Please educate me on tranny vs diff: C4S

[GOB]

I know my car has only one transmission (where gears are) and that requires ATF fluid and to be changed as described on another post I recently wrote about, but where I'm getting a bit confused is on the differentials.

There is a diff in the front axle of my car, but is there a diff in the rear too? Do diffs use a different liquid/fluid/oil than the tranny (+02 cars are very specific with regards to ATF to be used on the Mercedes built boxes). Do I need to change out the fluids in the diffs too if I do the ATF tranny flush/filter replacement? Any DIY on this?

Please forgive my ignorance on the matter :blush:

Edited October 10, 2013 by GOB

[JFP in PA]

I know my car has only one transmission (where gears are) and that requires ATF fluid and to be changed as described on another post I recently wrote about, but where I'm getting a bit confused is on the differentials.

There is a diff in the front axle of my car, but is there a diff in the rear too? Do diffs use a different liquid/fluid/oil than the tranny (+02 cars are very specific with regards to ATF to be used on the Mercedes built boxes). Do I need to change out the fluids in the diffs too if I do the ATF tranny flush/filter replacement? Any DIY on this?

Please forgive my ignorance on the matter :blush:

You have separate front and rear differentials in addition to the Tiptronic trans. Because yours is an 02, you have the benefit of both a fill and drain plug on the re diff, something the earlier cars lacked, making fluid changes a bit of a pain. Your rear diff uses and 85W90 hypoid gear oil, while the front diff uses 75W90.

If I can make a suggestion, invest in the Bentley manual for your car, it contains copious information and photos on these service items and could save you a lot of money in the long run, and you can get it at the RennTech store link under the "Special Offers" tab at the top of this page.

[creekman]

GOB, Also there's some very useful information on oil changes, light bulb replacement to be found on this site... go to:

1. DIY Tutorials

2. Carrera 996

3. Then scroll down for specific information.