Clunk/Vibration noise in front end after ALL suspension components replaced - steering rack the issue?!

midwestdenaliguy · January 2, 2023

Driving a 2016 Sierra Denali with 170k miles. I noticed a new clunk/rattle that occurred when hitting large enough bumps and/or driving on rough roads. Doesn't matter if I'm turning or driving straight. Speed also doesn't matter, but it's more noticeable when driving straight and going 25-40 mph. It was time to replace ball joints/bushings/coilovers in the front end anyway, so I figured that would take care of the issue. Unfortunately it did not, so the only guess I have left is the steering rack is going bad. I also noticed more than usual play in the steering wheel (granted it's slight) which is listed as a symptom of the steering rack going bad. I swear I have also heard a clunk when the steering wheel is full lock and I am reversing, but I haven't been able to reproduce it lately. Here's everything that I replaced on the front end:

- New coilovers from HaloLifts (2.5" lift). They replaced a previous set of coilovers from them that surprisingly lasted 80k miles - same 2.5" lift.

- New Cognito upper control arms/ball joints/bushings that replaced factory UCAs. I made sure they were designed to replace the factory cast iron UCAs that were installed on my year truck.

- New Moog cast iron lower control arms/balls joints/bushings that replaced factory LCAs.

- New Kryptonite outer tie rod ends on new ACDelco inner tie rods. When replacing the inner tie rods I checked the steering rack to see if the baffles came loose but I do not have them. I found a video of a mechanic who said he had a clunk complaint from a customer when turning and he replaced baffles that came loose inside the inner tie rod boot.

- New ACDelco CV axles.

- New Hellwig sway bar, bushings, and Duralast Gold sway bar links.

I torqued everything to spec and immediately took it in for an alignment after replacing everything. I had the shop double check everything and they said it was all tight. Truck was aligned so I was excited for my better riding, quiet truck. While the ride is smooth as can be now, the clunk/rattle still remains.

I then took it to a GM dealership near me in case the alignment shop and I missed something. They said everything was tight and even did an alignment that came back within tolerance - they didn't have to make adjustments. I had them check to see if there was play and/or noise in the steering rack and they said the bushings didn't move when turning the steering wheel back and forth and they couldn't hear anything on the test drive. I'm guessing they didn't drive over a rough enough road though.

Has anyone had a clunk/rattle when going over bumps get fixed when replacing the steering rack? Not the clunk when turning, but while driving straight. I don't want that to be the issue bc it's so expensive to repair, but it's the only guess I have left due to also having a slightly sloppier steering wheel. I also inspected the wheel well areas and entire front end, but could not find any loose parts. Thought maybe it could be the intermediate steering shaft, but that's quiet when I turn it from side to side. I'm at a loss and open to ideas.

Thanks.

Edited January 3, 2023 by midwestdenaliguy

midwestdenaliguy · January 4, 2023

Ordered upper and lower intermediate steering shafts since it felt a little loose. Figured it's worth a shot since I have 170k miles and these joints are known to wear out and cause clunking noises. Went with the Dorman upper since it's beefier than the GM shaft and has great reviews. I'll circle back with results after I install them. Fingers crossed.