Ever heard of Miesbach??

This small town of only around 12,000 inhabitants near the Austrian border is not only considered to be a centre of Bavarian traditional customs. It is also one of the highest-altitude towns in Germany (around 700 m above sea level). And this is probably also no small reason why the district bearing the same name is also the leader in terms of the proportion of cars with four-wheel drive (28.3% compared to a national average of 12.8%). This can hardly come as a surprise, since a four-wheel drive offers better traction and thereby greater handling and stability when driving in adverse weather conditions, as well as boasting better off-road capabilities.

A key component of many vehicles with four-wheel drive is the multi-plate clutch, which runs in an oil bath. It has the task of directing the drive force to the rear axle, which is normally not driven, when the slip becomes too great during pure front-wheel driving. This is regulated by the actuation of the electrohydraulic oil pump, which ensures that the torque on the rear axle increases by increasing the contact pressure on the clutch plates.

The inevitable abrasion that occurs is absorbed by the oil, which is why the clutch must be serviced and the oil changed at regular intervals. If this is not done or done too late, the contaminations can cause problems. Of course, the housing of the oil pump can also corrode over time due to external influences.

So, don’t wait for the pump to fail and cripple the four-wheel drive: AIC currently stocks 19 oil pumps/disc clutches for 948 applications.

Incidentally: If your rear axle transmission/haldex clutch is equipped with a hydraulic filter, this should also be replaced regularly. This applies, for example, to Volvo vehicles, where we already have the right solution in our range with item no. 57986.