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Has anyone experienced a whine when operating in 4WD-high. I notice it at all speeds and is only heard when operating in 4WD. 2015 Sierra Denali 2500HD

 

 

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One of the many advantages of the new 2015 MY pick-ups is the cabin is quieter compared to previous model years. For that reason, when the vehicle is in 4WD mode (HI or Low), there may be some noticeable sound from the transfer case.

 

This sound may be described as a whining. This sound can be described as being a very broad band frequency.

 

With the vehicle in 4WD mode, this sound will be present on both acceleration (30-40 mph) and deceleration. The sound will increase when driving on dry pavement in 4WD. It can also be identified since it disappears or reduces considerably in 2WD mode.

 

 

Also, check your tire pressures front to rear. The spec tag on the door has the front usually 10-15psi lower than the rear on the HD trucks.

 

On certain models, such as 3/4 and 1 ton vehicle, tire pressures can vary from front to rear based on the manufacturer’s specifications. As an example the manufacturer’s specifications for tire pressures on a 03 K2500 Suburban are front: 50 PSI, rear: 80 PSI. The difference in tire pressures affects the rolling tire circumference from front to rear which can increase driveline noise while in 4WD which is an operating characteristic. For test purposes, drop the tire pressure in the rear to match the front. If the noise is reduced or eliminated this confirms the difference in tire pressures from front to rear can affect the noise when operated in 4WD. Set the rear tire pressure back to the manufacturer’s specification.

 

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Mine doesn't whine, even when i drag raced going 100 off the speed limiter in 4x4 high for about 10 miles, it was a very snowy night Only whine i ever got was from going 40 mph in 4 low!! That thing was skipping like crazy!

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Mine doesn't whine, even when i drag raced going 100 off the speed limiter in 4x4 high for about 10 miles, it was a very snowy night Only whine i ever got was from going 40 mph in 4 low!! That thing was skipping like crazy!

If you did 40mph and 4low your engine would have thrown it guts up all over the place.

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If you did 40mph and 4low your engine would have thrown it guts up all over the place.

Oh it was. It was on the rev limiter the whole time. We had a terrible blizzard last year and lifted f350 and f250's and 6.6 2500's were all stuck everywhere there was 4 feet of snow we were pushing snow over the hood. The ALT kept dropping volts from the snow coming in and one guy in a lifted f250 said "you cant make it past i just came that way" well we did make it in the stock suburban at the time and it was the easiest part of the trip we had to have it floored the whole time in 4 low otherwise we would have not made it back because the snow was so tall.
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My 2015 2500 is at the dealership right now for the same thing. Snow storm last Wed. and used it for the first time, 3-4" of snow on the road, sounds just like gears not meshing right, truck seems to be laboring a little on the highway. Should be getting the old "everything is normal" talk tomorrow from the dealer. Also has a lag in 2wd when you just roll into the throttle when at speed the engine revs a hundred or so RPM and nothing happens.

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I'm sorry to hear this about your truck, Gun Designer. It's great that you brought this concern to your dealer's attention for service. Feel free to follow up with me when your truck is back in your hands. If further assistance is needed I'm here to help. Please don't hesitate to reach out to me!

 

Kristen A.

GM Customer Care

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Hey Dan,

 

I purchased a 2500 Denali HD with the Duramax 2 weeks ago.

 

The high pitch whine coming from front differential while the 4Hi is engaged is also present on my truck.

 

I'm in Canada and I paid 90 000k for this truck here...To me it looks like a bad design into the angles of the front drive shaft VS the U joints VS the front differential itself.

It's a shame that a truck of this price has those kind of issues.

 

A friend of mine also owns a Sierra 2500HD SLT 2015 with the Duramax and he has the same high pitch whine heard while in 4Hi.



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