Transmission Question

[Hertie Gertie]

So I was driving my 79 FJ40 this weekend and something weird happened. As I approached a stop sign, I pressed the clutch and downshifted to first, but I was completely locked out (like there was a wall in the way). I kept the clutch engaged and tried getting back into second and was also locked out. Pumped the clutch a couple of times and tried 1st again with no luck. I pulled off to the side of the road, turned it off and after a minute I was able to re-engage 1st and drive home. I also noticed that the shifter slipped out of 3rd gear while I was driving on city streets around 30-35 mph a couple of minutes before this happened. Earlier in the morning, I also noticed that depressing the clutch to the floor and shifting to Reverse caused the transmission to grind.

Checked the master cylinder and it was topped off. Wondering if the shift lever seat and shift lever cap going bad could cause this. May also look at adjusting the clutch slave cylinder. Anyone with more auto experience, which is everyone on here, have any ideas. Fixing this would be a great social distancing project. Plus, the top is off and I don't want it sitting in the garage during the best driving days of the year. I appreciate any and all thoughts?

 

[lt1fire]

So it doesn't grind at all when you try to put it into gear?

Have someone depress the clutch and check the slave cylinder to see if it is working.

Edit: re-reading this i'm guessing it is not currently doing this right now?

 

[MBest75]

Someone can probably hop in and get technical here, but Synchros are possibly your issue with the downshifting. Worn clutch probably on knocking out of gear. Lots of threads all over about Synchros wearing out in a 4spd. I own a 78, original transmisison, for mine, it's just a little tricky, lots of times I can't get into 1st, R and 2nd and just have to be A. moving right speed, B. A lot less Throttle the shift/zero (regardless of clutch depressing) and C. Reverse, best to move forward a little (Bump forward in 1st or roll). For some reason, if it's grinding going straight into reverse, putting into 1 and then back to R gets the job done. Haven't had mine knock out of any gears yet and very limited issues with clutch slippage (despite a steady rear main leak)

99% sure mine has a demon in there, but since I'm planning to do an engine swap, I'm just ducktaping it for now...

 

[GLTHFJ60]

1st issue (not being able to shift into gear) is most likely caused by failing clutch hydraulics.
2nd issue (slipping out of 3rd) can be caused by a worn out shifter bushing

 

[AJR]

Clutch hydraulics are cheap and easy to fix, I would recommend to start there. You might find that the other issue is something you could live with for a while.

 

[Cirbo]

Bad clutch master or slave. Change out both, along with a new flex hose to be proactive.

 

[Rice]

1st issue (not being able to shift into gear) is most likely caused by failing clutch hydraulics.
2nd issue (slipping out of 3rd) can be caused by a worn out shifter bushing

What he said ^^^

To isolate the hydraulic issue ... If the slave cylinder is failing there will be fluid getting past the seal and dripping. On the other hand, a master cylinder can fail and there be no leaking. If you replace the master be certain to bench bleed before installing. Both cylinders are easy to reach and are jobs.