transmission bearing noise

[8cam]

My transmission has always had the "rocks in a can" noise with the clutch engaged - disengage it and it gets quiet. But this is a new noise, I heard before on a couple rare occasions but just today got really frequent, like almost every trip through the gears. It's a loud whine/growl (fairly low-pitched) that is momentary, when I disengage the clutch and shift. It seems to happen as I'm either leaving one gear, or going into the next gear. Once in gear, or in neutral, and it's gone. It doesn't happen on every shift, but happened on a bunch right at the end of a 250 mile journey this afternoon. Does this sound like a throwout bearing going bad?

[8cam]

I should mention the transmission shifts smooth, solid and tight, no issues. And the car accelerates just as strong as ever, so there's no clutch slip going on either.

[LGAFF]

Is there a change where the clutch is releasing?

[We Gone]

Have you changed the fluid?

[8cam]

Originally Posted by LGAFF

Is there a change where the clutch is releasing?

Originally Posted by We Gone

Have you changed the fluid?

No and no. The clutch is working exactly like normal, and it really still shifts and drives perfectly. Just this obnoxious whirr/growl that happens right at the shift point. I can feel a vibration in the clutch pedal when it happens, so it seems it's right when the throwout is spinning up. Which is why I suspect that bearing is the problem.

I have another 250 mile drive tomorrow morning to get home, and since I'll be spending most of the time in 6th (and minimize shifting) I don't think it will be a problem. Not a job I look forward to doing on the garage floor. I may just take it to a local transmission shop I know does good work.

[A26B]

May be the pilot bearing/bushing.

[Paul Workman]

Originally Posted by A26B

May be the pilot bearing/bushing.

X2 I wuz going to say the same thing; pilot bushing/bearing or throwout...would be my guess, based on the description.

The only thing about removing the drive line on the C4s is the C-beam. One: It should be properly centered to reduce wear and noise on the U joints. Bill Boudreau )at (602) 319-6575) can provide some 48mm and the 28mm gauges for that purpose, OR you can make some yourself, easily enough.



Bill also provides C-beam plates which IMO are worth every penny, especially if you have big hands.

[Dynomite]

Originally Posted by Paul Workman

X2 I wuz going to say the same thing; pilot bushing/bearing or throwout...would be my guess, based on the description.

The only thing about removing the drive line on the C4s is the C-beam. One: It should be properly centered to reduce wear and noise on the U joints. Bill Boudreau )at (602) 319-6575) can provide some 48mm and the 28mm gauges for that purpose, OR you can make some yourself, easily enough.



Bill also provides C-beam plates which IMO are worth every penny, especially if you have big hands.

Yep............got to ALWAYS pay attention to Ole Jerry and Ole Paul
Them guys know stuff

TRANSMISSION
Pilot Bearing
ZR-1 Transmission Install and Lift Tricks
Vibration Issues Diagnosis
Throwout Bearings and Clutch Forks
C4 Beam Plates and Installation

Bill's C-Beam Plates

[8cam]

Absolutely, thank you for the help guys. I drove the car back home yesterday, another 250 miles and everything was just fine. It still made that whirring noise occasionally, but not as frequent. I tried to use the clutch quickly and sparingly, limiting the engagement of the throwout bearing. It was also raining the whole trip back, so I'm wondering if that kept things a little cooler, since it wasn't as frequent. It used to be clattery with the clutch out, quiet with the clutch in. Now it's still clattery with the clutch out, but different-noisy with it in and I get that whirr on occasion.

One thing is for sure, when I get in there I'll be replacing all the wear items - pilot, throwout and clutch disc, and I'll assess the flywheel then. Not really interested in a lightweight like a Fidanza, but something a bit lighter than stock might find its way in there, depending on budget and wifely tolerance.

[LGAFF]

When my Throwout went South it made a similar noise, but the release moved up as the bearing began to come apart. Sounds like the pilot bearing