Post deleted by tinytrooper

Throwout bearing has nothing to do with engagement or disengagement of the clutch (meaning a good one or bad one will not matter). As long as you have one in reasonalable condition, you will disengage and engage the clutch the same way. If a throwout bearing is bad it will make whirring sounds, vibration or rattling when the clutch pedal is pressed. Definetly won't be smooth and quiet, but the clutch will engage and disengage. All it does is act as the end of your hydraulic ram to press into the pressure plate.

If you are having problems engaging/disengaging/ plus clutch slippage I would think about things like

-hydraulic system bleed out air bubbles
-dirt/mud/water on input shaft, in bellhsousing, in between p.p. and flywheel and clutch disc
-surfaces no longer greased due to water and dirt, splines not smooth
-burned/glazed/contaminated disc or flywheel

also rare things like:
pilot bushing worn out (causes wobbly input shaft)
bent or damaged input shaft or input shaft splines
damaged pressure plate fingers

this is just a partial list of course.

Also bad rear main seal can add oil to the mix making this even more fun.

How is your distributor o-ring? (big source of oil leaks that can affect clutch performance.)

If your clutch is quiet when you press the pedal my guess is your Throwout bearing is OK

Thanks for the reply but the question was more geared towards the throwout bearing clogging or seizing (sp) on the shaft due to dirt or some sand causing it to hold the clutch...I'm aware however of how the system works, this has been an on going problem and I'm wondering if anyone has ever ran into this or something like it...after washing out inside the bellhousing with high pressure water the clutch resumes normal function....

The throw out bearing, if I remember correctly (*looking back through my mind's eye...*) is a very much sealed unit and is NOT prone to clogging or seizing due to sand or mud.

Were I you, I'd look at some of the more obvious culprits that Chris mentioned.

Best o' luck,

Cracked tine on the clutch fork? Damaged finger on pressure plate? Separated friction pad on clutch disc? Spring fell out of disc hub? Binding in hydraulic cylinders? Binding of release bearing due to irregular surface of input shaft collar (cracked tine would cause this [uneven pressure])? Siezing pilot bearing?
Just a few things that come to mind. G'luck man

Look at where I'm coming from: if you replaced your throwout bearing with a solid ring of steel, your clutch would still operate normally. Meaning it would engage / disengage fine. There would be nothing to cause it to bind or hold the clutch or slip the clutch. It would just make a ton of noise, heat, vibration, and eventual failure, but it would engage and disengage the clutch the same way. This is why i think your problem lies elsewhere, if I understand your problem correctly.

That bellhousing can get filled up with muck pretty easily. Have you thought of drilling a hole and mounting a garden hose fitting to it? I've seen that done on frames before. You hook up your hose when your done mudding and blow out the mud. Not sure if that would compromise the bell though. Budbuilt toyota frames come with those fittings for easy cleaning.

Ok I went back and reread your problem do you mean the shiftblock (I don't know what it is called the thing the TO bearing is attached to) is sticking to the input shaft collar due to mud and crap and not sliding correctly until it is washed out?

Yes. Surely "mud and crap" could cause binding and also destroy the integrity of the collar on which the TO bearing and sleeve slide upon. Although I haven't installed a clutch in a while, Sachs was one of my favs so the "no engage, sometimes slips" most likely are external ailments to the clutch assy.
The tough engage issue could be due to the pilot bearing snagging the input shaft giving it enough motion to prevent successful synchro/hub engagement.
The slipping could well be in the release bearing travel resistance.
These are merely suggestions, proper diagnosis is tough without personal examination. Just tryin t'help.

Ooooh, ooooh I have an idea. <img src="/forums/images/graemlins/smile.gif" alt="" />

Either bypass, or replace the clutch dampner thingy. It is a small, square thing bolted to the firewall (or front DS fender) that is between the MC and the slave. It should have a bleeder screw on it too.

Why you ask? Well, if the problem was engage or disengage only, I would suspect the TO, maybe. You also said the problem continued after a new clutch. So, the suspisusion is not with the components within the bellhousing. It was not desctibed the exact state of the various components that were removed, but it seems to be implied that the first TO bearing was contaminated. It may have been concidence. A) to fill the bellhousing that much, would have destroyed the rest of the components too. B) To truly have seized, it would not have been driveable.

As Chris alluded to, it would have destroyed the pressure plate fingers in no time and made a very very bad noise. Besides, contaminated bearings (especially ones with grit) do not usually seize, they eat themselves from the inside out and become very loose. Now, I am not saying that yours was not siezed, but I would call it less common than the above.

Now, assuming that clutch #2 has not been pulled, I would bet that TO bearing #2 is OK. That leaves a problem between the clutch fork and the pedal. We can assume the the MC and the slave are OK, but they may not be. What that leaves us is the dampner. It is supposed to modulate the engagement for smoother operation. When it fails, it can prevent engagement, disengagement or whatever. But, it usually does it randomly. Hosing out the bellhousing may have seemed like it fixed the problem, but I would bet it was enough time for it to sit and "unstick" itself.

There, that is my 2 cents.

Michael

Ahh there you go now we are getting somewhere... The sachs kit wasn't put in due to a problem, it was put in due to needing a new clutch since I replaced the tired 2.8 with the 3.4... The clutch works great day to day driving ZERO PROBLEMS... The only time there is a problem is during or after wheeling then the seizing occurs... This is a post for ideas or suggestions for preventing this or something... I have owned numerous troopers and this truck gets more wheeling action than all of them put together, I'm just wondering if anyone else has had this type of problem before... I have wheeled with several other makes of 4x4 and mine seems to be the only one suffering, although it doesn't happen all the time...Just reaching out to see what the concensus(sp) says...thanks for the replys