Clutch Still Squealing!

[Opelotus]

About 500 miles ago I did a clutch job on my 928 after the TO bearing siezed and broke some of the fingers off of the pressure plate, causing the slave cylinder pushrod to pop off the fork. Parts I replaced are as follows:

TO bearing + washers
Pilot bearing
flywheel bolts
pressure plate
clutch disks
resurfaced original flywheel
resurfaced original intermediate plate

I didn't replace:

guide tube
release fork
splined shaft

I followed all the WSM instructions, used Hi-temp grease, etc.

Ever since the new clutch was installed, there is a squealing when I begin to engage the clutch, but only when starting from a standstill (when the clutch slips the most). There are no vibrations felt in the car/clutch pedal during engagement. The noise disappears completely once the clutch is fully engaged. Before the old clutch killed itself, there was a SMALL squeal during engagement, but not as noticeable as the new one (old clutch was also dragging). Is this an issue with the clutch, or could it be the torque tube? Any help would be greatly appreciated, it is really annoying and somewhat embarrasing driving around with a squealing clutch.

[JhwShark]

If the noise is consistent could be TT, it would get louder as you accumulate miles on it; doesn't seem to be this from your description.
If the noise is only during clutch engagement...grease/oil on disk or bearing?? low odds since new.
The new release bearing is sound and clean, not bad???
Maybe just need to spin the new parts in, driving a lot; I hope not, shouldn't have to?
Bummer, I wouldn't like it if my manual tranny cars squealed shifting!
Jon

[Opelotus]

I have been leaning toward the idea that the torque tube is causing the noise, only because the noise did exist (although not as noticeable) before I installed the new clutch kit. Unless it is one or more of the parts that I did not replace that are causing the noise (or flywheel/ int plate not machined correctly???). Only issue is that it doesn't sound like the kind of noise the TT would make, unless the bearing is going, but again it only makes noise during engagement, which brings me back to the clutch I already pulled the clutch out a second time, and cannot see any signs of oil/grease on any surfaces, both the flywheel and int. plate still have a bit of the machining pattern left on them. I tested the T/O bearing when I removed it the second time, put it up against a buffing wheel, got it spinning at ~1500 rpm, no noise.

[Mrmerlin]

how much was cut off of the I plate??
please post pictures of your clutch this might help with a diagnosis
The other possibility is that one of the alignment dowel is pushed out the front side of the flywheel and its hitting the bell housing,
or one of the clamp bolts may be hitting the guide tube mounting area this will require removing the lower bell housing to check the parts,
also look for the clamp bolts hitting when the drive shaft is turning

[Opelotus]

Don't remember off the top of my head how much was cut off the intermediate plate, but I gave the machine shop the spec for its minimum thickness as found in the WSM, and I was told upon pickup that it was still within spec after it was machined. Same goes for flywheel. Unfortunately I only have photos of the clutch kit and some of the reused parts if you think they will help, I somehow failed to take photos of the int. plate and flywheel when they were out of the car. Could int. plate misadjustment cause such a noise without also creating vibrations?

[LUFTMAN]

I have a new guide tube i can give you if that will help? Regards tom

[Opelotus]

A new guide tube couldn't hurt. There was slightly more wear on one side of the original guide tube as compared to the other side. But could a worn guide tube actually cause a squealing? I suppose if the TO bearing was off-center due to an unevenly worn guide tube, a squealing could possibly be created. I really wish there was a way to actuate the clutch release lever with the bell housing cover off.

BTW is there a trick to replacing the guide tube without pulling out the engine clutch assembly? If I do replace the guide tube I would hate to have to remove the entire thing a third time.

[Mrmerlin]

I think your going to have to remove the whole clutch package to replace the guide tube

[Opelotus]

If/when I get a chance to pull it out again, I will be sure to check the flywheel/intermediate plate for flatness/runout. I just hope I can borrow a lift next time, it's a bear to do on your back.

[vandenham]

Opelotus, I have been having a similar problem, but it is not a squeal. It is more like a rattle/clunk when I first start to engage the clutch. And I have some chatter/vibration when the clutch engages.

Like you I replaced everything in the clutch assembly excluding the release fork, splined shaft and guide tube. The noise and vibration reduced slightly but did not go away so I thought it must be caused by bad bearings in the torque tube. Just finished installing new bearings in the torque tube a couple of days ago and the noise/vibration again reduced but did not go away.

I am now beginning to suspect the guide tube. It was shiny on the inside when I looked at it during the first clutch replacement but I did not think anything about it.

It is called a guide tube, but is it supposed to come in contact with the drive shaft? I thought it was only there to stop significant movement of the shaft, not to actually touch every time the clutch was released. Is it possible that the release fork is lifting the throw-out bearing off centre causing the shaft to push/rest against the wall of the guide tube until the clutch starts to re-engage?

This is a frustrating problem, but I am getting very proficient and removing and re-installing the clutch.

Rick

[Opelotus]

Yes I suppose it is possible that the release fork is pulling the bearing off-center. I had the same thought, as my guide tube was slightly worn on one side of the outer circumference. Pretty sure it is not supposed to come in contact with the drive shaft as this would most likely make some awful sort of noise. Have you replaced the clutch pilot bearing in the back of the crankshaft?

I also have a clunk when releasing the clutch, notice it most when in stop-and-go traffic, letting out the clutch, depressing it, and letting it out again. It is definitely in the driveline, as far as I can tell it is the back of the transaxle or the cv joints. It sounds to me like the CVs may be worn, and the knocking is caused by the driveline being loaded up and all the play being taken up suddenly. I can also hear what I think is the same noise if I gently let off and then get back on the gas, causing the driveline to go from engine driving wheels to wheels driving engine and back, which further proves the driveline/CV play. I wonder what difference a standard single disc spring dampened clutch would make in this situation.

[vandenham]

The noise in my car only occurs when I start to let out the clutch. I cannot hear any clunk when I release and then step on the gas. I just bought a stethoscope and plan to 'listen' to the car when the clutch is released. This should verify whether the noise is emanating from the clutch, torque tube, transmission or differential.

The WSM says that you should grease the inside of the throw out bearing and outside of the guide tube. I'm afraid I did not do this - I now see that the purpose of the guide tube is to make sure the throwout bearing stays centred. Those two surfaces probably come in contact as the clutch engages as there is a lot of stress on the throw out bearing when the clutch disks start to engage with the pressure plate. That is probably causing my noise and it could cause a squeal too if the two surfaces are not lubricated.

[Opelotus]

Hopefully that is the source of the noise in your clutch. Make note though that the part of the throwout bearing that contacts the guide tube does not spin, it merely slides back and forth over the guide tube. That's not to say that if the throwout bearing vibrates it will cause a squealing noise against the guide tube. BTW did you have your flywheel and intermediate plate machined?

[vandenham]

I believe that is where my noise is coming from and suspect that if I lubricate the parts properly my problem should finally go away. I know that the throwout bearing just slides on the tube, but I think the end of the bearing (facing the flywheel) does actually spin. Where the bearing attaches to the pressure plate with the thrust washer and snap ring it must be spinning. I wonder if that part is spinning near the end of the guide tube and maybe squealing. That is the only part I can think of that might rub metal to metal.

I had my flywheel turned and managed to find a NOS intermediate plate. I took my IP to several machine shops here and they all said they could not machine it unless it was taken apart. That did not seem like a good idea so I hunted around and found a 'new' one.

[Mrmerlin]

FWIW I dont think that cutting the I plate is a good idea as it takes away clamping force from the pressure plate, this would be similar to having worn discs the external area of the I plate spaces the pressure plate a certain distance if you cut the internal surface there will be less clamping force available.
Note the TOB is spinning at engine speed , it never stops unless the engine stops.
The pilot bearing spins when the clutch is pressed down and then the drive shaft is spinning at a different speed or stopped.

If you have an original thickness I plate then its possible you may have put the spring washer in the TOB assembly wrong,
it should go on the back side of the PP fingers and the ID part should have been touching the TOB inner bearing area, the OD part would be fitting against the PP fingers.
Note the 928 PP is pulled to the rear of the car to release as well as the TOB