Help I hear whinning!

[vettej1]

Hi all, need some advice. I can hear a whining sound when cruising at any speed. It was like that when I got the car last May. I didn't worry too much about it because I figured it was the rear wheel bearings which I was planning to replace with the new T arms, spindles, ujoints, spring, etc. last winter, which is all done.
But I still hear the sound. I did inspect the diff. when I replaced everything else and all looked very good no gear wear and the bearings felt good. Could one of these bearings be bad??

It does seem like a gear kind off noise, from the rear. (I have a 4 speed.) What am I missing here?

-john

 

[Yoda]

John,

Check the transmission fluid

Does it seem to whine more in any perticular gear.. e.g. second, third etc.. Noise travels through and around the drive train and what sometimes sounds like it is coming from the rear end may be coming from other parts of the drive line

You should be able to take the small square headed plug off the side of the trans, and be able to touch the fluid with your little pinky.. then check it out for smell and what color it is and any metal components.

Good Luck
Bud

 

[SwaveDave]

Could it be your wife ?!

Give us some more clues ; is it louder under heavier acceleration, around turns, go 50 mph and put the gearbox in nuetral...make any difference ? Does it occur when your backing up ??? Does it occur at idle when you rev the engine ?

(enquiring minds want to know.....)

Dave

 

[vettej1]

Could it be your wife ?!

Bud,
I will check the tranny fluid tonight.

Dave,
That's a negative on all except going 50mph and putting in nuetral, I'll try that tonight as well.

Thanks guys!

-john

 

[vettej1]

Ok, tranny fluid is at proper level and looks good.

The noise, whinning, does not change with reving the engine. No noise when car is not moving. Can't hear it with the top down. It changes with the speed of the car whether in any gear or not. At speed with car in neutral I can still hear it.

Rear end??

-john

 

[ironmoo]

I'd suspect the rear-end.

Is the fluid level okay?
My current one was whining at 40 mph+ in any gear. I pulled the differential oil plug, found it was a bit low when I put my pinky finger in. Topped off with new fluid and ...no more whine!

However...The previous differential was whining, but with the fluid levels A-Ok. Hmmmm. Then one evening I looked at the car and did a double-take...The both rear tires where starting to toe inwards (at the top) along with the whine getting louder! Within a day, it was off by almost 2" slanting inwards. Nice way to wear out the new tires!

In my case, had about 170,000 highway miles on the original rearend, so I figured it did not owe me anything and a rebuild was done.

I'd suggest on keeping an eye on the alignment of the rear tires, it could be another indicator of the problem.

Good luck on trouble-shooting process.

-Moo

 

[92ghost]

You may be able to isolate the source by jacking the back end up, and putting it in gear. Have someone in the drivers seat to slowley increase speed while you are underneath listening and observing. I highly recommend you exercise safety when doing this for obvious reasons. Two jack stands - one on each side, a floor jack under the diff., and blocks of 4x6's stacked just high enough to slide under the frame. Oh... and don't touch any spinning parts while under neath.

Good luck and be safe...

 

[Culprit]

I have only had my Vette a month so I can't speak from experience, but...

Many people advise to never put the car in gear with the rear end up in the air. With the weight off the rear suspention, the angles in the u-joints on the half-shafts are greater and it causes more stress on the system.


Culprit

 

[SwaveDave]

If you have a posi rearend...you did put GM Posi additive in it,right ???

My guess is that the whine its originating from the rear end.

Dave

 

[vettej1]

If you have a posi rearend...you did put GM Posi additive in it,right ???

Dave, yes I have a posi rearend and when I put the new HD cover on I put new GM lube and additive in.

-john

 

[Bob Chadwick]

You may be able to isolate the source by jacking the back end up, and putting it in gear. Have someone in the drivers seat to slowley increase speed while you are underneath listening and observing. I highly recommend you exercise safety when doing this for obvious reasons. Two jack stands - one on each side, a floor jack under the diff., and blocks of 4x6's stacked just high enough to slide under the frame. Oh... and don't touch any spinning parts while under neath.

Good luck and be safe...

This is not recommended by Stingray6974, one of our more knowledgable members.

Under NO circumstances ever jack up a vette rear end and spin the tires with the engine. The extreme angle of the halfshafts forces them against the inner yokes. The damage will be extensive and possibly deadly if a u-joint breaks...Mike

 

[vettej1]

You may be able to isolate the source by jacking the back end up, and putting it in gear. Have someone in the drivers seat to slowley increase speed while you are underneath listening and observing. I highly recommend you exercise safety when doing this for obvious reasons. Two jack stands - one on each side, a floor jack under the diff., and blocks of 4x6's stacked just high enough to slide under the frame. Oh... and don't touch any spinning parts while under neath.

Having recently rebiult my rear suspension over the winter I have learned quit a bit about the "physical limits" of all the parts that work together back there.

Thanks for the suggestion, but this is something that I wouldn't recommend either.

-john

 

[CS72Roadster]

Last night having completed a rear spring replacement and half-shaft u-joint replacement, I would agree and advise; do not enagage the drivetrain with the rear wheels hanging. If it ain't broke beforehand, it will be when you finish. The IRS is not the same as a straight axle that itself can be supported with jackstands and allowed to turn under power.

Be safe.

CS

 

[92ghost]

I stand corrected. I had no idea jacking up the rear and putting it in gear would do such harm.