2013-11-22 ENG Version 05

Rear axleRTS2370AFact Sheet

The RTS2370A is a tandem axle with single reduction, hypoid gears, designed for an engine torque of 3550 Nm. The maximum axle weight and combined vehicle weight are 23 and 70 tonnes respectively.

The RTS2370A is a tandem axle consisting of two, single reduction hypoid gears, and a transfer gear located in the forward axle. The rear axle casings are cast in nodular iron, which results in a compact design and high ground clear-ance. This rear axle combination is intended for heavy and demanding types of transport in both good and difficult road conditions. Drive from two axles provides very high driving force since the total axle weight is high. This results in excellent tractive force and low tyre wear. The RTS2370A is fitted with three differential locks; one each for the forward and rear axles in the tandem pair, and one for the transfer gear. This guarantees very good tractive force on slippery surfaces, thereby increasing vehicle productivity. The differential locks are easily regulated with a two-step

switch on the instrument panel. When the switches’ first step is engaged, the differential lock for the transfer gear is activated, which couples both of the rear axles together. Using the switches’ second step locks the drive shafts of the respective rear axles together.New design solutions and production methods have re-sulted in a rear axle with an extremely long service life. The rear axle also has long service intervals, which contribute to low operating costs. If approved synthetic oil is used, the oil change interval is after a maximum of 450,000 km or every third year. The following product features characterise the RT-S2370A:• Two single reduction, hypoid gears with great strength

and quiet operation.• Heavy-duty, hardened shafts and gears.• Three reliable differential locks, for high vehicle availa-

bility. • Unit, maintenance-free bearings for longer service life

and easier service.

Specifications

Designation .............................................................RTS2370AType:Rear axle ........................................... Single reduction, hypoidTransfer gear ...........................................Cylindrical spur gearWeight including drive shafts, hubs, drum brakes (when fitted with leaf springs):Forward axle ...................................................................806 kgRear axle ..........................................................................680 kgWeight including drive shafts, hubs, disc brakes (when fitted with leaf springs):Forward axle ...................................................................763 kgRear axle ..........................................................................663 kgWeight including drive shafts, hubs, disc brakes (when fitted with air suspension):Forward axle ...................................................................753 kgRear axle ..........................................................................640 kgCrown wheel, diameter .....................................401-417 mmDrive shafts, diameter ....................................................53 mmMaximum engine torque ......................................... 3550 Nm

Max. axle load ............................................................23000 kgMax. gross combination weight ............................70000 kgRatios:Rear axle ...........................................................................2.43:1............................................................................................2.57:1............................................................................................2.83:1............................................................................................3.09:1............................................................................................3.40:1............................................................................................3.78:1............................................................................................ 4.13:1............................................................................................4.50:1............................................................................................ 5.14:1............................................................................................5.67:1............................................................................................6.17:1Transfer gear ...........................................................................1:1Oil volume:Forward axle ......................................................................... 20 lRear axle .................................................................................14 l

Rear axleRTS2370AFact Sheet

Tandem drive for excellent driving force and tractive force

The RTS2370A consists of two single reduction, hypoid gears, and a transfer gear that is built into the forward rear axle.The function of the transfer gear is to distribute power evenly between both of the rear axles.Drive from the gearbox goes via the transfer gear’s input shaft to the dif-ferential. From the differential, drive is transferred, partly via a cylindrical spur gear to the forward rear axle’s final drive, and partly to the transfer gear’s output shaft, which drives the rear axle’s final drive via a propshaft.This type of rear axle combination with tandem drive means that a great deal of power can be transferred to the road surface since the combined axle weight is high. This results in good tractive force and low tyre wear.

Three differential locks provide high availability

The RTS2370A is fitted with three dif-ferential locks, one for each of the rear axles, and one for the transfer gear. The transfer gear’s differential lock couples drive to both of the rear axles, while the differential locks in each of the rear axles lock the respective axles’ drive shafts to their final drives. When all of the dif-ferential locks are engaged, this forces all of the wheels to rotate at the same speed. The differential locks consist of hardened steel, toothed couplings that are operated by compressed air. Two lamps in the instrument panel indicate that the differential locks are engaged. One lamp is for the transfer gear’s differential lock, and the other one indicates that the differential locks in both rear axles are engaged.The function of the differential locks guarantees very good tractive force on slippery surfaces, which results in high vehicle availability.

Hypoid rear axle for quiet operation and high reliability

On a hypoid rear axle, the pinion gear’s centre line is offset in relation to the centre of the crown wheel. This design enables a large diameter pinion and a greater number of teeth to be in mesh simultaneously. This results in quiet operation and high reliability. The crown wheel has diameters of 401-417 mm, depending on the gear ratio.The pinion has “pinion pack” journaling, which means that the pinion is journalled with two closely fitted conical roller bear-ings in front of the pinion gear.

Unit bearings for increased service life and easier service

The wheel bearings are designed as maintenance-free unit bearings. The bearing installation consists of coni-cal roller bearings, which are perma-nently lubricated from the factory and equipped with efficient seals. The wheel hub with bearings is fitted and removed as a unit, which facilitates service and maintenance work. It is not necessary to adjust bearing play.

Single reduction in the forward rear axle

Transfer gear in the forward rear axle Differential lock engaged (rear axle)

Differential lock disengaged (rear axle)