dale_gribble

So, I was plagued with the electronic steering gear clunk in my 2015 Silverado with 100k miles. I just bought the truck 2 months ago, and the clunk started to drive me crazy. All of the tie rod ends and ball joints were fine. When I had someone turn the steering wheel, I could hold the tie rod and feel the clunking coming from the steering box. I was pretty much reserved that I would have to change the steering gear. I was a little curious though, where could that sound be coming from? The electric steering gear is worm/gear drive. How could it develop so much slop to chatter and clunk in the box? It didn't make sense. Those are generally zero slop gears. I did notice that the steering box to frame mounting bolts would deflect when the steering was exercised left to right. That was odd. I double checked and all bolts were torqued down. Something was fighting, kind of giving and stopping, it wasn't smooth causing the clunk. I decided to try something and I immediately knew I was onto something. I loosened the four steering gear mounting bolts to the frame (yellow arrows). As soon as I loosened all 4 bolts, the steering gear SHIFTED on the frame. See the red arrow? You can see the circle of the undercoating where the bolt WAS, and it immediately shifted once the bolts were loosened. Light bulb came on. The rubber steering mounts were fighting each other because the gear box wasn't settled on the frame where it wanted to be. I left the 4 bolts loosened and SLOWLY drove down my street veering right and left carefully. I really wanted to make sure the gear box was settled on the frame where it wanted to be. I also didn't want to raise the tires up to do this because I wanted the gear box settled while the truck was on its own weight. I pulled back in the driveway and torqued the four bolts back down. The clunk was immediately gone. Gone. Not reduced, gone. I was very optimistic, so I decided to drive it for a few days and the CLUNK IS STILL GONE. GONE. Perfect steering.

Try and put it in tow mode and see if it changes out of curiosity.