Rear End Metallic Clunk - Dealer Story

[DeePa]

All,

 

I started to notice a metallic/hollow clunk noise when backing up or moving over speedbumps, etc.

 

I took it to the dealer where it could be replicated by shaking the ass end by pushing above either rear wheels.

 

They spec'd out the rear end, and the backlash was fine. GM Tech told them to replace the passenger side axle bearings, both the inner ones near the pumpkin and the outer ones near the brakes.

 

If this does not work, they are instructed to replace the entire rear axle assembly.

 

My truck does have a slight vibration at 78mph, which RF balancing all4 tires helped, and the truck passed under spec on the picoscope.

 

Has anyone else gone through this? All of the rear end gears are fine, just there is side to side play somewhere in there. There were not any metal shavings anywhere, and everything else looked okay. It's being worked on now, and we will see if the bearings fix the issue.

 

On another note, the truck has been there since 12/10. They took their sweet time for sure, and kinda gave me the run around a bit. To make matters worse, they hit another car with my truck, but the damage was minimal and they fixed it, without telling me it happened until it was fixed. This lead me to the dealer to make sure they know that it was BS, and they agreed to fix another paint chip (from me) on the other side of the front bumper...that plastic piece which fills the gap between the grill and the bumper. I did not go there to get something for nothing, but I was not happy with the way it was handled, and I would have them fix the other paint issue at the same time at my cost.

 

Any thoughts? I miss my truck. I'm in a 2015 Tahoe rental, and it's eh. Smells like ass from a previous smoker, no real vibrations, but it gave me a headache from the cabin pressure until I got used to it, which could have been caused by the ass smell.

 

Thanks and merry Christmas all.

Mike

[GMC-AT]

Seems to be a common problem ... there is a real long post about the creaking and clunking ,etc. 7 trips to the dealer for me on my old 2014. They replaced shocks, one at a time. Then leaf springs..one at a time. Seemed to fixed for a while... but sounds came back. For me it was more a hollow creaking sound ... slow speed, especially if the truck was in reverse on an uneven surface.

 

Finally got tired of it and dumped the POS for a 2016. I wanted some of the new things and 6.2 anyway. So far .. the new truck is ok... I just hope it stays that way.

[DeePa]

Did they ever replace anything in the rear end?

[GMC-AT]

just the springs, etc...but it came back with the new springs. It is the springs (and hangers) that is likely causing the noise for most people

[joshc64311]

dealer told me that's normal, and when shaking the rear end you should hear a noise. but these are the same people that keep balancing the rear tires for a vibration only under acceleration. some time I think my 6 year old knows more, every time i go to the dealer they cant repclicate or its normal, cause when hitting a speed bump there should be a hollow metal sound.

[DeePa]

Still don't have my truck.

 

Haven't heard anything in over a week. Left messages, etc...no return calls. I know it's Christmas/New year's but just call me back.

 

I'll keep you all posted. I miss my truck.

[FL335i]

^DeePa. When you say you can replicate the noise by pushing above the rear tires, I'm assuming you mean basically shaking the rear of the truck side to side when it's parked. correct? 1st thing I would check is the torque on the bolts that hold the axle and wheel bearing assembly to the axle tube. And then use a Dial indicator to check for in/out play on the wheel mating surface and compare that to the GM spec. Also check the torque on the U-bolts for the leaf springs. And check the Leaf spring to the frame bolts. You might be hearing the frame hitting the leaf. Misery loves company. I dropped my truck off Tues. Still not back, hopefully Monday. So 6 calendar days to fix some oil leaks. As long as they do the job right I won't complain.

[06-1500HD]

I've been back to the dealership 3 times for this same issue. It really does it whenever I'm backing up with the wheels turned over 1/2 way to full lock. Second time they replaced the axle shafts/seals. They told me that took care of it but by the time I got home the noise was still there. This last time the dealership told me that GM is aware of the issue but they do not have a fix. They said they have several other trucks sitting in their shop with the same issue.

 

Its pretty embarrassing pulling into any parking lot b/c its loud enough that anyone nearby can hear it and will look over. I love GM trucks but this one is beginning to test my resolve.

[DeePa]

So they said they fixed mine, I'll find out more info tomorrow when i pick it up.

 

They replaced axle bearings, no fix, replaced whole rear axle, no fix. Replaced leaf springs and it's fixed supposedly.

 

I'll let you all know the details tomorrow.

[GMC-AT]

why those idiots didn't replace your leaf springs first and foremost is beyond me........

[DeePa]

So...Here's what we got.

 

There was excessive play in the right rear axle, replaced the axle and bearings on that side, still not in spec.

 

Replaced whole axle assembly, fixed the excessive play, but clunking noise still present.

 

Replaced both leaf springs, noise fixed.

 

So it turns out I had two different problems when I went in. The rear springs bushings were shot, and there was an axle issue. I just read on here that trucks were strapped down wrong on the train from mexico...mine might have been one of the trucks.

As far as vibrations, it is no longer present. The RF balanced the tires, and I have the printout from the picoscope but I do not know how to read it.

Thanks all.

Mike