2016 Silverado clunking noise when accelerating from full stop

[sac55]

Hi all - I am hoping for some help/advice/thoughts/suspicions. I have a 2016 Crew Cab Z71 5.3 Silverado. I have 20' fuel wheels and 33 inch Toyo Open Country tires. I have a 3' front spacer and Bilstein 5100s. Intermittently, I hear a clunking noise when I accelerate sharply from a full stop, example - foot on brake at a stop light, green light, hit the gas and there is a quick clunk. No loss of power, doesn't sound like anything is grinding. The clunk never exists on a light acceleration and is only intermittent on the sharp acceleration I described. No difficulties when putting the truck into gear. This has been going on a few months and I've done research here on the forums and elsewhere. My first thought was the u-joint, sway bar and even a slip yoke or engine mount problem. I took the car to the suspension place yesterday and they said everything looks good there. This morning, I took the truck to the dealer and they were able to replicate the noise but determined it is not drivetrain related. 

 

Anyways, they likely won't figure it out until tomorrow. I'm trying to stay optimistic but I am also never optimistic when my truck is at the dealership. I am not a mechanic and never would pretend to be. I know that many people have had this problem and it seems like the consensus answers don't fit here. Other than what has already been eliminated as the source of the noise, does anyone have any hypothesis as to what this could be? Thank you in advance. 

[papageoff]

My first thought was u joint, but you said you covered that. You don't have anything rolling around in the bed do ya? ;). Sorry I'm not much help.

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[sac55]

Lol no. Turned out that the crossmember had somehow become warped and when the engine torqued, the skid plate was hitting the transfer case. I guess this is why the sound was intermittent. This is probably the last thing I ever would have expected. The damage was underneath the skid plate and it looked fine when everything was still. That’s why when I would get underneath the truck to look at it, everything looked fine. It was only discovered once the skid plate was removed. 

[Julio2121]

My sierra is making the same noise, I just got the transmission rebuilt. Only started happening when I got it back. How did you get it fixed? Did you get a new skid plate. 

[Borntorun]

I'm not sure this same thing op posted about for about the last month I was hearing a clunky / creeking sound from under my front end of my 18 Sierra with 7000 miles. I made appointment with dealer and took in last week . The mechanic heard sound and found that my frame cross over member and lower control arm bolts needed to be re-torque. Problem solved !

 

 

[Scott14360]

I have 2011 gmc sierra 1500 4x4. It made clunking sounds on acceleration. I found when I changed drive setting from auto to 2wd it stopped the clunking sounds. I believe the sensor or 4wd auto control is jumping on and off. Not certain,  but it stopped in the 2wd position. 

[Ctexas]

On 3/10/2021 at 6:49 AM, Julio2121 said:

My sierra is making the same noise, I just got the transmission rebuilt. Only started happening when I got it back. How did you get it fixed? Did you get a new skid plate. 

Mine is doing the exact same thing and just had my transmission rebuilt. Did you ever figure out what it was?