I have an 81 SL with 163K miles. It has three shifter positions (L,S,D) but shifts four (4) times from dead start. Purchased the car with 65K miles and it has always shifted very quickley from 1st to 2nd and rarely kicks down to 2nd after deceleration unless almost to a crawl. For instance, when turning onto a secondary street it normally only downshifts to 3rd. Additionally sometimes shifts hard from 2nd to 3rd on quick acceleration. I have recently experienced shuttering and slipping in reverse that is typically more noticeable when hot.

I would appreciate any advice or suggestions for resolution of the shifting and reverse problems.

Thanks,
Bob Hudson

Bob,

I'm not sure what transmission you have in your '81 SL - is it a version of the 722 transmission? (My 1991 420SEL W126 has a 722.3, which I think was used for all W126 cars, and so your's might also be a 722.3.)

The typical reverse problem in this transmission (lots of posts on it) is for the delay time for shifting into reverse to get longer and longer (up to multiple seconds). Then, at some point, the car starts slipping in reverse, especially when the tranny is warm/hot.

The problem is due to worn B3 reverse clutch plates. Unfortunately, repair/replacement of the B3 reverse clutch in 722.3 transmissions requires removal of the transmission, which means that you may want to weigh the pros and cons of doing a full rebuild, versus just repairing the B3 clutch. In my own case, I just did the B3 clutch repair, as the rest of the transmission looked to be in good shape to the mechanic.

It is worth pointing out that older versions of the 722 transmission (722.0 to 722.2) used a B3 reverse band (rather than a clutch) that has an external adjustment to tighten the band. This can (in principle) allow for a quick, cheap band adjustment to correct delayed reverse engagement and/or some reverse slipping, on the older models. (There are posts regarding this adjustment, as well.)

Bob Schleicher
1991 420SEL, 172,000 miles (my B3 clutch repair was about 3k miles ago)