1980 300td transmission conversion to later model with Bowden cable
 

Has anyone "updated" their older w123 with a newer transmission?

I am loathe to continue troubleshooting my current transmission aggravations with my 1980 TD (vacuum-only control trans). I have access to a reasonably-priced replacement from an '82, which will come with linkages and a usable Bowden cable.

Has anyone done this "conversion"? Or is there an existing thread you can point me toward?

Right off the bat I would imagine I am dealing with:

- changing the speedo
- needing a different vacuum control valve
- revising the vacuum setup
- different front driveshaft?

Thanks in advance, etc.

i know you can go backwards, because my 81 300D has the trans from an 80 300SD. so they took out the bowden cable and put in the rod. i'm assuming the reverse could be done?

i think the VCV is the same for all model years that used it. the vacuum setup on the later models should be simpler anyway, since you can bypass the 3/2 valves on top of the valve cover

Maybe I ought to have just asked:
 

What differences will there be, that I must be aware of, to swap in an '82 transmission into my 1980?

Thanks

Zack I swapped 1982 to a 1980D what you need is rear trans mount from 82, spedo cable with square end, neutral saftey switch is different ( splice the wiring)throttle linkage with bowden cable mount and rerout vac to make trans work well.Exhaust mounting is also something you need to mess with driveshaft was fine.

Ironhead nailed it!
It's an easy switch and a much easier trans to adjust.