billscamaros

iTrader: (1)

I've got 275K miles on my '99 Z28 M6, and just started to hear a "whur" sound out of the rear end. I had a new pinion bearing installed at around 210K miles.

So, a couple of questions. The axle code is GU6, I do not have traction control on the car, and it's a "3 channel" rear (does not have ABS sensors at each rear wheel).

My inclination is to take it to a shop and have the axle, carrier and pinion bearings all replaced. What about the Torsion unit? Replaced also, or it should be ok?

I've called several salvage yards to see about buying a lower mile rear end. I can find rears out of 6 cylinder cars all day long, but not anything out of a Z28. Are all "non-traction control" rears the same, regardless of whether they come from a 5.7L car or not. I don't particularly like the idea of finding an used unit with unknown miles and problems.

I drive this car to and from work, 120 mile round trip. So I'm perfectly content with the stock rear end. I'm not interested in upgrading to a stronger rear since I feel as though I've gotten good service out of this one.

Are there vendors on LS1Tech who sell a rebuilt, warranted complete assembly?

Thanks

Bill

FirstYrLS1Z

iTrader: (4)

regular V6 rears were non-posi 3.08. V6 rears had drum brakes for up to and including 1997.
a V6 option package(not common) for 95-97 had posi and could have had 2.73 or 3.23 gears.
a V6 option package(not common) for 98-02 had posi and could have had 3.23 or 3.42 gears.

JOHNNY59

iTrader: (398)

pm sent

Bob@BruteSpeed

iTrader: (16)

275K miles and with an M6 to boot, that is amazing the rear has lived this long! Your cheapest way to go is going to be to find a good low mileage 10 bolt 3 channel rear. They're not as hard to find as it sounds, as many of these cars are built for 500+ rwhp and the stock rears are swapped out for stronger rear ends. Bob

billscamaros

iTrader: (1)

Thanks Johnny - I've responded to your message.

Bob - I can go on and on about this car! It's been my commuter car since 2001, gets 26 mpg consistently and it runs great. I bought it for $19K with only 19K miles on it. I'm a pretty conservative driver, so it doesn't get very much abuse. It's on the third clutch, second fuel pump and still has alot of original parts on it. The muffler finally rusted out this past summer and I replaced it with a Flowmaster cat-back system. I've totally rebuilt the front and rear suspension, and lowered it at the same time. Second power steering rack.

I'd probably go with a newer Gen 5 Camaro or a Corvette if I had the cash flow. But with kids in college, things are a little lean for me. It's definitely a long term car for me.

Thanks.

Bob@BruteSpeed

iTrader: (16)

That is awesome, sounds like a keeper for sure! Bob

nascarnate326

iTrader: (1)

Personally I would find a WELL KNOWN shop that does rear ends and have them completely redo yours.

Make sure the shop is known for good work, previous owner of my car had a shop put 4:10's in and it whined horrible to the point it was unbearable to drive. If it makes any noise at all, take it back and have them fix it.

In my area it was hard to find a good posi ten bolt that wasn't beat to ****, or priced sky high.

I got a 10 bolt out of an auto WS6 with 3:23 gears. Looking back I wish I would have just paid the local shop that does good, pricey work to fix my original rear end and put 3:42's or 3:73's in it. Hope that helps.

billscamaros

iTrader: (1)

To come back and close this thread out .......

I contacted Justice Racing in Frederick, MD to have him take the rear end apart and diagnose the problem. He's a sponsor for the local car club.

I asked him to - no matter what he found - replace all the bearings inside the rear, since I knew that the axle bearings were original to the 276K mile rear. The torsion unit and the gear set turned out to be in fine shape, and we just kept those in place.

The pinion bearing had gone bad once before and I had it replaced quite awhile ago, but apparently the bearing had spit out a couple of rollers and those were still loose in the case. I had pulled one off of the magnet when I was checking the rear out a couple of weeks ago, and Justice pulled one out when they went thru it this past week. The crush sleeve was fairly chewed up from something, which apparently was the cause of the "clunk" as the car moved from a stop.

So, all the bearings and seals replaced, the torsion unit and gears are still good and I should be good for some more miles. I've got a couple hundred miles on it now and everything seems to be good.