Diff Noise?

[nascardemon]

I am getting a strange sound out of the rearend when I am going between 40 and 50 mph. It almost sounds like a flat spot on a tire, but I have had the tires checked. To me it seems like it is coming from the rear diff...Any suggestions?

 

[colek]

How many miles? 2WD or 4WD?

 

[BlueZ71]

When I am going about 50-55 mph and let of the gas I get a little whine that I think is coming from the rear. The dealer heard it and they want me to drop it off to look into it a little deeper. Maybe in the next week or two. Is that waht you are getting? Anyone else have this?

 

[nascardemon]

My Avalanche is a Z66 2wd model with 21000 miles on it. It doesn't sound like a whine it sounds like a tire flat spot or a bearing noise. It only started making it within the last 2000 miles or so!!!!!!!!!!

 

[WS6Y2K]

Yes there is a problem with our rearends. Just had mine replaced cause bad bearings. I still have a noise not as loud but not like when I first bought the Av. Going back to the dealer very soon. Do a search and you will find out that you are not alone

 

[steelheadchaser]

Hernz is right. Get this to your dealer asap. One reason, for documentation if it should become something major, if it isn't already. Another reason being that the dealer could claim that any serious damage was caused by not bringing it in right away for inspection or repair.

 

[marc_w]

Is the thumping / tire noise the issue - or the whining?

I've had the whining since day one...

 

[pogo]

Deffinately get this checked out. I had my whole axle assembly replaced at 2000 miles due to a howl between 45-50mph. My dealer said they were haveing some problems with the machineing of the diff. case causing missalignment of bearings/gears which caused noises and premature failure of bearings. They said problem seemed to be on Tahoes, burbans and avs around the same age, my was born on 6/02. LOL!

 

[marc_w]

Dang.

Guess I got two reasons to bring the truck in. The leaning and howling.

 

[WS6Y2K]

Just got my Av back from the dealer again. They had replaced everything inside last time I was there. This time they said I had a bad outer rear axle bearing. They said they had replaced this last time and did not know why it went bad again so quick. It has been less than a month since the rearend was rebuilt. I hope these new bearings hold up better cause I have 34K miles

 

[jetpilot2204]

I thought I was a little paranoid, because I have heard this same whine at 40 to 55 mph when coasting since day one and i have 1200 miles on it and the dealer thinks I am hearing tire noise.

 

[BIGBLKAVIE]

what does the bad bearing noise sound like?

 

[Harry of Canada]

Hello Gents

I am having a problem with my rear end also, but not the same as yours. I will get a clunking sound from the rear end intermitently on take off. I mentioned it to the dealer and they said it was my transfer case and it was a normal sound. I didn't like that answer so I have to go for a drive with one of the technicians next week. Have any of you folks had clunking problems with the differential?? I drive an 03 red naked Z71 4WD.

 

[jscotb]

My Avalanche has 45k on it and the pinion and carrier bearings failed. I took it
to the chevy dealer, big mistake. $1100 to replace the bearings. I
told them to seal it back up I was coming to get it. A local mechanic
quoted a price of $400 for the bearings. Since he is so cheap I am
going to have him install 4.10 gears also. Chevy charged me $247 just to
inspect the rear end. This included 3 quarts of fluid at $26 a quart,
so beware. Get your rear diff. checked before it goes out of
warranty. Still love the Avalance, but have never had a vehicle that lost
bearings period.
Planning on writing to Chevrolet about this. Do not expect any response from them, but have to give my 2 cents worth. If it is a housing problem and I lose another set of bearing I will file a civil suit.

 

[wfbarto]

Hey jscotb,

I see that you have a Z66 which has the Eaton rear locking diff in it. Did you have any of the whining noise prior to failure of the ring and pinion as has been noted on some of the other threads on this forum? Reason I ask is I have an '04 Z66 that has a whining noise when I let off the accelerator between 40 and 50 MPH. They already replaced the ring and pinion and the driveshaft which did little to nothing to fix the problem but they say the noise is normal and there is nothing else they can do. Someone else had the same problem and the replaced the whole rear end - hub to hub and it eliminated the problem. He said that dealer told him that there were machining and clearance problems with some of the Eaton rear ends. Just wondering if you had the whining noise prior to failure and if anyone else has heard of machining and clearance problems on these rear diffs?

 

[jscotb]

I had some noise, but I thought it was tire noise. It was very subtle. The mechanic that fixed mine said the bearings were diffective. They hadn't frozen up, but had broken off in chunks. Chevrolet should be doing something about this with all the problems that are surfaceing. I hope you have good luck with yours.

 

[wfbarto]

I thought mine was tire noise also but it is not. It is subtle but noticeable when letting off on the accelerator between 40 and 50 MPH. I will pursue this one more step with Chevy to see if I can get some satisfaction!

 

[Jogyver]

I had the same problem.on my 02 Z66. The noise was a loud grone . so the first time the dealer replaced the bearings, and some other worn parts. Two days later I was back with noise. We ( my kids and I) took the service supervisor for a ride .He ( being a 60 +yr old man, hard of hearing) could hear anything. My kids and I were able to hear the noise. When we got back to the dealership I ask if someone else would go for a ride. The answer was no. I then I asked that since the pinion bearing was worn why was the ring and pinion gear replace. The service guy told me the gears didn't look worn. He aslo stated that there is no wasy to measure the wear on the teeth. That was very questionable. So I insisted that the R/P gears be replaced . They did finally. This was all completed under the factory warranty. Well the problem was gone for awhile. 6000 miles later it's back . Now what especially when the warranty is expired. The noise starts under load at 30 - 45mph then quiets the reappears 60-75mph. There also is a vibration associated with the noise. This really sucks! The big question . Do I take it back to the dealer? Or fix it myself? I will be writting a letter to EATON explaining the issue. I love the truck .. Hate certain engineering aspect of it. Does anyone know if the Cadillac Escalade has the same rear end issues?
Later

 

[jscotb]

I just talked with a Chevy rep about my differintal problems. Since I had it repaired at an outside shop not a dealership, they will not do anything. I had it repaired at an outside shop because the dealer wanted $1100 to fix the bearings and the outside shop charged $400.
I was out of warranty and the dealer wouldn't cover it. Ouzts Chevrolet.

 

[BIGBLKAVIE]

should of went to aamco beep beep

 

[JAWS25]

Any body else getting a bad vibration to go along with your noise? I was pulling a trailer the other day and whoa!!!! I had felt the vibration before, but not under load. I have 35K on my AVY and had the bearings and seals replaced at 27K. I took it back to local dealer after pulling the trailer and they said "vibration is within factory specs". Now, since when does GM set specs for vibrations

 

[sparza7]

Ok, Just had the av in for transmission service, they called and said the tech went out for a test drive and heard a "growl" coming from the front end. Dealer says I have a front differential going bad. I purchased the Av used with 44k miles so I made sure to buy an extended warranty. Now the dealer says he is 80% sure it will be covered by the ex. warranty and quoted me at $1100 for the repair. I can barely notice the sound but it does sound like tire noise from the front and a little whine when I let up on the gas at 40-50 mph. Am I pretty much at the mercy of the warranty co. If they don't cover it am I safe going to a independant shop? What are some suggestions??

 

[PROTECH]

We have an 02 Z71 with 67,000 miles have heard noise since 30,000 miles told it was the tires ,front end all the rest of th bull you heard. I finally took it for a drive today and busted the rear end lemped home in 4 WD. lucky only 1 mile from home.before we make repairs I have contacted GM for advice and also looking fo what you out there have done when the rear end fails. Please let gm know via phone and email at gm.com power train division. If you have replaced rear end please let me know where you got new rear end.

 

[PROTECH]

Up date on rear end. carrier bearing spun in housing there noting left. $3000.00 fix. if your under warrenty. Call your 1-800 # in warrenty book and BBBBBBBBBB. If you dont youll be like me. I took there word for it, that its ok just tire noise, just the way fwd's sound.