I finished rebuilding my 1983 240D Manual Transmission--I had tore it down because I couldnt find a new used unit, and my existing unit could not downshift from 4th to 3rd Gear and often missed 3rd gear. I think I damaged it because for 2 years I used 90W gear oil in it vice ATF
When I opened it I found everything in very clean shape except that the third gear synchro Spring had come looose and had been digested by the transmission.
I rebuilt it carefully with a Beginners Luck. I replaced all the Bearings, Synchros and Synchro springs and most of the snap Rings..
I replaced it in the car last Sunday and with a Huge Gasp, put the car in gear and was pleasnatly surprised to see it worked perfectly and could downshift from Fourt to Third Gear!

The only thing WRONG is that sometimes, in third gear, the transmission will pop out of gear into neutral. Also with the Clutch engaged and at a Full Stop in while in 3rd Gear, I will hear a rattling/whirring noise.

In all honesty I think I rebuilt the transmission very well. By saying that, I mean you can only put it back together correctly, and well (it works), or incorrrectly ( it doesnt work). I got Lucky. So I dont think the problem is the Transmission.

The Linkages have been adjsuted carefully, so the only other place I can look is the pressure plate or throw-out bearing. Can anyone diagnose these Third gear problems?


83 240D Manual Trans rebuild--I finished it, but something is wierd about 3 rd Gear..

Attached Thumbnails