My setup is a 327 SBC with a M20 transmission and hurst shifter on it. It's been mated together for roughly 10 years, maybe 4000 miles on it. It's in my 68 Camaro (my first car that I've had since 1981). I know this is the wrong sight for that vehicle but figured I would get the best advice from the old schoolers. Last year out of the blue with nothing changed I pulled up to a redlight and the transmission would not go into 1st or 3rd gear. I tried adjusting the shifter linkage and got it to where it would go into the gears but would jump out of gear when I let the clutch out. I pulled the transmission and completely rebuilt it excluding the gears. Put the transmission back in last evening. I used the hurst shifter pin to lign up the shifter position, the tabs are in the correct position on the transmission. The transmission shifted great while still up on the jack stands. I let the car down. shifted through the gears well with the clutch pushed in. Backed out of the shop, put it in 1st gear, soon as I the clutch started disengaging it jumped out of 1st gear. HELP ME PLEASE!!!
Take a look in this recent thread, there might be some answers for you. https://www.jalopyjournal.com/forum...-m20-or-damaged-the-clutch-seriously.1106286/
" popping " out of gear usually means you 're not getting full engagement , did you back off & re-adjust the lever stops on the shifter , does it pop out of 2nd & 4 th ? What kind of shape were the sliders in ?
As said above, check the shifter stops. Possibly the jamb nut has come loose allowing the bolt to turn.
I would still go with looking at the shifter and make sure the clutch has good free play. You can probably find online how to adjust the stops. What did the internals look like? Mine was a mess inside. It had blasted out of 3rd when I had my foot in it. Blew the input shaft gear and 1st on the cluster. The rest was wear and tear. My 3rd gear was worn, so were most of the synchros. The sliders were replaced with good used ones the rebuilder had in his stash.
How old is the shifter? You need to drop the levers off the trans. Put the 1/4" pin in place. Everything in neutral, see how the levers line up. Adjust the lugs for the best fit. If the lugs are loose on the rods, you can grind a flat on one side of the lug and put a jam nut against it. How are the shifter bushings? I had mine apart last week and found 2 broken ones. I replaced all 6 and used new clips. The Hurst Pit Pack is like $18 and worth it. I always chuck the nylon bushings if I run across them. Then adjust the stops on the shifter, in 3rd and 4th gear. You'll have to find it somewhere, maybe check Summit for Hurst shifter install instructions.
I'd be looking for shifter fork wear and I've seen them bent. The gear and sliders need to be looked at closely. With my 3rd gear issue, my gear and slider were both bad. Also the sloppy countershaft pin allows excessive space between the cluster and main shafts.
The Jalopy Journal
