2017 Sierra Intermittent howl noise when pulling a trailer.

[menthe_dakine]

Hey! I have a 2017 GMC Sierra All Terrain with the 6.2L and 8 speed transmission. Today I decided to go grab my 16 foot enclosed cargo trailer with the quad inside to go and clean everything up. I noticed when I was on the off ramp to come off of the highway I felt a "revolving" vibration. I turned off the radio and could hear a very faint but noticeable howl coming from somewhere, obviously underneath the truck but it's so quiet that you can hear it but not be able to pinpoint where. And this was happening around 70 KPH. The trailer and quad together doesn't weight that much and shouldn't have any impact on the truck at all. I finished up washing everything and went to drop the trailer off. So I decided to try it again. Nothing. Can't hear anything at that speed at all. So I'm wondering, could there be something wrong with the diff on my truck when it's underload? Mind you this was happening while either just coasting or minimal throttle on. Or maybe it could be something with my trailer? I'm not to sure.

[Sierra706]

Hey! I have a 2017 GMC Sierra All Terrain with the 6.2L and 8 speed transmission. Today I decided to go grab my 16 foot enclosed cargo trailer with the quad inside to go and clean everything up. I noticed when I was on the off ramp to come off of the highway I felt a "revolving" vibration. I turned off the radio and could hear a very faint but noticeable howl coming from somewhere, obviously underneath the truck but it's so quiet that you can hear it but not be able to pinpoint where. And this was happening around 70 KPH. The trailer and quad together doesn't weight that much and shouldn't have any impact on the truck at all. I finished up washing everything and went to drop the trailer off. So I decided to try it again. Nothing. Can't hear anything at that speed at all. So I'm wondering, could there be something wrong with the diff on my truck when it's underload? Mind you this was happening while either just coasting or minimal throttle on. Or maybe it could be something with my trailer? I'm not to sure.

Was your afm active and in 4 cylinder mode?

 

 

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[menthe_dakine]

Yes, it sure was.

[Justin101714]

I'd be inclined to say it's howl from the AFM. Rear ends wont howl when coasting.

 

 

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[menthe_dakine]

Do I have to be worried about that? Because I've never heard that noise before. And yeah like.i said before it happened either while coasting or minimal throttle on while the V4 mode was on. And that was only when the trailer was on.

[menthe_dakine]

I'd also like to add to that when I was testing it with the trailer on, once I heard the noise, I put it into neutral and it still made that low howl/hum noise.

[vinemann12]

Have you tried to drive your GMC with trailer attached in "Manual", M-1 to M-7 Mode to eliminate any possible V4 drone type noise ?

 

Cheers---K

[menthe_dakine]

I haven't had a chance to try that but I will next time for sure though! I barely drive with the trailer. Mainly for camping and such but I will watch out for that. If that's all it is, is just the AFM then I'm not too worried. Just don't want something wrong with this beauty! Lol

[NWI Denali]

Good suggestions. My first thought was V4 mode as well.