Throwout bearing noise

I have 5sp Tremec with a Luk clutch and nylon sleeved throwout bearing. It's been installed for about 3 years and has about 4k miles. Just over this past winter, I've started getting a squeal from the clutch area any time the clutch is fully engaged. Same type of squeal that you get from a loose/slipping belt. I can hear it at idle with the transmission in neutral and the clutch engaged. When the car is moving with the clutch engaged I can barely hear it, the engine and road noise drown it out or even make it go away.

If I rest my foot lightly on the clutch pedal, not enough to start disengaging the clutch but just enough so the throwout bearing touches the clutch, it goes away. I think it's adjusted correctly; just a little bit of play in the pedal before it starts engaging. Clutch action/engagement is fine; works just like it should.

It's really annoying because it makes the car sound like crap when sitting at a stoplight or in the driveway with the engine running.

What's probably causing this? Thowout bearing? I'd gladly replace it but I hate taking out the transmission and putting it back in just to look or to replace the wrong part.

Thanks!
Brad
 
Re: Throwut bearing noise

Pilot bushing clearance to trans input shaft should be .001 to .004
...with .002-.003 being considered about ideal,and the common brass pilot bearing
brasspilot.jpg

should be greased on install, but manufacturers parts vary and .005-.006 clearance to account for a bit of bell housing miss alignment and heat expansion is common.

yeah sounds like classic symptoms of a throw out bearing starting to fail, or one improperly installed,
but look carefully as I have seen a roller pilot bearing seated in the rear crank flange act in a similar way, and the transmission itself can be making the noise if something internals starting to fail, or your low on lube, ID sure check the trans lube level also
gmtrow.png

keep in mind theres three common throw out bearing heights and youll need the correct height for your particular application to get proper clutch function

THESE RELATED THREADS MAY HELP


viewtopic.php?f=71&t=6258&p=19699&hilit=pilot+bearing#p19699

http://www.horsepowermonster.com/2012/throwout-bearing/

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Last edited by a moderator:
Short story, the clutch just needed adjustment. Long story, the pushrod was bent from interference with "bolt on" tubular control arms.
 
glad you tracked it down and got it corrected!
and thanks for post what you found to be the cause, so many guys don,t bother to do so, and thats not much help to others with similar issues
 
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