My 2001 SS has 50K miles on it and the rear end started making this noise. What kind of noise? A repetative clunky sort of sound like scraping rocks together. Not the best description I know but I can tell you that the pulses get faster the faster I go and slower the slower I go. It does it in neutral. It does it with the engine turned off. It does it at all speeds.

I took it to the local garage and they opened up the differential. Said it look good. Refilled it. They did say that the rear wheels were loose and so they replaced the axle bearings and seals. But still the noise remains. They could only suggest I put a completely new differential in. I wanted a second opinion.

So before I take it to the GM dealership I was hoping you guys could arm me so I don't get ripped off.

If I can't figure this out I am going to have to let my beloved go and buy a Mustang while waiting for the 2010 Camaro. I've owned Camaros and Corvettes all my life. The thought of buying a stang is a little un-nerving.

 

Carrier bearings maybe, or pinion bearing.
Does it get louder while turning?

did the shop check the teeth on the pinion and ring gear?

 

I haven't really noticed any difference when turning but I will try that out. The shop already ruled out the brakes. I don't know whether they checked out the teeth on the pinion and ring gear. I will pass that question along with comments to check the carrier bearings and pinion bearings to the next tech that looks at it. Thanks!

 

That sounds alot like a broken tooth on either the ring or pinion gear to me also. Are you sure they really took a good look at the gears?

 

If you take it to the dealer, you pretty well know you are going to pay through the nose.

 

96camaroSS, thanks for your input. I am not sure they took a really good look at the gears. They seemed more interested in the bearings and the manager made some comment about his techs not seeing a diff like mine . He also said that the limited slip diff was to complicated for them to rebuild. I'm just a bolt on kinda guy so these things went a little over my head.

If that is the problem are we talking hundreds or thousands to fix?

shoebox, your not wrong, but I am willing to pay through the bleeding nose if I get to keep my SS.

 

Ok, here's a bit more information. I spent 20 minutes listening to it while driving this morning and at high speed it sounded more like chugging. At low speeds it still sounds kinda of metal or stone scraping. The frequency of the sound would seem to be less than the wheel rotation.

I did some u-turns and if anything the sound seemed to be less pronounced. I'll drive around in circles in an empty parking lot tonight.

Finally I have noticed a low moaning sound coming from the rear when the car is decellerating. I don't know if this is just because I am now actively listening or if this is a new sound.

 

If it is the gears and carrier, dealer should be able to replace all of it (gears, carrier, bearings, crush collar, fluid) for under $1200 (labor included).
I would buy a used 10 bolt or save for a 12 bolt vs putting in $1200 a 10 bolt.
Used working 10 bolts in my area average around $200. I picked up my 01 SS M6 rear end last year for $150 after my $1200 10 bolt broke (I didn't pay $1200, got it in a trade).

 

Thanks

 

The dealership wanted $550 to pull the diff apart and look at it and worse case another $4K to fix it. I took it to a local tranny/diff shop and they said $1200 like Zepher mentioned. They also think its the pinion gear, ring gear or both plus the pinion bearings.

They asked if I wanted to replace it with a positrack differential. I didn't know such a thing existed and some places I read say its just a GM brand name of a limited slip diff?

Is my cars traction control going to determine the kind of diff I get? Is traction control positrack?

Can I lower my diff gear ratio while doing this?

If a tree falls in the forest and no one hears it did it really fall at all?

TIA

 

Positrac is GM's term that is interchangeable with limited slip. It is what all Z28s have as stock (though they changed the type of posi in the later models).

 

So why would they be asking a couple of hundred bucks extra for a posi over a lsd ?

 

Posi IS a lsd- just a brand name GM used- Most likely, your 2001 has a Zexel-Torsen limited slip unit, using gears, not clutches.

Traction control is an electronic device, similar to ABS, that requires 4-channel ABS, to monitor eash individual wheel's rotation. If you don't have traction control, ASR in GM-speak, then you only have 3-channel ABS, and the two differentials are incompatible- one takes wheel rotation off the ring gear (3-channel) and the other takes wheel rotation off each rear wheel (4-channel) Different animal entirely from posi or limited-slip.

That said, you should be able to have your differential completely rebuilt for under a thousand dollars- probably looking at $350 or $400 in labor, plus parts- all new bearings, seals, etc. Yes, this is the ideal time to change your rear end ratio, since the whole rear end will need to be re-set anyway- no increase in time or labor costs-

If you change your rear axle ratio, you will need to reprogram the PCM with the new axle ratio, so your speedo works correctly

 

Did anyone check the U-joints?

 

Ditto. When u-joints go they can make alot of different sounds. Clunk, snap, scrape or squeal.