2015 Chevy Silverado LT 5.3L 2WD Bump in rear during acceleration from stop

IIIEXOCETIII · December 2, 2020

Hey guys, new to the forums here. Finally had to reach out after being confused for a while.

Have had a weird issue going on lately with my truck. Or at least just started noticing it.

During acceleration from a stop, either from a typical stop light, or perhaps stop sign, I am getting a pop or bump in the back under the truck. Almost feels as if I have left something in the bed and it slid and hit the tailgate. Or perhaps a spare tire that was loose that swung and hit the bumper. It has been baffling me for a while now. I've tried slow accelerated starts which seem to not be as persistent. Perhaps 25-50% of the time. But if I hit it slightly harder it's more pronounced and happens about 95% of the time. I've tried to see if I feel it in reverse too, but it just doesn't seem to replicate as easily in that fashion. But, I'd go out on a hunch and say that I've felt it a couple times while accelerating backwards into my upward facing driveway.

The truck in question is a 2015 Chevy Silverado LT 2WD 5.3L with 88.5k on the dash. Has never towed anything besides a uhaul trailer for moving years ago. So far this truck has been amazing without any major issues. Fingers Crossed.

Last transmission flush was done about 12k ago. But I really don't think that is the problem as it shifts and moves into reverse and other gears smoothly. Is there anything that would be causing this particular issue? Being that it is a 2WD, I don't have a transfer case I do not believe, where splines could be an issue. Is this something that U-Joints could create? Truck is in stock condition and nothing has been altered or changed.

I appreciate everyone's response in advance, as there are far better folks out here whom will be able to assist in this than I will ever be qualified for.