A differential is a piece of stuff located in the drivetrain of Mercedes. It plays a pivotal role in maintaining the balance during the turns. So many factors are there that contribute to a differentia leak. A leaking gasket, a leaking pinion seal, or a leaking differential side seal- can be the cause for a leak in the differential. Ignoring the rear differential leak can be damaging. So, if you have a failing differential, then you should service it by removing the cover, replacing the old fluid with clean fluid, and resealing the cover.