Nut – 21226395Bolt – 21020997
Bolts R.H. 21211162L.H. 21211163
Nut – 21016416/7Bolt – 21018490/1Cone – 21201588
Nut – 21226395Bolt – 21206355
For Steel & Alloy Wheels – 21226397
Wheel Fixing SystemsFIG. 3
Type
B.S.F.7/8”550/600 Nm400/450 lbf ft
DIN550/600 Nm400/450 lbf ft
ISO700/750 Nm500/550 lbf ft
Alloy Wheels(ISO)700/750 Nm500/550 lbf ft
Single Wheel Twin Wheels
Japanese (Twin Metric)Optional “Clean Thread”
Closed End Nut (M22 x 1.5)
Nut – 21006511Bolt – 21022167Cone – 21006512
Nut – 21006511Bolt – 21020997
Outer Cone – 21006512Inner Cone – 21019026
Nut – 21226395Bolt – 21022167
Nut – 21226395Bolt – 21020997
44
TM Service
5.3 THE BRAKE ACTUATIONThis includes the correct attachment of the brake chamber or springbrake; the correct connection of the push rod to the slack adjuster(either manual or automatic); and the setting and adjustment of theslack adjuster.
5.3.1 AIR CHAMBER BRACKET ATTACHMENT
ArvinMeritor welds its air chamber brackets at the angles shown in Fig. 4 to give the optimum air chamber installation with the slackadjuster length shown: any deviation from this may detract from theoptimum brake performance. To check the angle use a combinationprotractor and level gauge. Measure the edge of the cam braket andthe face of the air chamber bracket as shown in Fig. 4 and add the twoangles.
5.3.2 AIR CHAMBER TO SLACK ADJUSTER(Manual Slack Adjusters)
Position the air chamber in place on the mounting bracket, ensuring thecorrect hole pairing on the bracket is used corresponding to the slackadjuster lever length being fitted (see Fig. 5). Secure the air chamber tothe air chamber mounting bracket using the mounting provided toensure the chamber does not move during the setting up procedureand tighten to a torque of 120-130 Nm (85-95 lbf ft).
Fit the slack adjuster to the camshaft applying Total Extemp orequivalent grease to the spline. Connect pushrod clevis to slackadjuster assembly. Optimum braking is achieved when the anglebetween the pushrod and slack adjuster arm is 90º with the brakesapplied.
ArvinMeritor do not recommend the use of a sliding clevis. If one isfitted it will be necessary to fit a pull-off spring between the slackadjuster and the air chamber bracket (Part No. 21210215).
5.4 FITTING OF HUBODOMETERThe TM axle may be fitted with an hubodometer by using a special hubcap. It is not possible to fit an hubodometer to a standard hub cap andattempting to do so will affect the hub sealing and may damage thespindle.
For hubodometer types up to 85mm outside diameter use hub capMeritor Part No. 21224904.
It is advisable to assemble the hubodometer to the hub cap prior tofitting the hub cap to the axle. Place the hub cap on a clean, flatsurface. Fit the nut to a suitable open ended spanner and using a smallamount of grease place the washer onto the nut.
Using the spanner, position the nut and washer under the mountinghole in the cross bar of the hub cap. Lower the hubodometer throughthe hole to engage the thread. Rotate the hubodometer to screw thenut along the mounting stud until hand tight. Finally tighten the nut withthe spanner in the normal way (Fig. 6).
The hub cap and gasket can now be fitted to the axle as described inSection 3.
FIG. 4
Brake Angle Slack Adjuster InstalledSize ‘A’ Lengths Length*
420 107º 127, 140 & 152mm 185mm(5, 51⁄2, 6in)
350 110º 127, 140 & 152mm 165mm(5, 51⁄2, 6in)
310 95º 127 to 152mm 195mm(5 to 6in)
*Note: Installed length is the distance between the clevis pin centre andthe mounting face of the air chamber with the brakes released.
FIG. 5
AIR CHAMBERMOUNTINGBRACKET
ANGLE ‘Y’
CAM BRACKET
ANGLE ‘X’
ANGLE X + Y = ANGLE A(SEE TABLE)
A-B 152mm LEVER
A-C 140mm LEVER
A-D 127mm LEVER
420/350mm 310mm
AIR CHAMBER FITTING HOLES IN BRACKET
FIG. 6
45
TM Service
5.5 GARAGE WORKERS’ ASBESTOS CODE1. DON’T blow dust out of brake drums or clutch housings with an air
line.
2. DO use properly designed drum cleaning equipment which preventsdust escaping,oruse clean wet rags to clean out drums or housings. Put used rags ina plastic waste bag while still wet.
3. DON’T grind or drill linings unless the machine has exhaustventilation or there is a ventilated booth to do the work in.
4. DON’T use brushes to sweep up dust.
5. DO use a special (Type H) vacuum cleaner to remove dust.
6. DO wet dust thoroughly and scrape it up if you haven’t got avacuum.
7. DO wear the protective clothing, such as overalls, provided by youremployer.
8. DON’T take the protective clothing home. It should be cleaned byyour employer.
9. DON’T use equipment if it is not maintained and checked. Ask tosee the examination reports for ventilation systems.
