[jcarey8]

Origionally a 72 chevelle with 350 motor, TH350, 2.73 RE gears. Converted to manual muncie m20 (with supercase) 3 years ago. I rebuilt muncie due to broken ear hense the new super case, did not replace syncros though before i installed it. Not many miles on new clutch/conversion pieces.

Also 2 years ago replaced the 2.73 RE gears with a limited slip 3.43 gears not the smoothest conversion but a knowledgeable old timer set it up and had no problems since.

Last summer is started to develope a whining noise that always appears once the car is warm and happens while crusing 35mph-70mph when drivetrain is floating (engine and wheels are matched not accelerating or deccelerating).

Does not happen when crusing at a speed and shift it into nuetral and realease the clutch or when the clutch is engaged/ depressed.

Pulled the tranny oepned it up gear oil does have a silver metal flake paint look to it but cant find any wear with entire tranny taken apart.

Throw out bearing has a tiny tiny bit of looseness/play and spins very well (spin it and it continuse for 3 seconds).

I was sure the noise was coming from the clutch set up but at this point willing to test anything. ANY IDEA WHAT THE HECK IS PRODUCING THIS WHINE?

 

[jcarey8]

Could it just be the clutch is not adjusted correctly and its causing the throw out bearing to continuously spin and thats why the second I depress the clutch even a little it goes away... but that wouldnt explain why it goes away when under either acceleration or decceleration would it?

 

[MEJ1990TM]

Could be the roller bearings in the transmission. The four speed in the '71 has bearings that are starting to go. Just at that precise throttle it starts to make a little noise. Of course I can't hear it in 1st, 2nd, and 3rd because of the gear whine, but in fourth I can hear bearing noise. You say you have the transmission apart. With the bearings washed ,and dried, do they feel rough, or make extra noise?

 

[estherkilledfred]

Hmmm...

Extract your current pilot bearing.

Is it by chance...a roller bearing unit?


Regardless, put in a fresh (Kevlar or AGE) non-roller pilot bearing. :thumbsup:

 

[estherkilledfred]

Like these even better than the bronze. :yes:

http://www.competitionplus.com/drag-racing/new-products/13027-ram-kevlar-pilot-bushings-


Never ever even "think" about a roller pilot bearing! :noway:

 

[Verle]

Never ever even "think" about a roller pilot bearing! :noway:

GM has used millions of roller pilot bearings over the last 15-20 years.
I suspect if there was a major problem they would have changed back.

 

[jcarey8]

When the engine and the transmission are matched (floating) wouldnt the clutch be solid so the pilot bearing would not even be spining since the traanmission input shaft is spining at the same spead as the crank shaft?

The bearings all feel litereally brand new.

 

[MEJ1990TM]

Any time the clutch is engaged the input shaft of the transmission is spinning the same sped as the crank. The only time you would notice a noise because of the pilot bushing is when the clutch is disengaged.