Clutch issues, I'm stumped.

[MOBS]

Ok, I just recently replaced the friction disc, pressure plate, throwout bearing and flywheel. The issue I'm having is that after the engine has warmed up and been driven about 15min or so, the clutch acts like it's dragging, just enough to cause the gears to grind when trying to put into 1st or 2nd at a red light. If I rock the shifter from neutral to first a few times it will sometimes go into gear hard(meaning while clutch is still pressed, the truck wants to slightly roll forward a bit), otherwise I have to shut off engine and put in gear, crank up then go, which has caused a few horns to honk and my classic "i see the horn blows, what about the driver?" response. Ok, I also noticed today that when sitting on a perfectly level surface, if I bump 1st a few times trying to get it in, the vehicle lurches forwards a tad, so the clutch is definitely dragging. The pedal also is no longer easy to engage into gear, for instance, when you press it 90% of the way down, it's a smooth transition, then the last 10% feels like it slaps the bump stop, then when easing off the pedal, it jumps from the 100% mark(all the way down) to the 90% mark and that's where it's grabbing....so I would think it wouldn't be grabbing at the 100% mark, but it seems to when it's been driving alot. I first noticed this after idling in 1st from the bottom to the top of a parking garage, I couldn't get it into any gear when it came time to turn around. Luckily I had people up there to push my truck backwards enuff that reverse fell into gear(rpm matched shifting), then i could aim downhill and drop outta reverse and roll into 1st....all that time the pedal was all the way down. Now here's the funny part, the system has been bled twice since install, 3 times including the bleed after install, no air ever came out on the 2 follow-up bleeds. There's no fluid loss, so it's not the lines, fittings, or slave cylinder. I thought maybe the master was leaking back into reservoir, so I had it checked at the dealership and they said it's holding pressure, but they also mentioned that the underhood heat could be causing the brake fluid in the lines to lose it's viscosity and therefore not hold the pressure. Makes sense since it seems to only do it after the engine has warmed up. As far as I know, I have the correct fluid, used the GM brand syncromesh fluid that's recommended for the world class trannies.

Just throwing this up to see if any of it sounds plausible or if anyone has had a similar issue. This only started about 200miles or so after clutch change, the original clutch assembly was a progressive type pressure plate, but I switched to the standard clutch assembly. The original flywheel was worn completely out, so the new flywheel lowered the tolerances by a good bit I'm sure, so this problem could have existed pre-change, and not shown itself till afterwards. Currently this is my daily driver until my green 95 is finished(torn down into a gazillion pieces right now), so it would be nice to have it driving right, it worries me at times because when it gets so bad that i have to cutoff engine to put into 1st, and i take off, sometimes it wont go into 2nd until i let the rpm's drop enuff to sorta half-ass rpm match and then it drops into 2nd(all the while clutch being 100% at floor)....it's done that twice, so i haven't driven it except short distances here lately.

Any help or opinions would be appreciated....but no, I won't switch to an automatic, so don't even start that lol.

-MOBS.

 

[sewlow]

Did you change the cone on the end of the tranny, that the T/O bearing slides on? Clutch fork bent?

 

[FastOrange]

just take the cylinder line, break it in half, crimp it off, and your good to go.

 

[MOBS]

I changed what was in the kit, it was a so-called deluxe kit, but no, all it had was the t/o bearing/assembly, pressure plate and friction disc....replaced flywheel also though. If clutch fork were bent, wouldn't it cause it to give those symptoms when it first cranked, not only after warming up? Unless it's combined with engine heat or another issue. I'll add the 'cone' to the list of stuff to check/replace. Thanks for the heads-up on that.

 

[sewlow]

I just threw the bent fork idea out there as something to check. I always change the T/O cone when doing a clutch, even if it looks O.K. Cheap insurance, & a PITA to take everything apart, again, just for that.

 

[fun4me]

Sounds like fluid is bypassing the piston in the slave cylinder.

 

[sewlow]

Sounds like fluid is bypassing the piston in the slave cylinder.

No-one put tranny fluid in there, did they?

 

[barebones 1500]

Sounds like Slave cylynder to me as well. Could also be master cylinder, for me it was both. Master seized up on me somehow and the slave blew up a week later. But i did learn that the truck shifts fine without the clutch.

 

[MOBS]

Did you change the cone on the end of the tranny, that the T/O bearing slides on?

Ok, now that I think about it, I think it came all as one piece, if not, then I didn't do it....I did this last summer, so kinda fuzzy in the memory dept.

 

[MOBS]

just take the cylinder line, break it in half, crimp it off, and your good to go.

If I knew I could get a push in either forwards or reverse everytime I had to stop, in short that would be doing just about what I am doing now. RPM-matching is hard on synchros, unless they're made for it. and you....