So I recently finished a complete rebuild on my 5 speed manual. All bearings, seals, 1st to 5th synchro's and a new 5th gear synchro sleeve (it was toast). Reason - the input shaft bearing had a slight noise and the main reason, it was popping out of 5th gear!! The install was flawless, also installed new clutch and flywheel. Test drove the car and WOW shifted perfect. The clutch was smooth and zero noise!! Very happy until it popped out of 5th gear!!!! All good until you climb a hill (highway speeds) accelerating.

Now I'm CHOKED!! didn't solve the problem!! Installed new motor mounts, not the problem, new shift bushings, not the problem, checked the shifter ball, not the problem, new fluid topped up, shifter cables, all good!! The only thing I have come up with (I think??) is the 5th gear shift fork where the Detent bolts, ball and springs come in contact with the shift fork (3 grooves the ball sits on) if its is scared and damaged I would assume thats the reason it pops out of gear!! I am not ready to tear out this tranny and start over but,.... live and learn.

Anyone come across this problem? I thought i did a bang up job, .... guess not?! Grrrrrr