2014 Sierra humming noise

jcchevy · October 8, 2014

Curious if you guys (C6 Doberman, Oli4, RM4665, UCR, or gSwift) have any new updates on this. Oil4, you described it perfect previously and when i put it in 4x4 auto, it disappears as well and when i go back to 2x4, gradually comes back.

Like C6 Doberman, i originally thought my 6" lift 35" tires was part of the issue and the dealer & dealer accessories have looked at the issue and contribute it to "normal road tire/differential noise".

The thing is this didn't start until the 4000 mile mark, and i had the lift and bigger tires put on around 3000 miles and the truck was quiet/smooth as silk.

So something "broke down" around the 4000 mile mark causing this annoying "RUMBLE STRIP VIBRATION" feeling, starts hardly noticeable around 58 and continues to get louder (predominantly around 65) and goes away completely at 72mph or faster.

By the way, i since changed out the aggressive 35" tires with much tamer Open country all terrains, which didn't change the noise one bit, and can actually hear it more now because the new tires are so quiet on the road compared to previous ones.

I have posted this info before on the "novel vibration" thread going on, but most of that is completely different than what I (we) are experiencing. I do believe this issue would have come about if i left the truck stock as well , after seeing so many other posts with stock vehicles experiencing and being able to describe it.

I honestly am waiting for something to break and wish it would do it soon, or hoping they find some common issue and i can print out a technical bulletin to give to the service dept for proof of a fix.

UPDATE !!THIS HAS BEEN RESOLVED!!

It was a bad front differential/axle .(front axle replacement pn: 23186399)

They replaced the front axle entirely. The old one had gray fluids in it and was damaged apparently internally.

Trucks rides as smooth as glass again(thats with 35" tires and 8" fabtech lift). Its awesome.

For those that may have this same issue, have your dealer change the diff oil. The original was super dark and dirty. They also used chassis ears to pin point it to the front diff and opened up a TAC case which suggested to check diff/replace.

So good luck to the rest of yous with the issue. This topic, as mr wonderfull off of shark tank would say, is dead to me ..thankfully

kgweststar · November 3, 2014

I have a hum_______hum_______hum_____ as well between 56-58 and 68-70 mph. No matter if in cruise or neutral. Driver's side front end. Only in 2wd, goes away in 4th or Auto immediately when I switch it over. Gradually comes back fast and slows to normal pace. A little louder in cold weather. Had it since day one. Dealer has confirmed noise. Tells me no fix. It'seems like a rubbing low pitch hum that I can hear over the radio.

4wd not 4th.

jcchevy · November 3, 2014

sorry to hear that @kgweststar, ask (request to talk to service manager if needed) your service dealer to remove the front cvjoints /axles /front drive shaft and take it for a ride with the technician. Once you both confirm the noise is no longer occurring, replace the front differential.

IF, and this is a big if, it still makes the noise after they removed the parts mentioned above, it is NOT the front differential, not the front drive shafter,nor bad axles/cv joints.

But your description sounds exactly the same, that dang hum can overcome the radio and gets in between your mind and trying to enjoy the actual drive of a very expensive piece of machinery, not to mention wonder when the part will fail/cause serious accident.

Some follow up questions for others that will eventually come to this thread.

1) on longer trips,(verify transmission reachs optimum temp 195/200) does it go away. sometimes it takes 35-45 mintues of driving in 70 degree weather for my transmission to get to that temp, just FYI

2) is your truck stock? ( no lift/no bigger tires etc..)

Post back the outcome/good or bad and good luck.

kgweststar · November 4, 2014

I can safely drive at high speeds without those components? Sorry, not too savvi. I bet they'll try to charge me for labor. If so I'll do it just to get that much closer.

It is completely stock

20' wheels

kgweststar · November 4, 2014

It's rear wheel drive. Duh. Forget I asked that dumb question. Wasn't thinking. I'll keep ya posted.

kgweststar · November 4, 2014

Ya, my dealer doesn't want to touch it until GM gives them a bulletin for a fix. Which will be never in my opinion...thanks for your advice but it looks like trade time. What a shame. Rediculous.

kgweststar · November 4, 2014

Maybe you could help me out with another one too...getting a driver's side rattle noise invoked by wind between 30-50 mph. Something is loose knocking around or hitting against the outer panels. Started a couple months ago. Hardware seems to be tight.

Oli4 · November 5, 2014

I wonder when GM is actually going to acknowledge that this IS an issue...

kgweststar · November 5, 2014

Who knows

kgweststar · November 13, 2014

Where are the dealresins located for the ones on here that have gotten their dif replaced or rebuilt? I've found 2 guys now in the gm forums that this replacement worked for them. If I knew the dealer I could call them and have them tell my dealer and give them a bulletin number or something. I'm getting desperate at this point.

Dealerships

kgweststar · December 9, 2014

Gm guy? Would you mind if I contacted the dealer where you got yours done to see if the could give me a lead on what to tell mine?

redwngr · December 12, 2014

Ya, my dealer doesn't want to touch it until GM gives them a bulletin for a fix. Which will be never in my opinion...thanks for your advice but it looks like trade time. What a shame. Rediculous.

Not every problem gets a bulletin.

If the dealer can't fix it on their own, gm has a system to help dealer diagnose and correct. (as GM-GUY out lined in his explanation).

I've seen the system in action (not on this truck). It works, but you've got to give it time to work.

kgweststar · December 13, 2014

Why do other gmc dealers tell me to go to selling dealer when I thought I could go to any gmc dealer? The dealer I prefer to do the work is closer to home and more familiar. Yet they seem to be shy to work on my issue. Warranty should be the same at any gmc dealer, ya? I'll be patient a little longer. Been fighting it for 14 months so far...

ShotgunZ71 · December 13, 2014

Why do other gmc dealers tell me to go to selling dealer when I thought I could go to any gmc dealer? The dealer I prefer to do the work is closer to home and more familiar. Yet they seem to be shy to work on my issue. Warranty should be the same at any gmc dealer, ya? I'll be patient a little longer. Been fighting it for 14 months so far...

Seems very familiar to me. I had the same thing happen when I was questioning my LED rings around the radio knobs. My local dealer kept giving the run around and making excuses after initially saying they'd help. I contacted my selling dealer and they took care of everything for me. Now I understand why many people in the area don't buy at the local dealer, aside from the higher prices they have compared to other GM dealers.

kgweststar · December 13, 2014

Shotgunz71....if you don't mind me asking, what is the led around the knows issue? The red light around my hvac controls are blacked out in spots. Not a full border.