W3A 040 transmission questions
 

3-speed auto with torque converter (vs. hydraulic clutch) as in my 1973 450SE: purportedly very rugged in both design and service?

Other than the normal Mercedes-type tranny service with filter and drain of the torque converter, is there anything else I should be aware of or do to keep it running? Seems to me that it shifts pretty darn good, nice and smooth, no slippage I can detect.

Is it worth going to a synthetic tranny fluid or will a conventional DEXRON III/MERCON suffice?

:confused:

That is a very robust tranny, not usually any trouble with it. It was designed to hold up to the 6.3L M100 engine, so you shouldn't worry too much about abusing it.

Synthetic tranny fluid should extend the life.

Peter

I concur. The only down side to that tranny is having time to eat a burger before it goes into reverse, but the that's not a biggie.

Peter

I know this thread is super old but for anybody reading, the 6.3 and the 600 both have a K4B 050 4 speed trans. 050 is the torque rating, meaning that it is stouter than the other xxx025 and xxx040 transes.

Indeed. For interest sake, the 6.9 uses the 3 speed trans, beefed up to handle all that torque! It is unique to the 6.9 model, 722.003, designation W3B 050.

The W3B 050 was also used with engine M117.960 in the 500 SLC, it was designated 722.006. The difference is in the convertor housings to match the two engines.