2021 Sierra 2500 shake when hitting bumps

[Lawyered1989]

Hi everyone, first time posting on this forum. I looked all over the place for someone having the same issue as me and it’s pretty rare that I come up empty.

 

i have a 2021 Sierra 2500 at4 diesel 4x4. Ever since I bought this truck with 44k miles it shakes after hitting bumps like manholes, road patches, and is especially noticeable when I roll over speed bumps. The dealer keeps saying they can’t find anything wrong but I can feel it in the seat, under my feet and in the wheel as well. The shake last for only about a second and if I am on track smooth new roads it doesn’t occur. Only when you hit rough or older roads with patch work. Unfortunately my daily commute is full of rough roads where this becomes constant for me and I can’t figure it out. I’ve been under the truck to try and wiggle everything I can looking for play and nothing seems loose to me. The dealer replaced the intermediate steering shaft and I noticed less slop in the steering but the shake after bumps is still there.

 

Anyone out there have this issue?

[bruceb58]

Time for new shocks. Go with Bilstein 5100.

Edited August 10, 2024 by bruceb58

[Lawyered1989]

I swapped the shocks with bilstein 5100s this weekend. the stock ranchos seemed worn but not blown or anything. I definitely feel an improvement and I’m happy I upgraded, but the bobble in the front end is still present. I watched a video about a guy putting the cognitio PISK kit on and he talked about how the holes where the pitman arm and idler arm connect to the drag link often wear and create looseness on these trucks, which the PISK is supposed to correct. I read nothing but positive reports from people installing the PISK kit. There is also a version of the stabilizer mount and damper that works with this kit, which may not be necessary and I would start with the PISK first if I went this route. Also an option is the kryptonite pitman arm brace and the full kryptonite steering system. 
 

Anyone out there put any of these on?