A few months ago I had the clutch/pressure plate/flywheel/throwout bearing replaced because there was a high-pitch squeal when taking off from a stop. This noise occurred only at the clutch friction point. Well, the noise is back.

From what I have read the original source of the noise was the TOB going bad. After having the clutch/PP/FW/TOB replaced by a reputable mechanic I don't understand why the squeal has come back. I have read that the input shaft bearing is sometimes to blame but the typical ISB symptoms just don't fit. I have replaced the slave cylinder, the master cylinder is bone dry, and the hydraulic pressure is good. Aside from the obnoxious squeal, the clutch assembly performs perfectly. Like most people with this problem, it occurs most often when engaging the clutch on a hill or "feathering" the clutch from a stop. I am pretty sure the squeal is related to the TOB, but I am beginning to think this problem is merely a symptom of another issue. Can an internal tranny problem cause TOB failure symptoms? The only symptom I have which points to the tranny is a mild shimmy at low rpms upon acceleration. This shimmy has been there since I purchased the vehicle and I perceived it to be an unrelated harmonic vibration. But I could certainly be wrong. Ideas please!


EDIT...
I just poked around under the hood and found that the release fork has a small range of movement where it meets the slave cylinder pushrod. When I push up and down vertically it feels like a light switch but it rotates only one or two degrees (just enough to feel a click between up and down). The ROM is taking place at the connection point to the slave pushrod; the release fork is pivoting inside the tranny. Can someone go push on their release fork and tell me if this is normal?


Modified by z2weaver at 6:15 PM 9/18/2007

 

+1 im having the same exact problem. at least i have a better understanding of what is causing it.

 

Try putting a bunch of grease into the "dip" in the release fork where the pushrod goes in, you'll need to unbolt the slave cylinder to do this, then just pack the grease in there.

 

Is it a continuous squeal or does it only make noise as you move the clutch pedal?

 

I believe he is describing a sound I've heard other preludes do before in the past. The thing makes a quick chirping sound right at the friction point.

I would again say, grease the fork in that little hole, it will be vibrating very vigorously right at engagement and it could be squeaking against the end of the pushrod.

 

The squeal occurs only at the clutch friction point. No noise otherwise.

I am pretty sure the squeal is coming from the tranny side of the release fork (not at the slave cylinder connection point). But the play at the slave cylinder might be causing the release fork to vibrate which makes the clutch squeal. Again, can someone go push on their release fork and see if there is any play. I would like to be sure that mine is different than others before I go taking it apart. Also, I am not so sure that grease will make a difference. Grease will lubricate the pushrod connection point but it won't eliminate the play which I think is allowing the release fork to vibrate causing the noise inside the tranny.

 

Can someone please go push up and down on their release fork where it connects to the slave cylinder pushrod and tell me if there is any play? As my previous post indicates, I feel a tiny bit of play and it behaves similar to a light switch. If a couple of people tell me their release fork is solid as a rock where it connects to the slave cylinder I will know I've got a problem here.

Thanks!

 

Bump

 

I just took a closer look at the slave cylinder connection to the release fork and the play is actually all in the slave cylinder pushrod. The connection between the SC and the RF is rigid after all. The play I feel is the pushrod pivoting inside the slave cylinder housing. When I push in on the release fork and shove the pushrod back up into the slave cylinder the vertical play is much worse. I tried greasing it up like someone suggested with no luck. Again, can someone please go out to their car and fiddle around with your release fork. I am beginning to think nobody actually owns a 4th gen Lude out there.

Here's what you do. Go outside, pop your hood, and push up and down vertically on the end of the release fork where it meets the slave cylinder. Do you feel any range of movement here? Next, push the release fork toward the slave cylinder to depress the pushrod. With the pushrod depressed push up and down on the release fork. Does the range of movement get a lot worse? I am trying to determine if it is normal for the pushrod to wiggle around inside the slave cylinder.

Thanks!

 

That motion you describe is normal. The release fork just pivots on a spherical bolt and is pushed by a spherical rod end from the slave, so it's free to pivot in any direction to apply even force on the throw out bearing. There is a light spring inside the slave cylinder to take up the slack, but that is also free to move in/out.

If you are just getting a creaking sound as the clutch fork moves, it could need grease on the spherical bolt inside the bell housing, or it could just be the diaphragm spring in the pressure plate. Either way, it's probably not worth taking the thing apart.

If you get a continuous squeal, then something is not right. Bad throwout bearing, slipping clutch, something rubbing, or worse: the flywheel bolts could have backed out and are rubbing on the clutch disk.

 

flyrod, you are the man. Thanks for the clarification.

Unfortunately, this means I've got a bigger problem. From time to time I get a "creaking sound" when I depress the clutch and move the release fork, but I don't really care about that. What I am experiencing is evidently clutch squeal. Right at the friction point I am getting a high-pitch squeal. But like the thread title implies, I have replaced all of these components. Assuming everything was properly lubricated, what could cause these symptoms which are normally associated with a bad TOB?

Thanks!