Slipping Clutch Question...Help!

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Mar 18, 2007
Altanta, GA clutch has definitely started slipping, but my question is: could that literally start happening from driving perfectly one second to parking and getting in an hour later and the pedal feel is completely different and the clutch is slipping!? Seems like it would be a tiny bit more gradual of a loss?...

It seems like there may be something that's sticking that a possibility? any ideas? I can do the work, but really am not excited about doing a clutch replacement if that's not the issue. The truck has 119k mi on it and was running and shifting flawlessly...then an hour later...crap.

How long does a clutch in a 40 last....assuming it hasn't been overly abused?

Thanks guys...
I really haven't heard of a clutch going out as abruptly as yours evidently did. If the T.O. bearing is hanging-up on the bearing retainer (tube it slides on), the bearing may be preventing the clutch from reaching full engagement. That prospect is remote, but has happened in the past.
Is there some way to free up the TO bearing? Anything I can do through the inspection cover? Thanks for the help...
Jim, I just read another clutch post of yours regarding TO bearings riding the fingers and causing a ringing sound, then premature failure. When I drive there has always been a ringing/rattling type sound coming from the tranny area...could that have been the TO bearing riding the fingers like you had described for the Chevota guys? Even though I'm not a Chevota....

If that's the case, could I have slowly fried my clutch and killed my TO? :mad:
Any chance you have a leak that is getting on the clutch causing it to slip?
Think of the path the oil would have to travel through to get to the clutch disk.

That darned flywheel makes it tough ;)
No leak...I just got the insp. cover off again and started poking around.

First off, if my truck is just sitting in gear, turned off, I should be able to spin the TO bearing, right? The TO should only touch the fingers with the clutch depressed, right? The TO has definite resistance in this position, not much, though. How space should there be between the TO and the fingers? Could the fork and related parts need cleaning and lubing to work better?

Anyway, I'm not a master mechanic, but I'm hoping that this may only be an adjustment?

Thanks for the help.
Oh well....I got in there and reset all the adjustments to factory specs for the pedal height/throw, etc... and the slave for its clearances...made sure the TO bearing was not sitting on the fingers and clutch throw looked great. Definitely felt great, adjustment wise, but she was still slipping under hard acceleration...

Time for a new clutch...:frown:
Any advise on the best kit? quality and price? Oem, obviously..
Sorry. No advise on a kit.

But I can say that a leaking seal on the front of the transmission of a stock BJ40 will feed the oil directly into the centre of the clutch so that it immediate covers "friction pads" in oil. (I replaced my front transmissionj seal at 40,000kms due to this and modified the "nose" to prevent it happening in the future - by drilling a drain hole away from the clutch.) I would think an FJ40 is likely to have a similar design-flaw.

And one should always have the "play" adjusted to specifications to prevent premature clutch failure.

That "freeplay" before the slave makes the TO bearing hit the pressure-plate-fingers is vital!

Leaking front transmission seal can do that.

Most leaks in the clutch area are from the rear main/oil pan seals tho. And they really cannot get to the clutch.
I wish I could just change out the front trans seal, and while there is oil behind the inspection cover, it doesn't appear to be near the clutch area itself, not even on the TO bearing...probably just the rear main leaking and working it's way backwards...

Can you check the clutch disk thickness from under there? I tried shining a flashlight in there but could really see much. I'll go snap a pic and show you guys the area....
If the T.O. Bearing was not returning to home base when your foot was off the pedal, that would have the clutch partially disengaged while you are driving, consequently the disc slipping, heating up, and self destructing---possibly in slow motion. Exactly the same thing would happen if your slave was not adjusted properly, the T.O. was "always" riding on the pressure plate fingers leaving them somewhat depressed. Bottom line, you could have already fried a disc.
Now for the product pimp; your stock clutch has a 882 lb. clamp load, the Centerforce has a 900 lb. to 1200 lb. clamp load, the Downey has a 1400 lb. clamp load, and most of the other choices exceeds the capacity of your slave cylinder (and thrust bearings) and should not be used. If you need further explanation as to why you need maximun clamping pressure "off the line", PM me for the details.

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