2014 Sierra humming noise

fishermen71 · February 24, 2015

I have a 2015 4x4 5.3 Z71 dbl cab with 2500 miles on it now and it's been doing this since day one. Hope GM gets to the bottom of this soon.

majicgoats · March 4, 2015

For those that have been following my issue/experience: I was told at my service appointment which was one week ago today to contact them back in one week to see if they have figured out what they will be doing to repair my truck. I contacted the dealer today. I was informed that the dealer service rep. was up a day or two ago and they discussed my trucks issue. Dealer informed that the service rep. is going to do some "looking into it" and will be getting back to the dealer in a couple days for a suggested next step. So far I feel like the dealer is dotting their "I's" and crossing their "T's" before coming informing me of the plan for repair. I will attempt to be as patient as I can why the dealer comes up with the correct "plan of action".

Update: Long story short, no new news to provide. I have contacted the dealer on a couple more occasions and the dealer is telling me that their "service representative" is looking into the issue and is going to be discussing this issue with "technical assistance" within GM to decide a fix/resolution. I am sure that somebody within GM knows exactly what the issue is and if they don't I would be happy to provide GM my truck for a disection-repair to figure this issue out so that everybody and every dealer knows what to do to get rid of this problem!

kylek · March 6, 2015

Just bought a 2015 Silverado 4WD Z71 and have the same problem. Has 60 miles on it. I've told the dealer and am going to bring it back there today.

Frustrating.

Does anyone have any updates on GM having a fix?

kgweststar · March 7, 2015

Kylek....I had my dealer replace my front differential. 2014 sierra crew cab slt. With help from a factory rep. Noise is gone after replacement.

kylek · March 8, 2015

kgweststar - would you mind letting me know the dealer and their contact info, so I can ask my dealer (Findlay Chevy in Vegas) to call them?

I can give you my cell # or maybe there's a way to direct message thru this forum?

captainbrent · March 8, 2015

I just posted the other day in the HD forum, I have a 2015 3500 HD Duramax doing the exact same humming. Very interested in any new information. I know the only way I will get any resolution to this, will come from info on the forums. My local dealers are incompetent.

2015i GMC 3500hd cc4x4 Duramax

Moxie326 · March 11, 2015

I have a 2014 all terrain that had a humming sound when driving slow after 80 mph it became a shaking issue , dealerships replaced the rear end . Still didn't resolve vibration issues .

Moxie326 · March 19, 2015

2014 gmc all terrain package with humming sounds at slow speeds it's the rear end,!!!! I was passing a car at 80 mph on turnpike had very bad vibration, GM has problems with the ring and pinions ,After the complete rear end was replaced then I start having a very bad vibration in the steering wheel ,Had vibration test done they found the ring and pinion was bad in the new rear end still had vibration after that dealer and GM were no help to fix vibration issues in the steering wheel I had to trade this truck for problems free truck I lost $ 9.000 because of GMC truck sorry for the bad news hopefully your dealer helps you take care of your problems.

Oli4 · March 19, 2015

I have 45000km right now and the noise is gradually becoming worse.

While driving the other day I noticed this. I've never noticed the pitch of the noise change before. At slow speeds 95kmh the noise is low pitched. At 105 it's a 'singing noise'. And at 115 it's more of a whine.

Got me thinking. What turns that slowly in the drivetrain. I indeed came to the same answer as the previous person. Ring and pinion.

I go in for service today. Going to give them an update.

Can somebody from gm acknowledge on here that trucks with 4x4 and 3.73 gears have an issue? I believe that is the consensus right?

Moxie326 · March 19, 2015

I had 3.42 gears in my 2014 gmc after rear end was replaced I had a very bad vibration in the steering wheel, Watch out for vibration issue in steering wheel if they replace ring and pinion .

Oli4 · March 19, 2015

UPDATE

The service tech at Hildebrandt Motors in Olds, AB was fantastic this morning. Super helpful and concerned.

They wrote down my observations in my file again (after they read the notes from the first service back to me). And they requested if the service foreman could have the truck for a day to try to diagnose the issue. It seems like they are willing to help and to rectify the issue. Last time they contacted a GM tech and he said it was a 'normal operating' noise. But they are starting to doubt that. Fingers crossed.

Oh and I also had a leaking radiator (never found a puddle in my garage though). But it's covered under warranty so they can replace it. ;)

I now drive a 2014 Impala V6. It feels weird driving a car again. I'll keep you posted what the verdict is.

Oli4 · March 20, 2015

UPDATE 2

Service foreman replicated the problem numerous times this morning and is now waiting to hear back from the GM technical advisor to see if there's any previous cases. SO the case # that was noted in this tread earlier on SHOULD pop up. FIngers crossed on that. They are keeping the truck and are adding chassis ears to the mix to try and diagnose the issue. But his suspicious is front driveshaft is not fully disengaging from the transfercase or drifeshaft is rotating freely because of something in front diff. Or something like that.

Oli4 · March 20, 2015

Hmmmmmm
Drive shaft phasing.... Check this.

jcchevy · March 21, 2015

UPDATE 2

Service foreman replicated the problem numerous times this morning and is now waiting to hear back from the GM technical advisor to see if there's any previous cases. SO the case # that was noted in this tread earlier on SHOULD pop up. FIngers crossed on that. They are keeping the truck and are adding chassis ears to the mix to try and diagnose the issue. But his suspicious is front driveshaft is not fully disengaging from the transfercase or drifeshaft is rotating freely because of something in front diff. Or something like that.

Good luck Oil4, I know you been dealing with this even before I did, unfortunately there is no GM case or bulletin out there for a "defective front differential". If they use chassis ears properly they should be able to pin point the noise/hum is coming from front diff, thus replacement of the front diff is the resolution. Its just hard for them to swallow replacing a $1500 part while its not technically "broken".

Oli4 · March 21, 2015

Bear with me gm-guy.

What if:

The front driveshaft u joint phase is slightly off. There's play in it. Essentially that play is wearing out the planet gear in the diff and that is creating that hum. The hum is when the planet gear teeth 'grind' or bind because driveshaft slows down (see vid) but diff wants to keep constant speed because of the wheels turning obviously. But when 4x4 gets activated. The u joints get loaded up and angles and phase line up to proper spec.

So. Changing the diff will not change anything. It's the phase of the joints that needs to change.

Bear with me gm-guy.

What if:

The front driveshaft u joint phase is slightly off. There's play in it. Essentially that play is wearing out the planet gear in the diff and that is creating that hum. The hum is when the planet gear teeth 'grind' or bind because driveshaft slows down (see vid) but diff wants to keep constant speed because of the wheels turning obviously. But when 4x4 gets activated. The u joints get loaded up and angles and phase line up to proper spec.

So. Changing the diff will not change anything. It's the phase of the joints that needs to change.