The 4-speed manual on my 1983 240d is stuck in reverse.
After determining that external shift linkage was not the problem I pulled the transmission out of the car. The shift arms for 1/2 and 3/4 go in and out of gear but the arm for reverse just flips back and forth with no resistance. Something has definitely come loose inside the transmission. Is this a hard one to fix? I've never taken a transmission apart before. I don't even know where to start.