Throw out bearing wearing out?

[GREASE FIRE]

i am getting a high-pitched kind of whining sound that is mostly audible above 1500 rpm. The higher the rpm's, the higher the pitch of the sound, and if i downshift the pitch drops.
everything else seems normal - it shifts fine, starts & runs fine, etc.
i showed it to a local person who also has an idi (and is a professional tractor mechanic at the local shop) and i revved it up at neutral while he stood next to it and he seemed certain it was the throw out bearing.

can it go like this for a while longer or will it cause more damage if not dealt with asap? i have about a 1500 mile trip coming up and was wondering if that could cause major problems if not fixed between now and then. Anyone familiar with this?
thanks!
Paul

 

[MIDNIGHT RIDER]

Properly adjusted, the throw-out bearing should not be turning at all until the clutch-pedal is pressed.

If it is making this noise whan the clutch is engaged and pedal up, then the clutch operating system is not alowing the bearing to clear the clutch-fingers, thus spinning it all the time.

 

[RLDSL]

Exactly what MR said. If that thing is touching you need to find a way to adjust it out. Chances are someone replaced a clutch assembly / flywheel with an aftermarket and didn't adjust it. You can get an adjustable clutch rod from Napa for about $11. Your pedal should have about 1" free play before touching the throwout bearing to the pressure plate fingers and it should lift about 1" from the floor before the clutch begins to grab. If it's riding all the time now, you probably have about 2" before it starts grabbing.

 

[Agnem]

Hmm... this is very out of character, but I'm going to disagree with both you guys. The slave cylinder has a spring in it, and this forces the fork to contact the TOB all the time. IF the TOB isn't doing it's thing (being a good bearing), then one half of it is going to spin against the fork or the presure plate causing the singing bearing sound. Pressing against the clutch pedal, increases the friction where the fork and presure plate touch the TOB, and this sufficiently overcomes the friction present in the TOB to allow the two halves of it to spin seperately, and the noise will disappear. I've experienced this problem myself, and I was able to cure it by messaging bearing grease into the TOB with my fingers over about a 1 hour period while laying in the contorted position required to reach the TOB properly. There is a small gap in the bearing that grease can be slowly worked into. The best way to see how is to buy a new one and hold it in your hand, while you feel your old one and push the grease in the gap.

 

[GREASE FIRE]

Mel - did you have to remove the transmission (or other parts) to do this?
thanks,
paul

Hmm... this is very out of character, but I'm going to disagree with both you guys. The slave cylinder has a spring in it, and this forces the fork to contact the TOB all the time. IF the TOB isn't doing it's thing (being a good bearing), then one half of it is going to spin against the fork or the presure plate causing the singing bearing sound. Pressing against the clutch pedal, increases the friction where the fork and presure plate touch the TOB, and this sufficiently overcomes the friction present in the TOB to allow the two halves of it to spin seperately, and the noise will disappear. I've experienced this problem myself, and I was able to cure it by messaging bearing grease into the TOB with my fingers over about a 1 hour period while laying in the contorted position required to reach the TOB properly. There is a small gap in the bearing that grease can be slowly worked into. The best way to see how is to buy a new one and hold it in your hand, while you feel your old one and push the grease in the gap.

 

[david85]

Completely different vehicle, but my saturn has a return spring in the slave cylinder too so I'll side with mel.

Been a while since I had the transmission out of the ranger, but I seem to remember that has an integrated concentric slave cylinder and throw out bearing in one assembly with an exposed spring to operate the same way.

You must be registered for see images

The throw out bearing is a ball roller thrust bearing and idlers for accessory or timing belts use similar sealed roller bearings so I don't see it as being a problem for it to be in constant contact with the clutch fingers.

If it was not like that, then you would have more wear and tear every time you made contact with the clutch pedal because the throw out bearing would have to synchronize from 0 RPM up to crank shaft speed each time (similar idea like tires screaching on a 747 when landing).

Not to mention having extra play in the clutch linkage.

 

[david85]

This is the best image I could find, but its from a GM truck:

You must be registered for see images attach

I would expect others to be similar

 

[Agnem]

No I did not have to take the trans off. Pull the slave, the boot, the fork and the pivot ball. Get comfortable and message that bearing with a greasy hand like you were trying to get it to grant you a wish.

 

[MIDNIGHT RIDER]

No I did not have to take the trans off. Pull the slave, the boot, the fork and the pivot ball. Get comfortable and message that bearing with a greasy hand like you were trying to get it to grant you a wish.

A lot of old-timey throw-out bearings actually had grease tubes that were connected to an Alemite protuding from the bell-housing.