Symptom: grinding when trying to get into reverse, and 1st, but not as much.
My body man was saying how much effort and travel was required to move the car around, so after getting the car back I've been all through the clutch adjustment procedure today.
First off I discovered that the helper spring was not set up correctly, it was not loaded because the pin protruding from the spring mount shaft was
behind the stop tab. (I'm not sure how the arm was able to move forward to disengage the clutch without being blocked by the tab that stops it from going back come to think of it, but it did)
After getting the helper spring in right and setting the 1.2mm gap, my cable was far too extended to be near the correct position, and I had to rotate it to screw it all the way in at the pedal cluster. Eventually I was able to get the slack out of the cable between the arm and the cable mounting nuts and close the gap to 1mm, but there is excess cable "bunched" toward the firewall (maybe 1" or even 2" longer than necessary), leading me to question if the cable is as effective as it could be.
I still don't have a pedal board with a stop, so I had a helper depress the clutch as much as would "seem" normal to shift, and only got 16mm travel. Then I had them press it "all the way", and the travel was 25mm per the instructions. I guess that is OK, although I will know better when my pedal board with stop is installed. It seems like that was an excessive amount to have to push the clutch to get the needed 25mm. Hopefully that would not be necessary to shift while driving! The seat was way forward and the toe extended to get the 25mm.
So, the setup is technically correct as far as what I have been able to read. The pedal is firm and starts to pull right away (no pedal slop).
Now, getting into first is possible but requires absolutely everything.
Getting into reverse is impossible without grinding. If fact, I start to hear a nicking sound if I depress the clutch as far as I possibly can, and still it grinds (the gear is seriously spinning)
I am looking for some help from you guys who've been doing this a while. Is it:
1) cable to long (car is a '76, don't know what year 915 is, but not original, maybe the cable I ordered for '76 is off a little).
2) damaged pressure plate diaphragm from previous incorrect setup (pedal being mashed to floor since pedal stop absent). Seems unlikely since I think damaging the diaphragm would be evident with engagement problems not release problems.
3) I have a throw arm mis-matched to my transmission? I'm not familiar with the number of changes that may have taken place, but I think there was a change in '77 to use the helper spring. My car matches the pics in the 101 projects article.
4) I have transmission in need of work
or none of the above?
I'd sure appreciate any tips to help figure this out.