Just about all BMWs are now being engineered with a sunken nut input flange on the differential. (See picture) Unfortunately, the seals behind this are becoming commonplace to leak. This configuration requires special tooling in order to successfully replace the seals without damaging the input shaft bearing.

The first step requires the removal of the propshaft from the input flange.

Once this is done, the input flange can be removed from the differential.

Doing this gains access to the input shaft seal. This can then be removed and replaced using special tools.

Once this has been replaced, the input flange can be refitted after applying a specific grease to the flange recesses. A new nut with microencapsulation is used to secure the propshaft to the input flange.

Munich Power are very well practised at these repairs.

Due to the specialist equipment required very few workshops are able to carry out these repairs.

Please get in touch if you’re suffering from oil loss from your differential.