'88 to '90 300E Tranny Swap? Will it Work?
 

So....at 268,000 miles, my tranny went south and I just can't justify spending big $$$ for a new/rebuild. I found a used one from an '88 300E w/125,000 miles. Does anyone know if this is a direct swap project? If it would require mods? If it wouldn't work at all? If no knowledge, do you know where I can find out? I've done the search here and can't seem to find anything directly related.

Your input is appreciated.

Bill

It's a direct swap check the transmission numbers on the bottom right by the oil pan to see if they the same it should be the same transmission

At least reseal the thing and replace the reverse clutches while it is not in a vehicle.

When I bought my 560 years ago, it had just over 150k on the odometer... and a factory reman transmission installed. So, no telling how the 125k on the potential unit you are going to install was driven. All city? Going to have far more wear than an all freeway.

Only thing I would investigate is if the '88 transmission has that solenoid on the left front for pulling out the 2-3 upshift when the motor is really cold (think, emissions). My '89 300E does from memory and my '90 300SEL does for sure.

Agreed. If you can't justify the rebuild, then buy the used and rebuild that one yourself if you know how. Definitely replace rear main seal and I would even do the transmission mount, tranny pan gasket/filter, flex discs, shifter bushing, vacuum modulator, and center support bearing while you are down there. That way you won't kick yourself later if you don't do them and one fails causing you to have to drop the tranny again.:D