I have a '82 928 with manual transmission. To switch 4th or 5th gear, a shift lever needs to move right but it does not go there. A shift rod which is connected to transmission and a guide rod which is connected to a fixed point at front should rotate right to move the lever right. I disconnected the shift lever to see which rod does not rotate. Unfortunately, it was a shift rod which does not rotate. I wonder if this is a linkage issue or internal transmission issue. Could anyone give me an advice ? It seems like this is uncommon issue. I couldn't find any case like this.

 

There are two common fail points in the manual linkage.

There is a shift ball cup on the fron end of the shift linkage rod that uses a plastic insert to keep it secure a shift coupler at the rear by the transmission that has bushings and part of the adjustment process to ensure you can get into all gears.

Need to check the forward ball insert and rear coupler bushings first and then the Work Shop Manual has the rigging process.

 

This seems useful for my case.

https://rennlist.com/forums/928-foru...gs-w-pics.html

 

Unfortunately it wasn't a linkage issue. Under the car, I tried to rotate the shift rod to right but it does not move at all. It rotates to left easily though. I wonder if this could be caused my low level of transmission fluid. Differential and transmission are very wet. I assume that they constantly leak transmission oil. If I fill the fluid, is this going to be fixed magically?

 

unlikely,

If you cannot move the input selector to the transmission, then it is likely that the selector rod for the 4/5 plane is slightly out of the detent. Should be simple to fix, but will require the removal of the transmission to fix.