As part of ongoing technical developments the following modifications have been carried out on rear axle 746.21 (HO 6):
As from rear axle no. M133838 a new, modified differential is installed in the previous axle housing.
On all axles with modified differential only oil in accordance with the MB Specifications for Operating Fluids 235.20 (EvoBus 35.000-001) may be used.
The modified differential is a sealed differential, i.e. the toothed gears of the differential are sealed by a metal construction. Lubrication is performed by a separate oil supply,which is located inside the encapsulation.
It is not a complete encapsulation, therefore a small exchange still takes place between the oil supply in the axle housing and the oil supply in the differential.
The previous differential was designed as an open differential, i.e. the differential's toothed gears are directly wetted or lubricated using the oil spray.
The differential assembly with sealed differential is only supplied as a replacement part.
Installation notes
Before installing the differential assembly with sealed differential in the axle housing, 0.5 l of oil must be poured into the differential, otherwise the gears of the differential will not be lubricated and the entire differential assembly will be irreparably damaged. Each filling quantity for the respective axles remains unchanged.