I'm having trouble getting my trans to shift good. I put this engine into this car and am still trying to work out the bugs. It shifts hard from 1st to 2nd and sometimes from 2nd to 3rd. 3rd to 4th is perfect. I went through the vacuum system and replaced all of the hoses. I checked it with a pump and it is holding very well. I adjusted the throttle linkage and the cable by the Mercedes service manual. The modulator is adjustable and I have bettered it some by adjusting it. At 3/4 throttle or above it shifts good, but at a normal take off it's like I have a shift kit in it. In fact if it is a little slick outside it will spin the tires when it shifts 1st to 2nd. I don't know what to do next

Nscarpi,

These cars are known for a hard 1-2 shift. I don't know why but I bet someone on this forum can explain the reason for this. Transmission also wears out on 2-3 shift more often than other places.

Rough idle is also a persistent issue (re your other post). If you have adjusted the pump and have new engine mounts, I don't know what else you can do. My car will idle perfectly sometimes and then get kind of rocky other times. Goes with the territory to some extent I have concluded.

Nic
'85 300CD @ 158k miles

The hard 1-2 shift was somewhat alleviated by replacing the vacuum valve on top of the engine. I had it done (I know...taboo on a DIY website) so I don't know if he adjusted the transmission module, however, it shifts much better now...you feel it shift but it feels good and i don't get whiplash anymore. It also used to downshift abruptly and loudy into first when slowing down, which has also disappeared with the work I had done. It only cost me $200. The valve is $72.00 at my parts store and had I known, I would have done it myself. I thought my tranny was gone so $200 didn't seem that bad at the time.

__________________
1982 300D Turbo "Helga"
380,000 miles

Until the transmission fluid heats up to operating temp, you'll feel the shifts. I intend keeping the shifter lever in "S" (for going up "slopes") tomorrow morning until the car reaches operating temp. Let you know if it helps.