I have a 722.389 transmission in my 1994 W124 wagon. It's showing early signs of needing repair (slow to engage reverse, etc). I purchased, before realizing the various differences, a transmission from a 1996 w210 which is 722.329. The transmissions appear to be exactly the same with the exception of the tail housing which has a different configuration for the transmission mount, and the change from a mechanical driven speedometer to an electronic one.

I searched and found where someone was trying to swap parts between a 722.3 and a 722.4 transmission which wasn't going to be possible due to differences in those transmissions, but does anyone have actual knowledge of the internals of the 722.3 series to know if I can make the 722.329 work in my w124 wagon?

FYI, the newer transmission only has 13K miles, so I'd really like to use it to replace my tired 260K mile transmission.

Sorry I guess I missed asking my question which is can the tail housing and the mechanical speedo drive be swapped over from the 722.389 over to the 722.329 to accomplish what I'm after?

I'm going to move forward with this project, and will post the results for future reference.

youre gonna need the housing, rear seal, theres a gear inside in which it drives the speedo cable. sounds like a real project, I would honestly just have your transmission rebuilt.

It took forever to get to this project, but it's a very simple swap. The speedo gear is mounted to the rear most disc in the transmission. This disc is notched and is part of the park mechanism. I swapped over that disc, and the tube that feeds lubricant to the speedo drive gear, and bolted the new housing in place. The case is exactly the same, so everything bolted up easily.

The engine and tranny are going back in the this weekend. i'll post an update again when the car is back on the road.

BTW, I read the transmission number incorrectly. The w124 transmission is a 722.369 not a 722.389 as I originally stated.

Hello everybody!
Finally, did it work?

Yes it did, but something a few months ago failed. I believe it's the governor as the transmission won't shift now. Too bad as the car it wound up in probably will be parted out.