I am currently doing my 100K tuneup stuff on my 2001 ML430 with 111K miles on it and was wondering if I should change out the differential oils or not. Do any of you change yours as part of routine maintenance? I changed the rear oil in my 1996 C220 this past summer with Lucas synthetic gear oil as it had about 140K on it and I figured with it being rear wheel drive it was probably due (and it was pretty dirty looking when it came out), but not sure about the ML since it is both newer and all wheel drive. Does the rear differential use synthetic gear oil while the front one use transmission fluid or do they both use gear oil or both use transmission fluid? I know, I know...get out my owner's manual and read... Just thought I'd get everyone else's opinion on if you change yours or not and if so what do you use.
Cool. Thanks. I changed the rear today with Lucas synthetic hypoid as there was no real general consensus on what brand was best and Lucas has been good to me in the past with MB (and it's more expensive than Mobile 1 and Amsoil). Still need to do the front but that will involve jacking it up and dropping the shield and I've done enough today with the rear differential and a total coolant flush and refill. Maybe tomorrow.