OM617.952 transplant into a '78 300cd - tranny issues, other considerations?
 

I have a 1978 300cd with a very tired motor and a suspect tranny. There is a chance I can trade one of my parts cars for an intact driveline from an '82-'83 w126 300sd (car was junked due to rust years ago and the vendor can't remember exactly what year it was).

From my understanding, not all the transmissions used in the w126 will fit into a w123. Am I correct?

If so, does anyone have any guidance on year(s) or model number(s) that will fit?

Also I would assume that I will also need to install from a later, turbodiesel w123:

- "horns" for the motor mounts
- oil cooler lines
- air cleaner assembly

- and what else?

If you can point me to a fellow lister, or an existing thread, much appreciated.

Cheers

mac

Im doing a swap of a 82SD motor to my 82CD. hold on to your motor, there are several differences i am finding on mine which may help guide you

oil filter housing (different pressure sender type)
turbo oil supply line
oil cooler line bracket near driver motor mount
AC lines

since your coupe is non turbo Im not sure what applies, Im also replacing any common parts that are better on the SD motor

I am also replacing the turbo drain, the dip stick orings and the air cleaner drain orings while its out

The 84 tranz is all its own for 84 sd and are different that all others--yours would be common , i got a 722-309 from a 84 euro gasser ce thats also used in the SD so perhaps the other 309's are pretty do able in your swap.

Why don`t you use the 300CD (W123) trans with the 300SD (W126) engine? The W126 engine is going into the 300CD, right?

The W123 uses a mechanical speedometer, and the W126 uses an electric driven spedometer.

Charlie

Couple of reasons: I was told before that a trans out of a non-turbo would not survive there; and the trans itself is kind of suspect (weird noises, never had that before with a Mercedes trans). But it shifts ok.

Tks

bump
 

Anyone got more info?

Not sure about compatibility, the mounts have different part numbers.

The info I have calls an SD engine a 617.951.

The 617.952's were in 123's.