Started happening only since it's been cold. I notice it in reverse and 1st gear from a stop. 30k miles and 3:55 non LS. I'm under warranty, just wondering what would cause this.

I have every issue that possible!

 

sounds like universal joints are gone. you can soak them in oil and see if it stops, but it only a temp fix.

 

Thanks, sounds like that's the issue. I'll have my dealer fix it. I have 6k miles left on my bumper to bumper warranty. It's also covered under powertrain until 60k which is good to know.

 

Haven't had a chance to bring the truck to the dealer. Also, today I noticed a vibrating/buzzing sound at the rear of the truck when it was idling. I figure this sound has to be related to the groan I hear when backing up. I think the cab muffles it a bit and makes it sound more like a groan when inside. I could hear it best when I put my ear close to the license plate. It's not the spare or the tailgate. It's coming from somewhere underneath. Anyone have any ideas?

I plan on taking it to the dealer next week.