Differences between 81-85 300SD transmissions?
 

I have heard that the 84-85 300SD transmissions are better than the 81-83 300SD transmissions. What was the main difference and why are they better?
:confused:

Due to differences in controls, the 1985 has a different valve body.

The 1984 trans was the best of the lot that would directly bolt into the 1981-83 cars and shift the same w/o playing around with the vacuum settings.

All of the MB factory rebuilds on the 1981-83 transmissions got all of the up-graded parts that the later ones came with.

Thanks Doc... is it still safe to say though that the 81-83s still had good transmissions?

81-83 were basically very good transmissions also pretty much just as durable. most issues before the 1985 upgrade had to do with shift quality esp. cold. (shifting aliitle hard ,for a Mercedes owner). In 1985 a high stall torque convertor was also added and allowed the Diesel rear end ratio to gear alittle more towards fuel economy. 85 than began a more complex vacuum system to soften the shift further . This tranny will fit and work very well (with or without the matching high stall convertor) in a 1981-1984 along with some vacuum modulator adjustmenta as mentioned by the doc.

My harsh shifting (have it set that way on purpose) '82 trans is still hard at work with 274k+ on it....:D

torque convertoe stall values
 

forum, i am in the process of selecting components,body,engine(diesel)tranny,
all for assembling a unit for a drag car,got ohio valley strip local so mostly for 1/8 mile track.
i have not been able to find any specs on the stall rpm of mercedes torque convertors,can anyone help?
also any suggestions to the project will be appreciated.
larry perkins lou ky

one bump
 

one bump

My stock 81 stalls at 1800rpm, but thats all I know

Also the 603 engine develops more power than the 617

tranny brake
 

1800 thanks, that will give me some data to work with,have to believe that a tranny brake will be needed to operate best. would have to plan for 4000 if the horse power gets to where i think it will be for the 603.
larry perkins