lost 5th on my '77 5spd.
01-13-2015, 07:18 AM
#1
Instructor
Thread Starter
lost 5th on my '77 5spd.
A while back I've lost 5th gear on my '77 5spd.928. It happened when making a bad downshift from 5th while taking an exit on the highway. I could hear a sort of "bang" comming from underneath the car.After that I couldn't shift up to 5th, all other gears are fine.
Can it be the rear coupler has shifted position? I've tried to adjust it but only on the shift rod side (I'd hoped to solve the problem without moving the dust boot over the coupler again.) This didn't solve the problem. Can it be, despite adjusting the shift rod, that it can't travel far enough to get 5th?
Ideas are welcome :-)
Can it be the rear coupler has shifted position? I've tried to adjust it but only on the shift rod side (I'd hoped to solve the problem without moving the dust boot over the coupler again.) This didn't solve the problem. Can it be, despite adjusting the shift rod, that it can't travel far enough to get 5th?
Ideas are welcome :-)
01-13-2015, 08:56 AM
#2
Rennlist Member
Here is my experience and feedback received on a similar/same issue.
https://rennlist.com/forums/928-foru...ear-79-ob.html
The end result was a swapping trans boxes.
https://rennlist.com/forums/928-foru...ear-79-ob.html
The end result was a swapping trans boxes.
01-13-2015, 11:02 AM
#4
Rennlist Member
This statement may hold the key:
"The syncro does not do the work to "hold" the slider onto the actual gear. The teeth on the engaging teeth and the slider both have a "negative angle", which keep the two "locked" together".
Either the shifter is not "pushing" the slider far enough to fully engage, or there is severe grief on the actual 5th gear teeth. The grinding noise is the syncro, but keep in mind that the part of the slider that "touches" the syncro wears also."
Gregbbrd
A couple of years later when I actually tried to return this car to driver status I noticed that the front ball cup was a 928MS aftermarket pc. It was very loose and gave a lot of fore aft play. That may or may not have been related to my issue but it was never addressed. At that point I already had another trans and was ready to make the swap,along with the front ball cup.
If, while in gear, you have any play either forward or backward, I would replace the liner to the cup of the front ball cup. Or just replace the entire front ball cup. I was able to do this myself with the assistance of a ratchet strap. The pictures from Dave give a great idea of all of the parts involved in the shifting process.
"The syncro does not do the work to "hold" the slider onto the actual gear. The teeth on the engaging teeth and the slider both have a "negative angle", which keep the two "locked" together".
Either the shifter is not "pushing" the slider far enough to fully engage, or there is severe grief on the actual 5th gear teeth. The grinding noise is the syncro, but keep in mind that the part of the slider that "touches" the syncro wears also."
Gregbbrd
A couple of years later when I actually tried to return this car to driver status I noticed that the front ball cup was a 928MS aftermarket pc. It was very loose and gave a lot of fore aft play. That may or may not have been related to my issue but it was never addressed. At that point I already had another trans and was ready to make the swap,along with the front ball cup.
If, while in gear, you have any play either forward or backward, I would replace the liner to the cup of the front ball cup. Or just replace the entire front ball cup. I was able to do this myself with the assistance of a ratchet strap. The pictures from Dave give a great idea of all of the parts involved in the shifting process.