The Stovebolt Site Forums The Shop Area Engine Shop Clutch noise

I searched and read the posting on clutch noises and some sound close to what I am experiencing but not quite.

I resurfaced the flywheel and reattached it to proper specs. I then replaced the old clutch plate, pressure plate, throw out bearing and input shaft bearing.

Now, I finally connected the drive line back to the diff. and tried to drive last night. When I let off the clutch, I can hear what sounds like the clutch plate rubbing against the flywheel. It sounds alot like a guy with 2 symbols (like a marching band) and spinning them against each other.

As I said, I have replaced everything. The only thing that I have done that I consider "out of the ordinary" is I adjusted my clutch linkage. Before I connected the drive shaft, I started the motor and with the clutch pedal depressed the output shaft of the transmission was still turning. I pushed my linkage to make sure that when I depressed the clutch pedal the transmission would not move.

My question is: does this sound familiar to anyone? Could my linkage modification cause the clutch to "chatter"? I am ready to drive this beast but I cant do it until I know that I am not going to ruin it.

Thanks for all the help!!!

Tom

Are you sure the clutch plate is not installed backwards ? The center snout on the plate should face forward, away from the throw out bearing..

You could have the clutch linkage adjusted too tight. The noise could be the throwout bearing riding on the pressure plate fingers even when your foot is off clutch pedal. If the tranny output shaft is not hooked to driveshaft, it'll turn a little due to friction between tranny input shaft and pilot bushing, and maybe a little friction between disk and flywheel. The way I set the clutch in my 54 is to have about 1" of play in pedal before clutch linkage starts to work. I also spin TO bearing by hand to make sure its not jammed against pressure plate.

good luck

chip

Is your driveline a two piece set-up?
Does it have a center support bearing(carrier bearing)?
Also like Bill mentioned, it could be the clutch plate installed backwards (clutch plate rubbing against the flywheel)
Does the noise occur while moving or sitting still?
Is the noise constant?
What rig is this you are working on?

I am working on a GMC 3/4 ton with a 270 il6 and Muncie SM420, 2 piece drive shaft with center carrier. The noise occurs when the clutch pedal is released. The intensity of the noise does change during relase; as you let out farther it seems that the noise gets milder. When in neutral, the noise is very quick; when in gear the noise starts loud and fast and seems to get slower and lighter as the clutch engages the flywheel. I installed the clutch plate with the side that said "Flywheel" facing the flywheel.

I actually laid in bed thinking about this alot last night and what I recalled what that before I adjusted my linkage, I could depress the clutch and then let it out and not hear anything, however when the clutch pedal was pressed the trans. output was still turning. I adjusted the linkage and the Trans. output shaft quit spinning when I pressed the clutch pedal but when I release it I get the sound.

I am leaning toward the fact that I may have overcompensated when I adjusted my linkage. Could that have caused what I am hearing? I have about 2.5" of travel for the nuts that allow the adjustment and I bet I adjusted it by 1". I also hooked up a spring that was down under my steering box back to my clutch linkage where the linkage joins the fork arm. I am not sure that this is where it goes, but it was connected under the steering box and hanging loose and I could not find any pictures which tell me where it goes.

So, am I just a bone head or what? How do you think this should be resolved? I appreciate the help!

Tom

Reread Chiphead's post. Pay attention to two things. The transmission will spin without the driveshaft, even in neutral and probably not want to go into any gear. He said "1 inch of play in pedal"

Clutches are not adjusted according by the amount of the thread on the linkage. The idea is to get the throwout bearing just off the pressure plate fingers when the clutch pedal is released. Also to make sure that when the pedal is depressed, the engine is disengaged from the transmission..

Chip is right, a general rule is to have about of inch of free pedal travel before the throwout bearing touches the fingers..When the clutch is depressed the pressure plate releases pressure allowing the clutch disk to move back from the flywheel...

WIthout seeing your linkage it is tough to tell what you did wrong.. Do you have a shop manual to check to be sure the linkage and return spring are installed properly ?

All good points so far,,,
I re-read your first post and saw this which got the tw gears grinding in my head ,,, not much else in there .....

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Originalquote from bluebird,,,
Are these parts new?
OR are they the old ones?
(It says replaced the old pieces) :confused:
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If these parts are used/old, there may be some problem with the throw-out bearing,,,
Just curious

Did you remember to refill the tranmission with oil? Stranger things have happened.