W126 replacement transmission?

Hi,
After 460000km my 1981 380SE have developed som transmission problems. First, it slips between 2. and 3. gear when accelerating slowly or moderately (but not hard). Second, in reverse, it moves but feels like
the brakes are on (not a problem when the car is cold). I have tried changing oil and filter but to no avail. Any clues?
Rather than investigating in an expensive repair I think maybe I will swap the transmission with another W126. There seems to be different transmission versions (mine is a 722.301): are they interchangable? Specifically, should I be able to use one from a 1988 500SEC in my car?
pej
--
Per Erik Jorde

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Seems like you are located in Europe. I would highly recommends getting 1984 or 1985 380SE transmission. They start off first gear and that is a major difference. They also has the latest valve body for 380SE model year.
The newer W126 transmission has a different ratio and starts off second gear... which would make the car sluggish.
However, all W126 transmission can be rebuilt to start off on first gear. The modification is in the valve body itself.
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Yes.
OK. I think I can get hold of a 1984 model. Only problem is that it has been standing parked for the last 2 or 3 years, and that make me a bit sceptical.

My car already starts off in 2. gear. This is an early (pre-September 1981) European version with high compression (11:1, IIRC), high octane, and reasonable high performance (218hp).
pej
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Per Erik Jorde

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Newer transmission also has some electronics to it... so it is best to check with a MB transmission specialist on which one is better for your car.
Wow... that's alot of horsepower... my USA version had only 155HP.
I am assuming you are getting an used transmission... it is a gamble... look at the odometer and see what mileage it has... if it is high as in 300,000 km... then it is reasonable to think that transmission maybe on its last leg if the body is intact... no accident.
If the car been in accident and has higher mileage... like 400,000 km... then it is possible the transmission is already rebuilt.
If you are getting the transmission dirt cheap, then it might be worth the gamble... I think most salvage yard gives you some warranty that it works.
Also smell the transmission fluid, if it is burnt and dark, you know it is bad.
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Tiger, thanks for your advice!

pej
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Per Erik Jorde

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