Noisy transfer case in 4Hi-2018 2500HD GMC Gas

rtreptow7 · February 8, 2019

So I put my 2018 GMC 2500HD 6.0 in 4 hi for the first time today as it was snowing heavy. The thing was whining and noisy like I’ve never heard before. Worse on deceleration and acceleration and worse above 35 mph. It sounded like it was coming from under the passenger side floor. (transfer case?) I had a 2017 truck too in the exact same model that was no where near this loud. In fact, I could not even hear the difference between being in 4wd or 2wd. A few times I would forget the 2017 was even in 4hi. There is no mistaking it in this 2018. I did some searching on the net and came across a service bulletin about a noisy transfer case in 2015-2018s that they claim is normal. But I don’t understand why the 2017 would be so quiet and this one so noisy? I do have an appointment on Monday at 7am to have it looked at. I'm afraid they are going to tell me it's normal. My uncle as a 2016 2500HD and it too is very quiet in 4hi.

lew-e · February 8, 2019

Took my 16 1500 in last year because of the noises and they drove it around and tore it apart and said everything was fine. Some are just noisier than others. Makes zero sense to me.

rtreptow7 · February 8, 2019

If that's the case, and everything is fine but it's just noisy, I can live with that.

Mike Barber · February 8, 2019

I thought the same thing the first time I used 4H on the road in my 2016 Chev 2500HD 6.0. I asked the dealer shop about it and they said it was normal. It took a while to accept it as normal but I am used to it now and nothing has busted so I guess it is OK.

My Fords, Jeeps and Dodges sure didn't whine like that.

I also have a low speed rotational noise they either say is normal or that they can't hear it. The only time I notice it is in a quiet parking lot or, oddly enough, driving around the local dealer's lot to get to the service department. They can't hear it all the time though. I quit worrying about that one, too.

Other than that, I must say I am very pleased with this truck. I still comment to the GF every so often about how good of a truck we got. It is comfortable, plenty powerful, tows the boat really well, and looks pretty good. It also has a good stereo so I don't have to listen to the drivetrain noises!

avalonandl · February 8, 2019

Straight cut gears, lots of noise.

i82much · February 8, 2019

just pretend it is a rock crusher muncie in your 454 chevelle, aka “melba toast.”

Cowpie · February 9, 2019

My 2015 has been noticeable when in 4hi since day one. I guess noisy is relative. I really just sort of blank it out. I have to actually be listening for it before I actually notice it.

crankman · February 9, 2019

Agree will all, I had same feeling at first but dont even think about it anymore.

Cowpie · February 10, 2019

Yeah, and I am probably on the camp of those who actually use 4x4 frequently. Hardly a week goes by when I am using the pickup that it is not in 4x4 at some point.... year round. 4 years and if there was going to be an issue, it should have showed up by now.

Silverado4x4 · February 10, 2019

On 2/8/2019 at 10:00 AM, rtreptow7 said:

So I put my 2018 GMC 2500HD 6.0 in 4 hi for the first time today as it was snowing heavy. The thing was whining and noisy like I’ve never heard before. Worse on deceleration and acceleration and worse above 35 mph. It sounded like it was coming from under the passenger side floor. (transfer case?) I had a 2017 truck too in the exact same model that was no where near this loud. In fact, I could not even hear the difference between being in 4wd or 2wd. A few times I would forget the 2017 was even in 4hi. There is no mistaking it in this 2018. I did some searching on the net and came across a service bulletin about a noisy transfer case in 2015-2018s that they claim is normal. But I don’t understand why the 2017 would be so quiet and this one so noisy? I do have an appointment on Monday at 7am to have it looked at. I'm afraid they are going to tell me it's normal. My uncle as a 2016 2500HD and it too is very quiet in 4hi.

Check the fluid level in the transfer case, when my 2015 was new the transfer case was noisy also after I checked the fluid level it took almost a quart of fluid, after adding it the whine quieted down about 50%

Big Whiskey · February 11, 2019

My truck makes the same noise too. I was worried about it until I found multiple threads of guys who already had their dealer check it out and claim everything was "normal." My dad's 2017 2500HD 6.0 does it too.

TXGREEK · February 11, 2019

My 16 DMax which was in 4x4 every week never made a sound while in 4hi. I’d call GM and let them know so you can have it checked out.

Sent from above

Cosmic Charlie · February 11, 2019

and my 2004 , 11, & current 15 (all HD 6.0's) were all very quiet in 4WD Hi - go figure

rtreptow7 · February 11, 2019

I just got a call from the dealer and he had 2 different techs drive it and said the noise it makes was normal. They didn't have another truck there to compare it to. I should monitor it and bring it back if it gets louder or changes in any way.