Another clutch problem

92 XJ, 5 Speed.
Entire clutch setup was changed some time ago (1.5-2 yrs), including resurfacing the flywheel. (I read maybe you're not supposed to do that)


No fluid leaks, it shifts like a dream until it warms up. Then I can't get it into gear from a standstill, like the clutch isn't fully disengaging. But the weird thing is once I finally manage to jam it into gear, the clutch doesn't grab right above the floor, like it does with low fluid levels/air in the hydraulics. It's like the last inch or so of the clutch travel isn't really doing anything. Also, when its hot and doesn't want to get into gear, if I push the clutch pedal in and rev the engine it will slide right into gear. Maybe the clutch disc is warped and dragging a bit even when the clutch is disengaged? (but it doesn't chatter). Or maybe the pilot bearing is worn or sticking, turning the input shaft even when the clutch is disengaged? Or maybe the master cylinder is a bit weak? Any ideas?

Sounds like it could be the synchros in the transmission, not a clutch problem. Did you change the tranny fluid w/ the clutch. There's some speculation that tranny fluid NEEDS to be only GL-3 grade, recommended by Chrysler.
The synchronizers contain bronze, and sulpher in the gear oil (other than GL-3 containing no sulpher) will eat away at them. If it's affecting first gear only, synchros take a beating if you try to force the tranny into first as your coming to a stop. Stop rolling before going into first.
When your tranny's cold, the thicker fluid will help with shifting. When things are warmed up, revving the engine does two things: one, you stir up more fluid by spinning the mainshaft faster, and two, you may be "match shifting" accidentally, which is matching engine revs to transmission speed, to smooth shifts.
If you're insanely good at that technique, you only need your clutch to start off...let the revs drop when upshifting, and blip the throttle when downshifting. Having a tach is almost mandatory, but most big rig drivers do it by ear, and feel.

Hope that helps,

Steve

I doubt it's the synchros, supposedly if the clutch is disengaging properly when the vehicle is stopped and idling, you can get it into reverse without grinding as long as you wait a few seconds after pushing the clutch pedal. When it gets hot I have no such luck. Did I mention when it gets good and hot you can't get it out of gear that easily either? I've heard about trannies shifting worse when hot because of worn syncros, but I can't get it into second, third or reverse from a standstill any easier when it gets warm. It goes into gear more easily when STOPPED if I rev the engine. That's not worn syncros. If the syncro's were bad revving the engine in neutral at a red light would make it harder to get into 1st, not easier. Maybe I didn't elaborate enough in the first post. It's from a stoplight I have all the trouble, downshifting into 1st while moving isn't any harder than it ever was.

I suspect that resurfacing the flywheel (which is specifically addressed in the FSM -- it says not to do it) may be the problem. There is no adjustment in the hydraulic clutch. When you resurface the flywheel, the entire pressure plate and fingers sit a few tousandths farther away from the tranny than the OEM setup. With a 92, you still have the internal slave cylinder. I think it isn't depressing the clutch fingers fully. If you know how much was machined off the flywheel, you could drop the bellhousing and shim the slave cylinder away from the bellhousing by that thickness and see if it makes a difference.

Or just replace the flywheel.

That is a possibility, but I did get about 50,000km(30,000)miles before it gave trouble. As the clutch wears, the clutch should disengage sooner/easier, right? Unless it is the pressure plate finger fatiguing faster than the clutch is wearing. It worked well up until this spring, it was machined about almost 2 years ago now I believe.