Noises coming from throwout bearing..
 

Its a '69 with a 3 speed column shift. I just replaced the clutch, plate and throwout bearing 6 months ago. The throwout bearing is making a grumbling, growling type of sound. you can also feel it throught the clutch pedal.
The old throwout bearing made the same type of noises, but not as much as the newer bearing.
My first thought was the clutch adjsutment was wrong. However, it doesnt seem to change the problem no matter where I adjust the clutch. The noise only happens when I am engaging/disengaging the clutch.

Has anyone experienced this before or know what is causing the bearing to do that?

Re: Noises coming from throwout bearing..
 

When you adjust the clutch, is there free-play in the pedal....such as pushing the pedal down, feeling the bearing hit the pressure plate... then the release of the clutch. OR just pushing the pedal down with a solid feeling?

Re: Noises coming from throwout bearing..
 

You should have an inch or a little more of free travel with the pedal before you feel the throwout bearing push against the fingers on the clutch. If there isn't any slack, the bearing will be spinning all the time an wear the bearing an the clutch it's self.

Re: Noises coming from throwout bearing..
 

Probably another bad throw out bearing. Make sure that you have some free play as kwmech mentioned but parts are not made like they used to be. Too many foreign manufacturers that flood the market with cheap parts and we have no recourse but to buy them.

I had the same thing happen some years back. Mine was noisy but worked ok so I just left it.

Re: Noises coming from throwout bearing..
 

I beg to differ! I'd bet money (if I had any!) that it's the pilot bushing... especially if it's not changing with the clutch adjustment. I've had a couple brand new pilot's go bad on me and it makes a similar noise.

Re: Noises coming from throwout bearing..
 

If it only makes noise with the clutch down, I would say thowout bearing.......if it makes noise in nuetral, with the clutch up, I would look @ the pilot bushing, or possibly the front bearing in the trans. ;) when the clutch is up(properly adjusted as mentioned in above threads), the throwout should not make any noise. crazyAl

Re: Noises coming from throwout bearing..
 

There is about an inch and a half of free play before the bearing contacts the clutch fingers. There is no noise while the clutch is engaged at idle or while driving. It doesnt make the noise every time i hit the clutch. its more prone to do it while i am downshifting or manuevering (sp?) in dirveway/parking lot. it doesnt seem to make the noise at any specific point in the clutch travel either. it doesnt do it at the top or bottom of the pedal travel but it does it sporatically in the middle of the clutch pedal travel.

My first thought was that is was another bad throwout bearing. but it didnt make sense that it started back making the same noise not long after installing the new clutch. I tore up my transmission last summer and installed a new transmission, the new clutch including the pilot bushing. The only thing that remained the same was the bellhousing and clutch fork assembly.

I am not ruling out a bad bearing. How does a pilot bushing go bad? Worn out?
How far front to back should the pivot ball move? Could something in the clutch fork assembly be bad causing this? i dont want to take the transmision out unless i have too.

Thanks for the help guys.

Re: Noises coming from throwout bearing..
 

I had a guy do a clutch for me a while back. 2 weeks later, all hell was breaking loose so I brought it back to him. He cracked the pilot bushing when he was installing it. So that is a possibility of what could go wrong.

Re: Noises coming from throwout bearing..
 

Since the same problems exsits with both the old bushing and the new pilot bushing, its not making sense that its the pilot bushing. The only time the pilot bushing is "in use" is when your pressing the clutch, so it does make sense that it could be the bushing. But if the pilot bushing was bad wouldnt it make noise throughout the pedal stroke and also make noise everytime the clutch was used?

When I swapped the tranny and clutch, i was paying close attention to the bushing, the bearing, the input shaft bearing and the input shaft housing because i had been having this problem before. I cleaned the input shaft housing to make sure there was not a bur or scratch causing the problem. I spun the pilot bushing on the input shaft to ensure the fit. The bushing slipped right into the flywheel, didnt have to be pressed in. The new bearing spun smoothly and was well greased when it was installed.

This is why I am looking more at the clutch fork and pivot ball stud. But i dont know how much adjustment the pivot stud should have and i dont know how much play the fork should have. the pivot ball will only move forward/backward about 1/8 of an inch before it seems to bottom out. The fork has some wiggle to it, but how much is too much?

Re: Noises coming from throwout bearing..
 

Uhhmmmmmmmmmmmmmm. the pilot bushing is supposed to PRESS into the back of the crankshaft

Re: Noises coming from throwout bearing..
 

Yes - I think kwmech is correct - the pilot bushing should press into the flywheel. Once had an odd situation where a PO had installed an auto trans flywheel on a three speed manual Dodge of some sort. When I re-did the clutch, the bushing supplied for the 4sp trans would not go into the flywheel. Bought a bushing for an auto trans and it pressed in correctly - fortunately the bushing ID was the same for both trans shafts.

These things do get mixed up, even by the manufacturer. If the pilot bushing is at all sloppy in the flywheel, could be the problem.

Re: Noises coming from throwout bearing..
 

I agree, it should be a press fit in the crank,& is most likely the problem. There were (at one time) 2 different sized bushings listed. 1 bushing fit the stick shift(factory equipped) vehicles,& 1 was listed for an auto to stick shift conversion. There is approx .030 difference in the OD of the 2 bushings......& I have run into the problem several times over the yrs. It sounds like you need to tear her back down. Best of luck,crazyAL:chevy:

Re: Noises coming from throwout bearing..
 

THE BUSHING PRESSES INTO THE END OF THE CRANKSHAFT!!! NOT THE FLYWHEEL. sheesh

Re: Noises coming from throwout bearing..
 

Correct me if I am wrong, but automatics use flex plates with torque converters, not flywheels...at least not one that could be used with a clutch.

Generally replacing the pilot bushing is a standard procedure when you replace the clutch. I know from experience if one is bad the other will go out shortly after. You also want to consider the replacement clutch depth and your throwout bearing collar. With Datsuns there are a couple of different sizes....I am new to Chevys, but that could be something to consider. Like it was mentioned before, if the bearing is spinning all the time it will overheat and go bad quick. ;)

LOLZ!!!

Re: Noises coming from throwout bearing..
 

You are correct. the bushing does go into the crank not the flywheel. my mistake. thanks for pointing that out.

And let me reword what i wrote earlier. when i said it slipped in. there was no slop or play, but it did not have to be beat in with a hammer like the one i had to remove. i greased the hole and pushed it in. it took some force but it didnt just slide in on its own. slipped was a pour choice of words. sorry. I made a point to take note of all those clearances. And again, i am not saying it is not the pilot bushing. This is my DD so i cant afford to take the trans out until i know the problem.

The old pilot bushing had to be tapped and pressed out with a bolt to remove it. the same issues exsited then. The clutch i replaced it with was warranteed, so it was the identical clutch and throw out bearing. I also removed the front input shaft bearing and took it to the store and it spun just as smooth as a new bearing. The transmission came from another board member and had recently been rebuilt, so i decided not to replace that.

At lunch i drove it and played around with the clutch trying to pay attention to when it was doing it. It doesnt do it on the down stroke of the pedal. it will only do it when you are feathering the pedal. like when backing or driving slowly in a parking lot.... moving the pedal in and out at low speeds. when the noise starts, you can move the pedal in or out slightly and the noise stops, only to happen again until the clutch is either engaged or fully disengaged.

Re: Noises coming from throwout bearing..
 

An old trick to getting those out is using heavy grease in the crank hole where the pilot bushing sits, then use a dowel and hammer to push into the hole, using the hydrolic pressure of the grease to push the old one out. :)


Maybe the throw out bearing is defective.

Re: Noises coming from throwout bearing..
 

I havent ruled out the throw out bearing yet either. but if it is the throw out bearing, why have two bearing gone bad the same way? Why did this bearing go out so soon? Then, what is the bigger problem causing the bearings to go bad? Same question if its the pilot bushing thats the problem.

I dont want to tear it down, again, replacing the throw out bearing and pilot bushing, just to have it go back to doing the same thing. i am getting a repetitive problem with clutch replacements, that is telling me that the problem is not in the clutch itself. Something else is causing them to go bad.



the grease and dowel trick didnt work on the previous bushing. i really had to drive that one in, i knew it wasnt coming out without a fight. however the new bushing will pop out with the grease and a dowel.

Re: Noises coming from throwout bearing..
 

didnt know there was a clutch on an auto lol

Re: Noises coming from throwout bearing..
 

Could be worn input shaft bearing on the transmission to give the growling noise. We've had 2 of the 3 speeds where the input shaft would wobble. One transmission would growl with a load on it, the other one I can't remember. HTH.

Re: Noises coming from throwout bearing..
 

I had a trans am that ate up throwout bearings.Turned out that the clutch fork was bad.I put a new one in no more problems.