Rear end noise

[Bulldog]

Bulldog with a question which I think I know the answer. But would like some feed back. Have developed a rear end noise in the 8.8 comes in about 50 miles per. A whine that goes up and down with speed. Pulled cover and inspected rear. ring and opinion teeth look good depth looks good on gears very little fragments on magnet back lash seems good also . Am thinking it may be opinion bearings does any one have any advise ? Thanks.

[eschaider]

There should be no fragments in the oil or on a magnet.

Ed

[rbgray1]

Bulldog,
I just had a colonoscopy this morning so that may be the rear end noise...

Just kidding but I did have the colonoscopy, all good.

Noise is almost always from the pinion bearing or lash of the ring and pinion. Metal or not, I'd look at the lash on the pinion and ring then look to replace the bearing regardless. Not that tough to do once you have the pig apart especially what we do to these cars...Are you running a modifier in your 80W diff lube?

[Bulldog]

Rbgray1 yes to the friction additive royal purple 75/ 90w with additives thanks to all for response . I will keep an eye on it probably will have to do a tear down .