A list of problems, need advise on what to do

[cwest94]

I have a 2000 ZR2 Blazer that just turned 60k miles. I've been having problems with the brakes, rumbling noises, and every once in a while I hear some kind of a banking sound coming from somewhere. Well I just got a call from my mechanic and found out the rear seals are leaking and will also need to get new brakes and rotors put on the back. He also informed me that my right rear bearings are bad, and this is the rumbling noises I keep hearing. He then proceeded to tell me that when he had it up on the left, that when turning the rear wheels a lound banging sound comes from the rear differential. He said that he will not know what this is till he opens up the rear differential and said he never heard something quit like this before.

 

He said the rear differential could just be some of the plates need replaced, this car does have positive traction, at least I think it does. He said that he has opened up rear differentials before and wish he never had because it got to expensive to repair.

 

Does anyone have any suggestions or have had problems like this before, and can offer any advise if its worth fixing or just trading it in on something new? I'm willing to do the seals and brake job and even the bearings, but I'm very scared about the rear differential issue. I'm just wondering if this issue is just normal with the posi traction.

 

Think it's also worth spending money to get the dealer to look it over and see what they say for a second opinion?

 

My mechanic has been working on cars since he could walk, he is a older person who does not cheat or lie to anyone, so I fully trust what he says.

 

Thanks in advance on any info you can give me, I feel like I'm stuck under a bolder right now from hearing this news. It makes me even more sick when I think that I just almost traded it in last month but decided to keep it and just stash my money in the bank for a house instead.

[foxySS]

Yeah, I hear ya- S-10's resale is garbage. I almost sold my S-10 a while back but didn't, and now the transmission needs to be rebuilt here very soon. Not only that, but it has a list of other things that need to be fixed on it too. It sucks when the cost of fixing starts nearing what the vehicle is actually worth.

 

In your case, I would just repair the brakes and bearings and see if that fixes most of the problem.

[hot rod truck]

Hey Chris,

 

Sorry to hear you're having problems at only 60k on the truck.

Outer bearing and seals are not that uncommon of a repair on GM axle.

Rear brakes may need replaced because gear lube got on the rotors and pads or are worn out. Could be both.

The rear cover has to come off to get the axles out anyway. You may want to be there when he pulls the rear cover to see what he finds.

 

I take that you heard only the rumbling noise and not banging or clanging while driving the truck. If you did hear banging or clanging, was it when you turn corners? If so this good be noise from the posi clutches ( if it has that style posi) Normally a fluid change and posi additive will eliminate the problem.

 

I don't think this is what you're looking at but here is, Worse case scenario: Broken ring & pinion, posi carrier, bearings.

Parts from Randy's Ring & Pinion for everything I listed above will run you about $800.00 plus labor to install. A used rearend will probably cost you that much as I've seen them get pretty expensive over the last few years. I would get in touch with Quik for the labor as it sounds like your mechanic probably is not comfortable with rebuilding diffs. That is not a slam at your mechanic, just not everyone rebuilds them, they'll put used or a reman like Jasper in because they're not trained in that area

 

Hope this helps

 

Brian

[cwest94]

After I posted this reply, I thought of something that could be causing the problems with the differential. Last week I was backing out of a parking spot and someone else behind me wasn't looking and started to back right into me. In a last section reaction, I through the car into drive while still in reverse. When I did this, I heard this lound bang coming from the rear differential, and my tires chirped real loud.

 

When I went over to see my mechanic , he put the car back up in the air, if you spin the rear passanger side wheel real hard, it will hit a point where it will stop instantly and you hear a bang from the differential. So now I'm not sure if maybe I damanged something when I put it into drive from reverse and this damaged a clutch or plate in there or not.

 

Other wise, it really isn't normal for the wheel to stop spinning instantly like that, is it?

 

I wonder if I can get everything else fixed and just ignore the rear differential thing and never have any problems. I do a lot of highway driving and my mechanic said he cant tell whats wrong till he opens it up and he said there is no way to tell if something might happen while driving or not, he said it might be fine or that it could lock up.

[hot rod truck]

With your additional explanation, it is possible you sheared a tooth or a couple teeth off the ring or pinion gears. The wheel turns until it encounters the broken teeth getting caught up in between the ring and pinion gears that are still intact. Any debris in the diff will float and move around in the gear oil.

 

If it is the ring and pinion you can probably reuse the posi carrier. That will cut the cost in half for parts, possibly more. Randy's Yukon (their house brand) gear sets are usually around $200.00 plus the bearing/shim kits about $100.00.

 

Hope it all works out

[Fireman31]

When I went over to see my mechanic , he put the car back up in the air, if you spin the rear passanger side wheel real hard, it will hit a point where it will stop instantly and you hear a bang from the differential. So now I'm not sure if maybe I damanged something when I put it into drive from reverse and this damaged a clutch or plate in there or not.

 

Other wise, it really isn't normal for the wheel to stop spinning instantly like that, is it?

 

It sounds like the locker on the rear diff is locking when you hear that bang. One axle has to rotate a certain speed (ie 50-100RPM) in order for the locker to lock up. It stops moving because it is now locked with the other axle and does not have engine power or momentum to keep them both spinning. I could be wrong though,

just my.02.

 

You would know if the carrier bearing is bad...you would hear a humming sound from the rear end that gets worse the faster you drive. With the kind of mileage that is on your ZR2, I highly doubt that the rear end is bad. It might be wise to have it checked and serviced with fresh gear oil while it is in the shop if you are that worried about it. Keep us posted of the outcome.

[cwest94]

Guess I have another question. When my mechanic was spinning the rear passanger side wheel showing me how it would instantly stop and hear that bang, he was only able to reproduce this when spinning the wheel in reverse and not forward. Is it possable that I may only have problems in reverse and could be fine driving it since I'm never really in reverse? Or was this just because the car was on the lift and not in real road driving conditions?

 

And would just draining the rear end and refilling flush things out to allow me to keep driving it without having to worry about things locking up on me?

[hot rod truck]

Sooner or later you will have to address whatever the problem happens to be.

Based on what you have already posted about the outer axle seals/bearings being bad, you will have to remove the cover to remove the axles (C-clip style) so you will be there anyway and can inspect the diff for any other problems and get it fixed before it locks up and leaves you stranded

 

Hope this helps