nolimits

07 Z06 R6 13K mi etc. had an off, was a tail around spin sideways into the dirt infield. Hi spd, and enough to get rocks way in the outside tire beads. Now I've got a whining sound that goes with driveline gear speed. Not engine, in all gears, much less in neutral coast, is worst under load. Clutch and brakes were put to the floor after correction attempt.

I don't think it's diff. Changed all 4 wheels, no difference, braking makes no difference. Steering swerves to shift weight don't change sound. I'm still thinking maybe I may have jammed a wheel bearing? U-joint issue? I'm going to take wheels off and give the hubs a spin to see if I can feel a bad one.

Any ideas or experiences?

Thanks in advance.

froggy47

You could check your alignment & see if anything is way off.

VTME13

Sounds like it could be a rear wheel bearing. I had a similar issue after an off, but I couldn't track down a single bearing to replace. So, I replaced them all with SKF HD hubs/bearings. No more noise.

Would recommend checking everything out before throwing $1600 worth of hubs at it, though. It could be something simple.

nolimits

I hear ya. The SKFs would be nice at some point when it becomes necessary by choice I hope. I'm going to give the hubs a spin this weekend and check for roughness or anything odd. I was also wondering if drive shaft splines could get damaged, would guess not given they can go in and out some I believe. Maybe a small rock in a u-joint area... I'm hoping to find an easy surprise, ha, didn't think a flat no contact dirt off could cause a problem usually other than rocks in beads & areas etc. I may be about to learn otherwise.

nolimits

Dang, upgraded to SKFs all around but that didn't get it. Upgrade needed anyway. Based on symptoms that was likliest, right rear or rear. So now begins the wild goose chase to find the drive train whine or toss $ all at once and replace several things, ouch. Maybe alignment check, could that really cause a whine?

naschmitz

The gear whine you can hear in this video is diff death noises. You only hear it under power or engine drag.

nolimits

Thanks Bert, diff is my next stop and probably halfshafts at same time. That would cover ring, pinion, u-joints and splines. Can't see any obvious alignment issue in rear. Noise did change in tone after bearings in, but still there. I can also get it quiet between load and no load.

Also what did you use for video and sound, where were mic(s)? Good vid w/o wind noise yet getting engine. Windows up or down?

froggy47

When I suggested an alignment check, the point was not that an alignment issue causes a noise. The point is that if you find something out of alignment after an off, it could help you find a bent part.

After listening to the vid it sounds like something I have on my 2004 c5z. After the headers and before the cat converters the pipe on MY c5z is of double wall construction (think of it as insulation to keep the inner pipe hot and get the cat hotter faster). It has sort of ripples on the outside pipe.

My inner/outer pipe touch each other at certain rpm and causes a rattley/vibration/resonance. If yours is stock, get under the car with a rubber/plastic mallet and bang on that section of the pipe and see if it makes a noise.

I have "pinched" the pipe with a big c clamp and it went away for a few months & came back. Or have an exhaust guy cut out the double wall pipe & weld in standard pipe, won't effect the cat.

naschmitz

I have a Shure C606WD mic in the right rear storage cubby. Video was shot with a Vio POV HD that has an external mic input. Windows are down.

nolimits

Thanks all, just test drove with a tech I trust, thought it was under console and might be more like torque tube shaft to trans bearing. Will scope and listen for more clues. Arrg.

naschmitz

Torque tube noises vary with engine RPM.
Diff noises vary with vehicle speed.

nolimits

Agree in general, and did rev in neutral test, no change, goes up with wheel speed. Its not independently direct with engine RPM only, ie neutral. This is a tough one with the noise transfer that can go on. Will find out more hopefully Mon listening to it with a scope running on lift.

meldog21

There must have been something very wrong with your car since that Mustang went blasting by you.

Dog

nolimits

Vid was another poster with differential sounds providing some noise perspective. Probably just providing the stang a view they don't see much of our front ends instead of just a flash by and vette tail views. I have had fun playing with a new full race version Boss locally and the outcome is different than the vid

Although mines out of track commission right now and he's running!

nolimits

Well got the car up on the lift running and scoped it. Sound appears to be coming from rear of the trans, main output shaft/bearing maybe. Looks like a trans swap and new torque tube bearings to cover some other things. Slave and remote bleeder too. More after the swap in a week or two.

nolimits

This took care of it. Trans had the issue.

VTME13

Glad you got it fixed! Sorry that it wasn't as simple as the hub change.

What transmission did you go with?

nolimits

RPM T56 level 5. Definitely shifts better than before, smoother. Due to several things; Royal Purple, new slave/throwout, some of RPMs upgrades too likely.

VTME13

Nice. I'm going to have to rebuild mine before too long.