Have a 2013 Silverado regular cab short bed 2WD with 4.8, about 75K miles. Immaculately maintained FL truck, looks and runs great except it has a stubborn thunk/clunk when driving, moving slow, parking it, backing up, turning, etc. It will happen when turning the wheel slightly or even going straight just after or even before applying the brakes. Seems load related and only happens when the truck is moving slowly. Will not happen is the truck is stationary bouncing the suspension up and down or by just turning the steering wheel. Can't find it and a good local shop can't find it. Have replaced many parts so far- new steering rack, front wheel bearings, new master cylinder, new front calipers, new brakes all around new front brake lines, new slip yoke and U joints, new stabilizer bar bushings. Front end and all parts are very tight- ball joints, tie rod ends no play. Truck tracks laser straight. Invested over $4500 so far thinking we nailed this clunk and cannot find it. It is so intermittent and cannot be predicted when it will happen to even listen for it outside the truck. Wondering if anyone has run in to this and what else to check before we just drop another 2- 3K replacing more front end parts................

 

Anyone? This clunk has me baffled. I have over 45 years experience and have always found clunks eventually- some took time but I got them. But this one I simply cannot find and it is not consistent enough to hear when it's going to happen.

 

How loud is the clunk? From what you have stated the only thing left is the transmission.

 

It's like a soft clunk and definitely coming from the front end and it's so intermittent. Sometimes right after you apply the brakes, sometimes not. Sometimes just turning the steering wheel. It does it mostly when pulling in the garage or backing out of the garage. Would ball joints or worn struts/shocks cause this? What about ABS module?

 

I found the clunk/thunk. Sway bar bushings were dry and bolts over tightened. Took them out, cleaned and re-lubed and as quiet as ever now.

 

Glad you finally found it! I just joined the forum a few mins ago and made my first post which also addressed a mysterious "clunk" - mine is slightly different than yours in that I only feel it when I start moving after being stopped. Your post will hopefully help me or a mechanic solve my clunk.
2010 Cheyenne Edition, 4.8L

 

A video on how to replace sway bar bushings.

 

rokman, Check your drivers side motor mount.

 

It has new motor and transmission mounts in it. BTW even though I posted above that I solved the issue, I did not. The clunk is louder now and almost like a bang some times. Happens when turning hard and backing up. Definitely coming from the front. The only thing left to replace is the upper and lower A arms with ball joints- the only moving parts left that have not been replaced in the front, other than the shocks and springs. Unless it is a defective new steering rack or broken or defective new motor mount?