2014 Sierra 1500 SLT Whinning Noise

Shafutz · November 10, 2013

Hello All, I just picked up a 2014 sierra slt with max trailering
package. I just pust put my first 50 miles on it and when i am coasting I
hear a loud low pitched whinning almost a hum. When I give the truck
power the sound goes away.This happens from speeds of 30 miles per hour and up.

Voice link is a little glitchy. It will stop working randomly and when I restart the truck it works again.

Other than that the truck is fantastic

njkrause · December 21, 2013

Any updates on the humming noise?

GMC2014 · December 22, 2013

I have a 2014 GMC SLT 2wd, since day one has had a whining sound that comes in at 38 mph to about 65 the sound is coming from the engine or transmission area. I have taken it to the dealer twice and they advise its the tires. I have Good Year Eagle LS2 with basic highway tread and from what I have read about these tires they are very quiet. The sound is continuous regardless if I shift into neutral at these speeds or accelerate or decelerate, it has no affect on the sound. it does sound like the tires but it is not the tires. My friend has the exact same truck with same tires and does not make this noise, it loud and really bothers me. Just wondering if anyone else has this issue.

pm26 · December 22, 2013

If the whining noise occurs only under load, i.e. with gas pedal e depressed, and disappears when coasting, the most likely cause is improper backlash setting in the differential gears. I have seen whining differentials that made noise only under load, some made noise only when coasting. Improper differential ger backlash setting was the culprit in both cases.

james83 · December 23, 2013

I have a 2014 GMC SLT 2wd, since day one has had a whining sound that comes in at 38 mph to about 65 the sound is coming from the engine or transmission area. I have taken it to the dealer twice and they advise its the tires. I have Good Year Eagle LS2 with basic highway tread and from what I have read about these tires they are very quiet. The sound is continuous regardless if I shift into neutral at these speeds or accelerate or decelerate, it has no affect on the sound. it does sound like the tires but it is not the tires. My friend has the exact same truck with same tires and does not make this noise, it loud and really bothers me. Just wondering if anyone else has this issue.

I am experiencing the same thing on my 2014 SLT 4x4. It first becomes audible around 35 mph and gets louder as speed increases. Loud enough to hear over the radio at normal volume. It's not the tires. I have the Wrangler SR-A's and those should be not be making that much noise. It seems to be something with the differential. Maybe the backlash setting as previously mentioned. I'm taking it in over Christmas to have it looked at. The other trucks I test drove did not have the issue and they were pretty similar to mine.

GMC2014 · December 23, 2013

James83- Thank you for the reply. I'm making a long trip over Christmas and I will take it to a dealer there and see if they can be more help than my local dealer. If your dealer comes up with a resolve, please let me know. Many thanks!

james83 · December 30, 2013

Brought it to the dealer after Christmas and they found lumps in the one of the rear bearings. They replaced it and I'm picking it up tomorrow. Will let you know if that fixed the noise. Sounds like this type of noise is almost always attributed to bad wheel bearings (just google around and you'll find tons of information on it). Hopefully that's all it is!

njkrause · January 9, 2014

james83. was your issue solved with this repair?

james83 · January 9, 2014

james83. was your issue solved with this repair?

Yes that was it. Now I have a new noise. Not sure if I just didn't hear it over the other noise or if it truly is new, but I get a much quieter whine around 40 mph only when coasting. As soon as I give it some gas, it goes away. Might be the pinion gear. It's not bad enough to bother me right now. I want to drive the truck for awhile before taking it back in.

thewhitestallion · January 9, 2014

you are going to hear some whining noise (i.e. gear noise) in these trucks. my gmt-900 would whine at certain speeds. the magic speed is 40mph, when you re-build a rear end with a ring and gear and/or carrier and you go 40mph and hear a whine it is because of improper backlash in the ring and pinion. only you know how loud it is, but depending on how loud it is you are prob just hearing gear whine which really cant be solved because all cars whine some just whine more than others. some cars/trucks are too loud to hear gear whine. but since your truck is new it doesnt hurt to take it back to the dealer and see what they say. hope this helps or informs you on some of the whining.

pm26 · January 9, 2014

I had a whining noise in the rear differential of my '95 Nissan 4X4 V6 pickup which I bought new. The differential would only whine under load at speeds over 45 MPH and it started whining after about 3k miles. As soon as I started coasting the whining noise stopped. The differential was replaced under warranty and the new differential was now making the same type noise, but only when coasting! I just ignored it and did not have any problem with it for the next 10 years when I traded the truck in. Thankfully, I do not have this type of whining noise in my Silverado pickup. This noise was definitely caused by improper gear backlash setting (improper shimming of ring and pinion gears).

You can reduce the differential noise by using higher weight gear oil. In fact Nissan came up with a TSB recommending just that. Using 80W140 weight gear oil did quiet the differential some. I would not recommend using such high viscosity gear oil in cold climates though.

GMC2014 · January 25, 2014

Yes that was it. Now I have a new noise. Not sure if I just didn't hear it over the other noise or if it truly is new, but I get a much quieter whine around 40 mph only when coasting. As soon as I give it some gas, it goes away. Might be the pinion gear. It's not bad enough to bother me right now. I want to drive the truck for awhile before taking it back in.

Glad to hear your dealer was able to correct your problem. My dealer is still advising me its the tires as I have previously stated. It is now even louder and If anyone has the same problem please advise me of any information. GMC thus far has been of no help. A possible bearing failure is concerning me for several reasons and not to mention I have to drive around listening to it. I really like my truck with the exception of this noise. Thank you in advance for any input.

klrrdr · January 25, 2014

I had a whining noise the first couple of trips out, then I left her home

pm26 · January 25, 2014

It takes a an experienced mechnic to properly assemble a differential. Since GM moved the production to Mexico and the parts like the differential assembly are made who knows where, it is entirely possible that those assembling these differentials are not doing it properly. Hence the whining noise.

james83 · January 25, 2014

The dealer took a look at the other noise I am having and they say that it is the flapper valve in the muffler and that it is normal. Other trucks I test drove including the loaner I had recently did not make this noise so I don't think its normal, but I also think every truck is going to be different and make different noises here and there. Since its not very loud and I only hear around 40 mph while coasting, I'm not all that concerned about it. The previous whining noise I had most definitely wasn't normal, and most definitely needed to be fixed. If yours is as you describe then I would force the issue with the dealer because its definitely a bad bearing! Have them put different tires on and prove that the noise is not the tires. If they aren't willing to do that then take it to another dealer because that is poor customer service.