Originally Posted by M.B.DOC

There have been 2 MB 5 speed auto transmissions here in the USA. The first one was the 722.3 modified with an overdrive unit. That was only used HERE in the 1990-98 M104 engine R129 SL's & the 1992-99 300SE/S320's W140 cars.

The later 722.6 5 speed came to the USA in 1996 in V-8/12 cars & then ALL MB's from 1997, of course many V-8 2004/05 models can get the new 722.9 7-speed auto trans.

The biggest downfall of the 722.6 trans in your C36 is the lack of recommended fluid changes! The most common failure on pre-99 models is the rear plantary. MB used a bushing then & now uses a needle-bearing as a replacement on all but the 4-cyl versions.
IF you want a long lasting trans then service it at least every 30-50K miles, life-time fluids are a LAUGH in the real world! Servicing the 722.6 should run $250 +- a few $$$
A well maintained auto trans SHOULD last 200K-300K miles! But many don't!