all4c4lt4

I have a 96 CE LT4, under 30K miles and close to bone stock. While the clutch is not engaged, and the car is warm, there is a whinning/humming noise from under the car. If the clutch is engaged or in gear, the noise goes away and it sounds normal. This can't be normal. However the car goes through the gears fine, and there is no slipping. Any suggestions? :confused:

Kdrhpe

sounds just like mine

95vett

My 95 does the same thing. Just a very faint whining or whirring, I think it is normal

:cheers:

CarNDrvr

Throw out bearing is wearing. It will last a while, but the noise will get louder as it wears more. You will need to replace it eventually. That's a fun one!!

ittlfly

tommelton

If you change the throw-out bearing, go ahead and convert to a single-mass flywheel. I guarantee you will never hear that slight whirring again! :)

You will hear the sound of rocks rattling around in a can!

Tom Melton
82 CE
86 Z51 Coupe with ZF6 and SPEC aluminum single mass flywheel and tranny full of rocks

James94LT1

Mine has done this ever since I had the Centerforce installed. Goes away
when you push the clutch in. This has been going on for years. Is that bad?

GRX

Could also be the tranny input shaft bearing....or even the input shaft gear... :eek: With the clutch disengaged (foot OFF the pedal) the throwout bearing won't hum. Press the pedal, and if the throwout bearing is the culprit, then you will hear hum. Good Luck. :seeya

VETTENV

I just turn up the radio a little louder. The ol' timers think that there is something seriously wrong :crazy: They just don't understand :lol:

tommelton

I found if I apply light pressure to the throttle, and let the car idle about 800 RPMs, the noise almost goes away.

I think I will have my idle raised when I finally do a custom chip for my ZZ4.

-Tom

cire96

GR is the winner of this quiz. The rest referencing the throwout bearing as the noise source are bzzzzzz - wrong. The transmission input shaft is almost certainly the noise source. The throw out bearing isn't touching anything when the clutch is released. A bad throwout bearing will only make noise when the clutch is depressed and the bearing is riding against the pressure plate.
As for the input shaft hum, I'd check the transmission lubricant level. If it's good, I'd bet that so are you. Cire96 :D

LSCHMIDT

Mine does the same thing. I thought it was a ZF thing.

PeteL

89 zf whines a little bit. Oil changes are a good thing.

Duntov

Every LT4 that I have heard has this whine. I have heard several, but by no means can qualify that all do this.

On my '95 with the factory installed clutch it was much quieter than the '96 models. I installed a '96 clutch assembly and the noise was just like every other '96 out there.

This is normal. I will gaurantee that it is not the input shaft, as I recently had my tranny rebuilt and blueprinted by ZR51 Performance, http://www.zfdoc.com.

LT4SilverEagle

Cross reference.... http://forums.corvetteforum.com/zerothread?id=333029

Looks liike the ZFDOC has some good ideas. Anyone ever try to fix on their own?

85vetteguy

Mine does it also. I'm glad to hear it is probably not anything to worry about. It sounds common.Guy