Oil Supply For 4Matic Transfer Case Function - GF28.55-P-3010AVO
Model 257.361, 290
up to model year 2021
View of transfer case, shown on vehicles with engine 177.9
View of transmission housing
View of transmission housing
Function requirements for 4MATIC transfer case oil supply, general
- Vehicle is moving or rolling.
Oil supply for 4MATIC transfer case, general
The oil supply system ensures that the components of the transfer case are sufficiently greased and cooled.
The flange-mounted construction means that the transfer case and automatic transmission have a separate oil system The following oil reservoirs are present in the transfer case:
- Front axle transmission output compartment and pump intake compartment (A)
- Tank compartment (B)
- Oil supply reservoir (settled) (C)
Tank compartment (B) and the front axle transmission output compartment and pump intake compartment (A) are connected to each other via oil holes When the vehicle is stationary the oil level is identical in both of these compartments
Function sequence for 4MATIC transfer case oil supply
The oil pump is housed on the outside of the transfer case housing and is driven by the front axle transmission output.
It delivers the oil from the lower area in the rear section of the housing upwards through an oil duct. The oil flows from above into the transfer case, lubricates and cools all moving parts and gathers at the bottom again.
Transfer case with engine 256
Oil cooling
The transfer cases of the vehicles with engine 256 are cooled passively whilst vehicles with engine 177.9 are cooled actively by means of a transmission oil heat exchanger.
The oil from the pump intake compartment is delivered via the oil pump to the transmission oil heat exchanger, cooled, and delivered into the front axle transmission output compartment and the pump intake compartment via the inlet from the transmission oil heat exchanger and via the connection between the front axle transmission output compartment and pump intake compartment. The tank compartment connection enables the oil to flow into the fluid reservoir (killed) and on to the oil inlet for the multiplate clutch where it cools the multiplate clutch.
View of multiplate clutch oil supply (example)
The oil flow to the multidisk clutch is controlled by the cover (3). The oil is directed through the open cover (3) and flows to the multidisk clutch so that this is cooled.
| Overview of system components, automatically controlled all-wheel drive (4MATIC) | GF28.00-P-9998AVO |