I have a 2017 Chevy Colorado 4x4. About a month ago I noticed an odd noise coming from the front end. It sounds very much like the sound of driving on the rumble strips on a highway though not nearly as loud or as significant as that. It's a vibrating sound and it can be felt under the floor as well as thru the steering wheel.

This noise/vibration is very intermittent. It doesn't happen every time I drive the truck. Shutting the truck off and restarting it seems to stop the problem but I'm not 100% certain on that yet. It is only present when I turn the steering wheel to the left. It is occasionally, even more intermittently, accompanied by a thumping sound...like a part is loose and hitting something...coming from the same area while accelerating. So far I've only noticed it with the transfer case in 2WD. However, it seems to have started after I drove the truck to work and back a day or two in the AWD mode (part time 4x4).

I took it in to the dealer and they couldn't replicate the noise/vibration...exactly what I was afraid of since it's so intermittent. They said they checked the left side wheel, brake assembly, suspension, etc...and couldn't find anything loose, broken or damaged. Today it started again on the way home just as I was driving by the dealership. I was able to snag a service advisor who rode with me and got to hear/feel it first-hand this time.

Any of you mechanical types have any suggestions or ever heard of this before? I don't have a clue what it might be, really, but my guess is it's part of the front differential trying to engage on that side for some reason. I believe it's an electrical system and in my mind that would explain why shutting off the truck and restarting makes it go away. But that's just a wild-ass guess.

I've looked on some forums and it seems that other people have this problem with the earlier gen pickups but I can't find anything recent for the newer models.