James Colvin

Hey Guys I have recently had my rear drive changed with 3:73 posi and all new bearings. I have a minor whine when theres no load, meaning that its the transition point where I'm not on the gas and I'm not slowing down more like when I'm coasting. The guy I had put it in said he shimmed it on the first test drive. Does this mean it could be shimmed some more to completely get rid of the whine? If I leave it alone could damage result?
Thanks

nsnarsk65cutlass

Whine noise from rear gears is a symptom of the gears not being set up properly,(on new installation)backlash,preload,pinion depth, etc.Leaving alone it may or may not cause damage but rest assured it will Not get any better.Nick

rjohnson442

I know it's brand spanking new but is the fluid level full? They definitely get louder with less fluid.

CutlassDad

When the gears are shimmed properly, there should be no need for re-shimming. Since the car has been driven with the gearset not correctly shimmed, they may not ever be truly quiet.

James Colvin

Ya that's a good point I'm taking it back to the shop to be safe.
Thanks

James Colvin

I would think they filled it, I know none has leaked out.

James Colvin

Only have a few hours on it so far, hoping it will be quieter when I have them check it out thanks

CutlassDad

"A few hours on it", as in 100 miles or so?

I would get the checkout done sooner than later.

70cutty

Some gears are louder than other. My car has a minor whine since I put in 3.42 posi some 7 years ago.
Right after break-in I took it to different shop(than the one that install the posi) to get checked out and everything was perfectly fine.

droldsmorland

Either way it sounds like you should disassemble the rear to inspect. Check the contact pattern first before surgery. If the contact patterns off then disassemble adjust shim etc..I've seen a bearing/race get damaged from aggressive installation. So if the contact pattern checks then its likely bearings. Crush sleeves and shims are a bunch cheaper than a new gear set and an exploding rear.
Wish these rears had a 3rd drop-out member....