Rear end clunking noise

Jimmy W · November 5, 2014

Mine has been clunking and really is bad!!I have 7000 miles on it and it is kept in garage.

Nofastcar · November 6, 2014

They called me yesterday and said it was a faulty "electronic brake module" and they replaced it. They said they could not reproduce the metallic clanking or the vibration.

When I got to the dealer to pick it up it was after hours so I dropped the rental truck gets in the mail slot and got in my truck to leave. I immediately noticed that the brake pedal was extremely soft and wouldn't build up pressure. Not to mention sticky steering wheel and grease on the carpet. So I had to take a couple hours of sick leave this morning to take the truck back. They called an hour ago and said there is absolutely nothing wrong with my brakes and all the trucks on the lot have the same soft pedal. It will be tomorrow morning before I can pick it up (again).

At this point I don't know what to do. The pedal had a good firm feel when I dropped it off now it has almost no pressure but the dealer insists its right.

johnrunner89 · November 6, 2014

I thought the soft pedal was normal. My brake is very soft, sometimes making me wonder if it should be that soft.

GMCustomerService · November 6, 2014

Mine has been clunking and really is bad!!I have 7000 miles on it and it is kept in garage.

Jimmy W,

We're sorry to learn you're experiencing clunking issues with your vehicle. Have you had your vehicle into the dealership? We'd like to discuss this further with you. If you are interested, please send me a private message here on the site with your full contact information, VIN, mileage and dealership name.

Thank you,

Andraya

GM Customer Care

Nofastcar · November 7, 2014

My pedal had a good solid feel before the dealer replaced the EBCM. They looked at it again and said the pedal was normal and was the same as others on the lot. Again I can't stress enough that my pedal was way softer after the dealer replaced the EBCM. After doing some research on the web I found out that the module can trap air in it and needs to be bled with a special scan tool or get the ABS to activate.

So....it's raining here tonight so I went out and slammed the brakes about a dozen time to activate the ABS and presto. Pedal is noticeably firmer. Call BS if you want but that's my story.

As far as the clanking, it very sporadic and my guess is the slip yoke. The vibration is also sporadic but i had a 2015 Tahoe as a rental and I noticed the same vibration when it went into V4 mode and I had a light load but not quit enough to go back to 8 cylinders.

02suburbanZ71 · November 7, 2014

My pedal had a good solid feel before the dealer replaced the EBCM. They looked at it again and said the pedal was normal and was the same as others on the lot. Again I can't stress enough that my pedal was way softer after the dealer replaced the EBCM. After doing some research on the web I found out that the module can trap air in it and needs to be bled with a special scan tool or get the ABS to activate.

So....it's raining here tonight so I went out and slammed the brakes about a dozen time to activate the ABS and presto. Pedal is noticeably firmer. Call BS if you want but that's my story.

As far as the clanking, it very sporadic and my guess is the slip yoke. The vibration is also sporadic but i had a 2015 Tahoe as a rental and I noticed the same vibration when it went into V4 mode and I had a light load but not quit enough to go back to 8 cylinders.

Sounds like my 02 lol. Bad slip yoke and bad straps on the U joint.

Nofastcar · November 7, 2014

Just to clarify I did bleed the brakes at each wheel also. Pedal is a lot better. Not sure why the stealer insisted it was fine.

td33 · November 9, 2014

This question is for Andraya of GM customer care. Will GM honor my drivetrain warranty after 100,000 miles if I document my issue now with 14000? GM is saying it is normal but we all know something is going to break eventually.

LS 1st Gen · November 10, 2014

I'm having the exact same problem. Most noticeable when applying gas after the truck has been coasting for a second.

The "Clunk" or "Thud" is becoming more and more noticeable and feels like bad u-joints to me.

A trip to the dealer is the last thing I have time for at the moment.

Nofastcar · November 10, 2014

My noise is exactly how LS 1st GEN describes. I'd make time for the trip to the dealer. They'll probably say they can't reproduce it but at least it'll be documented.

sthom2255 · November 12, 2014

I just bought a 2014 sierra 1500 4.3/v6 reg cab/reg bed.

has less than 500 miles on it and ....

I am getting the exact same sound!! I,too, took the mechanic with me to duplicate the noise. it sounds just like a defective u joint!! on acceleration and deceleration. also... when coasting down a hill I get the repeating knocking noise.

they did not tell me it is normall, but, rather kept the truck for 2 days until the gmc tech rep showed up. it has been identified as a faulty baffle in the muffler/exhaust system. a new muffler /exhaust system is on order and being installed next week.

the tech rep. told us there is a bulletin out on this issue for 2014 sierra's.

after I get the new muffler installed..... will let you know the outcome.

>>>although the gmc technical representative identified the noise as a muffler/exhaust issue.... I still think it's connected to the u joint/drive shaft area.

the mechanic told me they had some 2014 sierra's sl's that needed to have the driveshaft/u joints replaced and noise went away.

sthom2255 · November 12, 2014

I just bought a 2014 sierra 1500 4.3/v6 reg cab/reg bed.

has less than 500 miles on it and ....

I am getting the exact same sound!! I,too, took the mechanic with me to duplicate the noise. it sounds just like a defective u joint!! on acceleration and deceleration. also... when coasting down a hill I get the repeating knocking noise.

they did not tell me it is normall, but, rather kept the truck for 2 days until the gmc tech rep showed up. it has been identified as a faulty baffle in the muffler/exhaust system. a new muffler /exhaust system is on order and being installed next week.

the tech rep. told us there is a bulletin out on this issue for 2014 sierra's.

after I get the new muffler installed..... will let you know the outcome.

>>>although the gmc technical representative identified the noise as a muffler/exhaust issue.... I still think it's connected to the u joint/drive shaft area.

the mechanic told me they had some 2014 sierra's sl's that needed to have the driveshaft/u joints replaced and noise went away.

ashmores · November 25, 2014

First time poster - but had to voice my concern with the dreaded clunking sound as well.

I just crossed 5,000 miles on my 2014 Sierra SLT 5.3 V8 and have been having the "clunking" noise happen as well (been going on for a little over a month/month .5 - I thought I was crazy the first couple of weeks hearing the noise), but it is only when accelerating (I'm probably missing it when coming to a stop to be honest) and it does not happen every time I drive. Only sporadically. It sounds like the bed is about to fall off - that's how loud/unruly the clunking sounds.

I took it in to be looked at two weeks ago and the service rep actually heard it when another rep was driving it out of the loading/unloading area of the service area so I know I was not crazy (he told me that we could not readily drive it around since it was raining but I felt that since he heard it - my point was made). Got it back a day later and had not heard anything of it. However, I finally heard the dreaded clunking noise again yesterday afternoon and then again this morning while driving to work.

Very frustrating because they actually told me that it was a problem in the bumper area and had sent it to 'the shop' to get fixed. What? So something else was wrong with the truck or BS excuse?

I've already had a hard enough time with them about getting the rear left seat rattle looked at. First time they could not replicate the noise. Second time they said it was the "loose" jack kit under the seat (when I know good and well it was the seat itself because once you hold it down or sit on it the rattle goes away). I eventually had to take the advice of a thread on this forum (I believe it was this forum) and slam the seat down five times and ending up fixing that problem myself. This was even after reading off responses to the service rep from that very thread about the issue!

Edited November 25, 2014 by ashmores

GMCustomerService · November 25, 2014

Hey ashmores,

We're sorry to hear you're experiencing a similar clunking noise in your Silverado. We'd be happy to contact the dealer on your behalf and look into this further. Feel free to send us a PM with you full contact information, VIN, mileage, and involved dealer if interested. If you're unable to send a PM due to just joining the forum, we can also be reached via email at [email protected].

Sincerely,

Eddie A.

GM Customer Care

bladz1454 · November 25, 2014

First time poster - but had to voice my concern with the dreaded clunking sound as well.

I just crossed 5,000 miles on my 2014 Sierra SLT 5.3 V8 and have been having the "clunking" noise happen as well (been going on for a little over a month/month .5 - I thought I was crazy the first couple of weeks hearing the noise), but it is only when accelerating (I'm probably missing it when coming to a stop to be honest) and it does not happen every time I drive. Only sporadically. It sounds like the bed is about to fall off - that's how loud/unruly the clunking sounds.

I took it in to be looked at two weeks ago and the service rep actually heard it when another rep was driving it out of the loading/unloading area of the service area so I know I was not crazy (he told me that we could not readily drive it around since it was raining but I felt that since he heard it - my point was made). Got it back a day later and had not heard anything of it. However, I finally heard the dreaded clunking noise again yesterday afternoon and then again this morning while driving to work.

Very frustrating because they actually told me that it was a problem in the bumper area and had sent it to 'the shop' to get fixed. What? So something else was wrong with the truck or BS excuse?

I've already had a hard enough time with them about getting the rear left seat rattle looked at. First time they could not replicate the noise. Second time they said it was the "loose" jack kit under the seat (when I know good and well it was the seat itself because once you hold it down or sit on it the rattle goes away). I eventually had to take the advice of a thread on this forum (I believe it was this forum) and slam the seat down five times and ending up fixing that problem myself. This was even after reading off responses to the service rep from that very thread about the issue!

I've had the 'clunk' since day one, i've been to two different dealers and both of them heard the noise. one said it's normal and the other one literally blamed it on my trailer hitch haha. i took the hitch off and the sound was still there and the mechanic wouldn't change his diagnosis, said it was the trailer hitch (which was no longer even attached to the truck). Needless to say, that dealership is a bunch of idiots and i told the service manager that.

i hope someone figures out the 'clunk' but im hoping that whatever is causing the sound gets so bad that something clearly fails or breaks so that i can just rub it in both the dealers faces/have it replaced.