2015 - differential gear whine at hwy speeds

[darkfox1]

So, I'm reporting this as an issue, I didn't see much when I searched for it but wanted to bring it up.

 

I have been the owner of a 2015 silverado crew cab LT 2wd since 2/29. I've only been able to drive my truck 11 of those 15 days. It's been in the shop for 4 days now and I've had a (very nice) 2016 loaner.

 

The problem started on day 1, the first time I got it up to 70mph on the interstate after warming things up with 10 miles of backroad driving. It started out as what I would call a "broadcast tone" that seemed to be over the radio, it grew louder until it sounded like screaming gears. This was only on the gas or under load (level ground) and would get quieter or weign as speeds fell, and would totally disappear below 69mph. If you've ever heard straight cut gears, they sounded like this, but very very far away and muffled.

 

I called the dealership this morning and they told me that they are re-gearing it at the dealership with a new ring and pinion.

 

I'm not sure what to think here? My brand new truck has service techs inside the diff? I mean I guess all the work they do is warrantied, but I don't feel super confident about that.

 

I was honestly hoping I'd get a whole new diff in this truck.

 

Has anyone else observed this type of issue? And if so, what was the cause/resolution? They said I might get my truck back tomorrow.

 

It's ok, the loaner is nice and comfortable, but I dont like the 8 speed in bumper to bumper traffic, and I can't do any personalization on a truck that isn't mine. I'm also worried that I may be making the first payment soon on a truck that I don't even have in my posession.

[den1845]

Same problem here with my 2016 Sierra 1500 4wd 8spd trans with a 3.42 gear. I hear the whining noise at 35mph up

to 50mph. After the 2nd visit to the dealer they are installing a completed rear diff asm. My truck only has 5,000 miles on it.

[Brianibew]

Mine did exactly what you described, they first checked the rear differential, that wasn't it, then replaced the transfer case. That fixed it. Only made noise when on the gas.

[den1845]

Interesting...Mine does it all the time on the gas or off.

[darkfox1]

Only when on gas here, truck is 2wd, sound is clearly from back of vehicle, dealer said they found what sounded like an obvious problem, but they're replacing the ring/pinion only, which concerns me.

 

 

Is a shop tech qualified to set gears?

[hirdlej]

I purchased a brand new '15 regular cab short box 2wd truck in nov '15. I bought the truck out of state and 30 miles into my trip home I heard exactly what you're describing. At around 68-74 mph there's a distinct gear whine (probably from the backlash being too tight). The whine is only when steady on the pedal, if I let off it shuts right up. Ease into the pedal again and it starts to whine.

 

I'm almost certain these are being set too tight from the factory. Once the gear pattern has been established (in just a few miles), they need to replace the ring and pinion. They can't adjust the whine out once the gears have taken "set".

 

I would rather have someone who knows what they're doing replace the ring and pinion than to have a whole differential removed from my truck. The less bolts/hardware they touch, the better.

 

Usually most big shops will have 1 guy who is their differential man. This is the guy you want to be nice to. Buy him donuts/coffee/pizza, whatever it takes to sweeten him up and make sure he does the job right. A good differential guy who takes his time will do a better job than the factory.

 

I'll be taking my truck out of winter storage in a few weeks and completing the same repair procedure as you. I already have a tech lined up and I'm ready to go. I told all the boys at the shop if they treat my truck right and I don't find any dents or scratches or extra miles on it, they'll get a pizza party on me.

[darkfox1]

I guess I just expected a truck with 37 miles on it not to need buttering up technicians to get it to work properly.

 

The dealership has treated me very well, to be fair, but I can't help but feel I bought a lemon that I will never be able to trust.

[hirdlej]

My last 4 new GM trucks that I have bought have all had 1 major mechanical thing wrong with them. After the issues were fixed, they all ended up being decent trucks. Relax, it's going to be ok. Just remember the differentials are assembled and manufactured by Mexicans in Silao, Mexico. The rest of my truck is fine other than that. I think the Fort Wayne, IN boys did a good job otherwise.

[f8l vnm]

Same noise on my 16 Sierra with 6.2 as well.

Mine does not whine when I take my foot of gas.

Taking it in to dealer soon

[pm26]

Same problem here with my 2016 Sierra 1500 4wd 8spd trans with a 3.42 gear. I hear the whining noise at 35mph up

to 50mph. After the 2nd visit to the dealer they are installing a completed rear diff asm. My truck only has 5,000 miles on it.

Because the original one is missing a few parts?

[pm26]

Both gear backlash and gear contact pattern must be adjusted correctly and the pinion shaft bearing preloaded correctly for the differential to operate as designed. Violating any one of these parameters will cause grief sooner than later.

[darkfox1]

Both gear backlash and gear contact pattern must be adjusted correctly and the pinion shaft bearing preloaded correctly for the differential to operate as designed. Violating any one of these parameters will cause grief sooner than later.

 

This is why I've never so much as touched setting up gears myself. I trust the experts.

 

The dealer I am working with (where I bought the truck) is one of the larger, older dealers in the city, they have their own collision center too, and the tech that rode with me has been with the dealership 37 years.

 

I trust him, but I dont know the guy doing the diff work.

 

It still just baffles me that a dealership even has a "diff guy."

 

But if yall think is ok. I'm gonna give them the benefit of a doubt.

 

I didn't get the truck back today, tomorrow wil make 5 days, almost half as long as I've been able to drive my own truck.. driving theirs.

 

I think that prat bothers me more than anything else. I barely got to use my own vehicle before I had to give it back and drive a loaner.

[hirdlej]

Please let us know what they end up replacing and if it fixes the problem. I think your parts list will consist of a new ring/pinion gear, 1 new crush sleeve, pinion bearing, shims and a pinion seal along with fluid and gasket. That should do the trick.

[darkfox1]

Called for an update about 30 minutes ago. Still not ready. 5 days so far. Mind you I only got to drive MY tuck for 11 days. Now its been 5 in theirs.

[Ridersfan]

I'd rather my shop set up a differential than an assembly line worker. A shop tech knows what to do and why to do it. An assembly line worker building them just spends their 90 seconds on what they've been told to do and have no idea why they are doing it.

 

I've had a brand new truck arrive at my dealership without a drop of differential oil in it... so the factory has their share of whoopsies. It's something that should be caught on PDI. Not saying that's what happened to yours, but... funny it does whine, it's not the norm. I've only seen it once in my time here