722.310 Transmission help needed 83' 380 SEC - PeachParts Mercedes-Benz Forum

gedeonbgjr · #1 07-10-2007, 10:57 PM

Hi,
I need help diagnosing a problem with my 1983 380 SEC transmission. I rebuilt the trans replacing all clutches and steel plates, upgraded the B2 piston. The trans has a very harsh shift into reverse and occassionally will clunk when downshifting to first gear. All upshifts are very smooth and the trans seems to operate great except for the 2 described problems. I cleaned the valve body during the rebuild and reinstalled all the parts the same way they came apart. Any help or suggestions would be greatly appreciated.
Thanks in advance.
Bob

david s poole · #2 07-11-2007, 10:11 AM

did you replace modulator? or is it poss that the mod was tightened to cover the flair that was created by worn clutches[before you rebuilt]?

gedeonbgjr · #3 07-11-2007, 10:48 AM

David,
Thanks for the reply. I did not change the modulator although I do have a new one. I wasn't sure how to check the pressure after installing a new modulator. The manual I have describes connecting a gauge (routed to the inside of the car) and driving 30 miles per hour to check the pressure. I did make some change to the old mod by turning in the adjuster 1 turn but it didn't make any difference. I was thinking that the valve body would need a rebuild, not just a cleaning. It is a first gear start valve body. Am I on the right track thinking the problem is related to the valve body?
I wasn't able to drive the car before the trans rebuild because it needed an engine rebuild and had sat in a garage for 11 years. The car had 79,000 miles on it. I am sure the trans was worked on because there was red RTV everywhere.
Thanks, Bob

david s poole · #4 07-11-2007, 04:17 PM

your mod press is too high turn back the turn you moved it plus another 1&1/2 [ccw] and see what happens.

gedeonbgjr · #5 07-11-2007, 11:07 PM

Thanks for the info, I will make the changes tomorrow and let you know.
I appreciate the help.

gedeonbgjr · #6 07-12-2007, 09:37 AM

David,
Thank you very much for the help. I backed off the adjustment on the modulator and the harsh reverse disappeared. The upshifts still work great too.
Thanks again, Bob

david s poole · #7 07-12-2007, 10:29 AM

glad to be able to help.