ring & Pinion, and rear axle bearings

[00 Ragtop Z]

Need your help. I have heard a wheel rotational type sound (not a grinding or whinning sound, more like whir, whirl) from teh rear end for the past couple months (I posted about this once before). Most often heard about 30-50MPH and when decellerating. Definitely from the rear end, and not associated with the brakes--I had them checked out and they were fine.

Dealer says, ring, pinion and rear bearigns all need replacing (60,000 miles and no hard driving or racing) and the cost will be $1300 parts and $500 labor. He said there were unusual wear patterns on the ring/pinion and some metal shavings. (In one of my previous posts, someone suggested I would know it was wheel bearings because it would sound worse on turning--not the case in my situation)

Now, to me this sounds like a rip-off extraordinair!! Any suggesitons, ideas, or comments (other than "yeah, dealers suck?")??

In normal driving (stop and go, and highway--no racing at all) what are the failure potentials if I do nothing for now IF there really is a problem?

Need some solid help on this one.

[Joe 1320]

First bit of advice is get the heck away from a dealer. Their solution to every problem is to replace every componant. It costs roughly $275 for a gear and installation package that includes all bearings to rebuild the rear end except for the actual posi. There is no way in heck I would charge someone $1000 to rebuild a rear. That is insane!

[N20LT4Bird]

I hate it when I hear stories like this. It makes all technicians look like morons.

Let me translate the dealer's lingo:

"We dont know what is wrong (because we are unskilled) and we need to charge you a lot of money to shotgun the problem and make sure we fix."

Like Joe said, get away from the dealer. Take it to a driveline specialist. They should be able to narrow it down to the actual bad bearing and fix the real problem, not just throw parts at it. Even if all of those parts needed to be replaced (they probably dont) the cost should be about half of that.

Chances are you could drive it the way it is until the noise gets a bit louder, and then fix it. Bearings usually make a lot of noise before they go all together.

[Joe 1320]

My bet would be pinion bearing..... it will get louder before it exits totally.

[00 Ragtop Z]

Probably a dumb question, but exactly WHAT will happen when it 'exits', Joe???? I have had a wheel bearing problem or two in my 36 eyars of driving and know what they sound like (not pretty) but what will the failure be if it is the pinion and what could I expect?

I did get an appointment with a driveline shop here to check it out tuesday--his initial thot was it's likely a bearing.

Any additional comments are appreciated.

[Joe 1320]

As the bearing clearance increases, the rollers do not make square contact and they start to chafe. Eventually the bearings become loose enough that small chunks end up getting torn from the bearing surface and they become pitted. In reality, the noise will increase to the point that you could hardly stand to drive the car before the bearing totally takes a trip unless you go out of your way to abuse it. When the bearing clearance gets to the point where it hardly makes any square contact, the pinion and ring gear will start to wear very rapidly and you'll know it by the sound of the rumble.