Release Bearing or Pilot Bearing

[Cal3000]

When I release the clutch (push the pedal to the floor) from a dead stop, I hear a squeaking/grinding noise and my car wants to stall.
I've done a lot of forum searches around the web and there seems to be a lot of confusion about which bearing causes this noise in this situation.

Any input?

[steve99]

Originally Posted by Cal3000

When I release the clutch (push the pedal to the floor) from a dead stop, I hear a squeaking/grinding noise and my car wants to stall.
I've done a lot of forum searches around the web and there seems to be a lot of confusion about which bearing causes this noise in this situation.

Any input?

we call it a throw-out bearing.
but if clutch not releasing when depressed it likely to be damaged clutch and\or pressure plate unless the bearing is completly ceased. While its apart you might as well replace the lot with an uprated unit if not done already.

[Ultramaroon]

+1^^^ Don't try driving it. Have it trailered to the shop if you're not doing the clutch job yourself.

[cdrazic93]

+2^

[Cal3000]

I really have no choice as I don't have any other modes of transportation during the week. I just ordered a new clutch today and wont be getting it until Wednesday. From my research, it seems to be the pilot bearing which isn't as dangerous as a failing throw out bearing which can damage the transmission.

From what I see with my car, there is no noise after the car launches. Only at idle and launch. So the bearing doesn't seem to be in use when cursing. The release bearing(throw out) is constantly spinning when the clutch is engaged.
The Pilot bearing (seated in between the flywheel) connects to the input shaft. The main purpose is to guide the input shaft. So, when I start the car, input shaft has no rotation, pilot bearing begins spinning, then the pilot bearing is in use. When the clutch is engage, the pilot bearing is not in use, so no sound.

[steve99]

Originally Posted by Cal3000

I really have no choice as I don't have any other modes of transportation during the week. I just ordered a new clutch today and wont be getting it until Wednesday. From my research, it seems to be the pilot bearing which isn't as dangerous as a failing throw out bearing which can damage the transmission.

From what I see with my car, there is no noise after the car launches. Only at idle and launch. So the bearing doesn't seem to be in use when cursing. The release bearing(throw out) is constantly spinning when the clutch is engaged.
The Pilot bearing (seated in between the flywheel) connects to the input shaft. The main purpose is to guide the input shaft. So, when I start the car, input shaft has no rotation, pilot bearing begins spinning, then the pilot bearing is in use. When the clutch is engage, the pilot bearing is not in use, so no sound.

Throw out bearing or thrust bearing is only in use when clutch pedal is depessed its the one that presses on pressure plate fingers to disengage clutch. when clutch pedal is released and your moving in gear it aint used.

see link below, unless we are getting our terminology all messed up due different countries

http://www.ehow.com/about_5456365_throwout-bearing.html

[86to86]

To test throwout/release bearing:


Drive steady speed somewhere quiet

Push pedal part way down, not far enough to release the clutch

Throwout bearing will spin, pilot bearing will not.


(Is that right? My poor old brain can't work very well this morning)

[Ultramaroon]

Originally Posted by 86to86

To test throwout/release bearing:


Drive steady speed somewhere quiet

Push pedal part way down, not far enough to release the clutch

Throwout bearing will spin, pilot bearing will not.


(Is that right? My poor old brain can't work very well this morning)

Pilot bearing spins so the crankshaft can rotate around the input shaft when the clutch is disengaged. Neither pilot nor throwout bearing spin when clutch is engaged.


OP, I strongly advise against driving it but if you insist, learn to shift without the clutch. Refrain from depressing it except to start from a dead stop. This will be your <ahem> crash course in rev matching. It won't last long.

[86to86]

Originally Posted by Ultramaroon

Pilot bearing spins so the crankshaft can rotate around the input shaft when the clutch is disengaged. Neither pilot nor throwout bearing spin when clutch is engaged.

I was referring to that in-between condition where the stationary clutch fork contacts the throwout bearing, but clutch is still engaged and rotating. If the throwout bearing itself doesn't spin smoothly, it will make noise.

But you're right, this one sounds like it's gone too far and OP probably shouldn't be driving it.

[Ultramaroon]

Originally Posted by 86to86

I was referring to that in-between condition where the stationary clutch fork contacts the throwout bearing, but clutch is still engaged and rotating. If the throwout bearing itself doesn't spin smoothly, it will make noise.

But you're right, this one sounds like it's gone too far and OP probably shouldn't be driving it.

Oh, yeah! That makes perfect sense. Then if it starts to squeak or make noise when the clutch is disengaged - pilot bearing.

That's good stuff. Thanks.

[Cal3000]

Originally Posted by 86to86

I was referring to that in-between condition where the stationary clutch fork contacts the throwout bearing, but clutch is still engaged and rotating. If the throwout bearing itself doesn't spin smoothly, it will make noise.

But you're right, this one sounds like it's gone too far and OP probably shouldn't be driving it.

From that, I believe it isn't the throwout bearing. There is no noise at constant speeds during shift. There is noise however when I hold the clutch down too long. The input shaft begins to slow down and the pilot bearing begins to spin.

Release bearing always makes noise when the clutch is engaged if it is damaged.
Pilot bearing makes noise when the clutch is pressed.

[ame="https://www.youtube.com/watch?v=boPbjotHSE0"]Clutch release bearing/throwout bearing squealing noise - YouTube[/ame]

I fear the throwout bearing more as that can disintegrate and get caught up in the transmission and cause failure.

[Ultramaroon]

I've never experienced a pilot bearing failure so I'm especially curious in hearing of the outcome. Good luck with the repair.