I have an ’82 and a ’85 300D, both turbo.
The 85 has a speedo that goes up to 120, the 82 goes up to 80mph. The gearing on the 85 definitely feels like it is different ratio on the hwy. The 82 tranny seems problematic and the 85 tranny works perfect even though it has more miles. I am very familiar with the potential problems associated with the 300D tranny’s and the vacuum system, 3/2 valves, modulator etc. and short of doing a complete and accurate diagnostic rundown on the 82 i am out of options. I have not garage to work in, no concrete floor to work on and am missing at least a couple hundred dollars worth of the tools, kits etc. If there was someone anywhere near me (Seattle) i would pay them to do it but it has become very clear to me that there are VERY few people who can and/or will take this on and do it correctly if they did it could easily cost 500-1000. I have already had 2 people who said they could do it but both of them basically just worked on the bowden cable and the modulator without going thru the rest of the components involved with the shifting/tranny set-up and called it good. But after 10 yrs of having a proper shifting car i'm buying it. I was hoping to get Kent at Mercedes Source to do it but he's not taking any new customers.

Couple of questions,

First (simple one) are the tack amps from the 82 & 85 interchangeable?

Is it possible to do a straight swap the tranny from the 85 into the 82 or is there more to it than that?