Hello Guys,
I have a 1992 300E that i have recently had the transmission rebuilt on.
The problems that I am having are as follows.
when the car is cold it shifts hard from 1st to 2nd. in easy neighborhood driving, or would that be from 2nd to 3rd as I have been told that the cars start in second gear. I can do my 42 mile commute to work with relative ease yet when I turn on the A/C the car wants to stutter through its gears and I would definitely think it is starting in 2nd because I really have to mash hard on the accelerator to get it moving which I suppose it then has to downshift and the car picks up fine. But then it starts to stutter through gears again. At this point turning off the A/C really doesn't do much good. after about 1/4 mile or so with no ac running the car will start to shift better again though still not perfect. could this be a tuning issue as it exasperates the tranny issue by placing more load on the engine?
or is this something I should take it back to the transmission shop to fix?
I also have a 87 300e that shifts fine and no difference in power when the a/c is on. Where should I start with this and what should I check for while troubleshooting? Any help would be greatly appreciated!

No, your '92 has first gear start. Hard shifts when cold could simply be the warm up feature that holds the car in 1st for an longer time and then finally shifts to second at a higher than usual rpm. This is designed to warm up the catalytic converter faster.

Sounds like maybe the vacuum line(s) weren't hooked up correctly or the cable to the transmission (Bowden cable) is incorrectly adjusted. If the vacuum line to the transmission modulator is disconnected you will get hard shifts.

Steve
'92 300E