E320 1998 Differential leaks
Mercedes wanted $65 a liter for there product. I didn't quite fill the differential , left room for 200mm (just under 8 ounces). I filled the rest of the differential with Gunk Transmission Fluid Treatment with the intention of it softening the seals and resolving my leak. I cleaned off the undercarriage and differential casing and will check in a few weeks for further loss of fluid. If the leaking has resolved I then plan to drain the fluid again and add Mobil Synthetic Gear Lube..$15 a liter (quart). I'll keep you posted. I will add that my leak looked quite bad but when I drained out the fluid it measures 1 litre, so I had only lost 200-300 mm.



