Are early/late W123 auto transmissions interchangeable?


More specifically, can I install an early (1979) trans into a late model (83) car? 240D.


I think the shift controls are different but dont know exactly how they differ. Bowden cable? Vacuum? Dont really care if it stays period correct, just want it to work.

"INTERCHANGEABLE" Yes...
From a bolt in standpoint, straight forward.
From a controls standpoint, it would be very helpful to have a complete donor car at hand. The controls are indeed different.

1979 240D had no vacuum or cable. There is a rod that goes from the trans to the throttle linkage.

I would not do that swap. Fond the right trans for your car.

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Milan Brown 1979 240D, rebuilt OM617.952 turbo diesel, rebuilt 722.315 transmission (my only daily driver)

Instagram: @maximed93

when the original 617 died due to oil pump failure in my 78 I had a euro 85 non turbo 617 put it from a wrecked car. I made sure to keep my non vacuum operated transmission because its simpler and more reliable.



not sure what would be involved in swapping a different transmission in if there is anything different on the body but the 78 trans fits nicely and drives perfect behind the 85 motor.


my 2 cents

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1978 300D

Similar situation; I have an 82-83 240d that isnt shifting properly. Checked various things and also the mech is leaning towards bad transmission conclusion. I replaced my 79 auto with a manual and have it sitting here doing nothing. Seems like a cheap fix to install the 79 auto into the 8x car if I can get specifics on differences and needed parts make it work.

For sure you would need all the linkages and stuff that go on top of the valve cover , in addition be sure they connect to both the IP and then the connector to the trans. otherwise being that they are mechanical I don't see this as a difficult swap (driveshafts and mounting aside)

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1978 300D