To start, have you checked the differential fluid level? You can pull out the rubber stopper and the level should be at the height of the bottom of the hole or down slightly assuming you have a slow leak. The rubber plug is part way up the back of the differential cover facing the back of the vehicle. If there is no fluid left in the differential, then the problem could be more significant than just a cover replacement.
We have a 2008 Sprinter 3500 with the
Agile upgraded differential cover.
You can either bend your cover back and install a new gasket or install the Agile cover. You can get a new gasket from a dealer using your VIN if you fix your current cover or the Agile cover includes a new one.
On the Agile website it says it is for Sprinter 2015+. For our 2008 Sprinter 3500 we had to drill out the Agile cover bolt holes slightly and replace the bolts because the factory bolt heads were too large to fit in the cover. We used these
bolts from McMaster and they fit really well. The gasket holes also had to be slightly enlarged. I am not sure if this will be the same for your 2500.
The Agile
instructions mention 16ft-lbs for the bolts and also to use blue Loctite. Either way I would highly recommend the Loctite because we did have these bolts loosen up once before adding the thread locker.
We originally got the upgraded cover because we were driving on dirt roads a fair amount. Rumor has it that people have also damaged the differential cover when a rock hits it causing a similar bend to what the tire shop did with a jack. The upgarded cover solves this issue because it is thicker and does not hang below the body of the differential. It is a flush cover.
Also, we used their heavy duty
gear oil with good results so far. It is a little thicker viscosity than stock fluid.
