I recently installed a new rear end in my camaro, and had the new gears proffesionally setup. They were silent at first, but I did not do a proper break in, I drove it about five miles easy, let it cool about five minutes, then proceded to do about five quarter mile blasts. After that I could hear a faint whir sound under light throttle. after about a 20 mile drive, I drag raced my buddies car, twice, and then the rear end whir was terribly loud. It is silent in first gear, but then gets louder with more engine load and speed. It is silent on deceleration, until about 20mph, then it comes back, but with a pulsing sound that gets louder and slower as I slow.

I dissasembled the rear, the gear oil looks like metalic grey paint, but I can not see any wear on the ring and pinion, but I am no expert, the backlash still seemed correct, and the pinion nut did not back off, so I wonder if a pinion bearing could have went out? Would that give me these results? Has anybody toasted a ring and pinion from imprper break-in? I have two different rears set up, and never broke them in corectly, this is the first time I have had any problems.Any thing else I should look for?

 

u sure the gears where installed right? if u have a 4.10 gear is a partial non hunting gearset and has to be timed...

 

They were 3.73 gears, and I am 100 percent sure they were installed correctly by a trusted shop.

 

ok well ur side thing said 4.10 so yeah...but 3.73 are hunting gears no timing required...sounds like maybe a bearing...

 

The "metallic gray" lubricant sounds AWFULLY suspicious.
It might sound trivial, but determine what the "reputable" shop
used when they re-assembled it, and what it looked like then.
Assume that the appearance is due to a high content of powdered
metal. IMHO, its more likely that a bearing is grinding itself up.
You didn't indicate whether bearings were replaced during the
re-build. My first reaction would be to start back at the "reputable
shop" to explain the lubricant condition.
Worst case, drain/flush/re-flll, and try again.
If the noise goes away, then repeats, something else
is failing, and contaminating the lubricant.

Good luck