my truck just developed a squealing noise that continues when the engine is idling in neutral or when it is engaged and driving. The noise stops as soon as I push in the clutch. It's a high pitch squeaking that gets louder as the engine revs. Any ideas what that might be?

Idler pulley bearing?

Don't know why it would stop when you put the cluch in, tho...

Throw out bearing.

>>>*Ditto...Unless....

*Check for thrust bearing wear, it could be rubbing behind the front pulley if the shaft is moving. Stepping on the clutch loads the shaft forward and could stop the noise.

Hook up a timing light, have someone step on the clutch as you shine it on the vibration dampner. See if it moves forward then back as the clutch pedal is operated...*EB

The throw out bearing operates when the clutch is depressed.

Sometimes putting your ear to a long screwdriver touching the block can help you isolate noises. Is it in the front or rear of the motor?

the noise is in the front of the engine: it sounds like one of the pulleys. Is the front pulley located below the crankcase pulley? And I'm looking for movement when the clutch is depressed, correct?

If it is the thrust bearing, how long does that take to replace?

Thanks for all the help.

to my knowledge, none of the pulleys on the front of the engine have anything to do w/ the clutch being pushed. usually when there is a noise that changes when the clutch is depressed it will come from the back of the engine.

Engine Works 101 is in session...

The reason the crank stays in one place no matter what force is applied is called the thrust washer. There are 2 in the 22R series engines, one to hold it forward, and the other to hold it back.

If one or both are bad, the crank can walk forward and backwards if longitudinal force is applied. Depressing the clutch presses the flywheel forward, and can cause the crank to push outwards if the thrust washers are bad. Upon release of the pressure the crank will slam backwards, and usually past the starting point. This can cause the dust shield on the back of the crank pulley to rub against the oil pump housing. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Are you *sure* the squeal is comeing from the front of the engine? If not, sure sounds like bad input bearings on the transmission, from your original description.

Dave

I ran around the engine with a screwdriver to my ear testing sounds last night. The sound is coming most strongly from around the intake manifold (on the passenger side of the engine really- I could only get the screwdriver on the manifold to test it) rather than the front of the engine.

Even the slightest pressure on the clutch will stop the noise- it doesn't have to be fully depressed. The noise gets louder as the engine revs up.

(I checked the pulleys with the screwdriver and couldn't find the sound).