Modular gearboxes and axle gears for 220 to 530 hp
Scania's current gearbox generation was launched in 1991. Three gearboxes are carried over from the 3-series and one is new. Final drive options include several single-reduction and hub-reduction axles and bogies with different weight ratings. Unique to Scania are the Scania Retarder and Scania Opticruise.
Scania’s gearbox range consists of two range-change gearboxes and two range-splitter units. One in each category is provided with crawler ratios:
- GR801 – 8-speed range-change gearbox for 220-310 hp
- GRS890 – 12-speed range-splitter for 260-340 hp
- GR900 – 8+1-speed range-change gearbox (one crawler) for 220-400 hp
- GRS900 – 12+2-speed range-splitter (two crawlers) for 310-530 hp
There is a free choice of gearbox within the above power ranges.
Scania Retarder – available in all segmentsThe familiar Scania Retarder is available as an option on all gearboxes except the GR801. Unveiled at the Brussels show in 1993, the hydrodynamic retarder is designed and produced in-house by Scania. The retarder is integrated in the gearbox and has compact dimensions and low weight, compared to retrofit alternatives. Cooling is via the engine’s cooling system.
The system interacts with other control systems on the vehicle, including EDC, exhaust brake, ABS and TC (traction control), if fitted. A downhill speed control function allows a constant speed to be maintained automatically.
The retarder produces approximately 500 kW, and the exhaust brake on the 14-litre engine close to 200 kW, both figures at 2,000 r/min engine speed. Retarder output is automatically optimised in relation to the coolant temperature, which means that the retarder is most efficient at high road speed. The exhaust brake on the other hand is most efficient at low speed (below 40 km/h). The high output of the retarder means that the wheel brakes are normally only employed in 25% of brake applications.
An in-house developed powertrain management system, Opticruise has been subjected to large-scale operational tests since 1993 and comprehensive field tests with customers since 1994. Opticruise is now an option on L- and G-class vehicles with EDC engines, i.e. outputs above 400 hp.
The system provides integrated control of engine, gearbox and retarder, combined with fully automatic up- and downchanges. The clutch is operated by the driver for starting and stopping and neither clutch nor synchromesh are used by the system. Operation is intuitive and easy to learn and manual override is possible, also with the gear selector in automatic mode.
Smooth all-wheel-drive in C-class
All-wheel-drive (4x4, 6x6) vehicles all have the 12-speed GRS890 range-splitter gearbox. Crawlers are not needed on these vehicles since they are equipped with a 2-speed transfer box giving extra-low ratios.
The transfer box on all-wheel-drive vehicles is available in two strengths: GTD800 for 4x4 vehicles and 6x6 with 21-tonne bogie weight, and GTD900 for 6x6 with 26-tonne bogie. Both are 2-speed with a road ratio of 0.89:1 and an off-road ratio of 1.536:1.
The V-shaped chassis frame used on the 4-series permits the whole powertrain to be mounted lower in the chassis. Universal-joint angles are therefore improved compared to previous all-wheel-drive models, giving smooth and even power transmission with less strain and wind-up on both front and rear axles.
The driven front axle is an in-house Scania design featuring hub reduction and generous ground clearance. It is designed for front axle weights up to 9000 kg and the gear ratios allow it to be combined with several other axle gears.
Four rear axles, three tandem bogies
Depending on application and weight, the rear axle or bogie is either of the single-reduction or hub-reduction type. Scania rear axles have been up-rated in recent years to cope with the reverse torque involved in retarder braking.
Single-reduction rear axle R560 (up to 28 tonnes) new
Single-reduction rear axle R660 (up to 40 tonnes) new
Single-reduction rear axle R780 (up to 70 tonnes)
Hub-reduction rear axle RP832 (up to 80 tonnes)
Driven hub-reduction front axle RP731 (front axle weight up to 9 tonnes)
Single-reduction tandem bogie RB660 + R660 (up to 78 tonnes)
Hub-reduction tandem bogie RBP730 + RP730 (up to 100 tonnes)
Hub-reduction tandem bogie RBP832 + RP832 with hub reduction
(up to 150 tonnes)
R560 is available for 9-litre engines (220 and 260 hp) in the D-class. R660 can be specified with 9-litre engines in all classes and with 11- and 12-litre engines up to 360 hp in the L-class. R780 is available across the range, with the exception of the D-class. RP832 with hub reduction for increased mobility and strength is available in the C- and G-classes.
The RB660 + R660 light tandem bogie is available for all outputs in the L- and G-class and up to 400 hp in the C-class. Its hub-reduction counterpart RBP730 + RP730 is optional in the C- and G-classes from 260 hp. The heaviest RBP832 + RP832 hub-reduction bogie is available in the C- and G-classes.
A wide range of power take-offs caters for the needs of every application. The PTOs are driven either by the engine’s timing gears, the flywheel or the gearbox. Drive is either direct or via a propeller shaft. Scania’s power take-offs are also available with several mounting positions.