Guy Sponaugle

UPDATE!!!!!!!!!!!!!!!!!!!! So I took my truck to a local mechanic (not a dealer) they figured it out for me. It ended up being the transmission after all. GM FINALLY admitted the problem too and now offer a cooler running transmission thermostat which I went with another option found on Amazon for 40 bucks that makes the transmission run about 40'F cooler. Basically my fluid was totally burnt despite having paid for a trans service at the dealer just a couple years ago. This time per my mechanics recommendation I had them add a Lucas additive. No more vibration. and no new $7,000 transmission.

I am with you on this issue. I have been dealing with it since I bought the truck a few years ago. At first I thought it was power steering humming but it has gotten worse and worse. I have a 2014 1500 Denali 6.2L, 6L80E. I have since redone the entire top end deleting the DOD and it still does it. Dealer said they dont know what the noise and vibration is but that I need to replace the entire transmission and converter. It shifts fine though so Im not dropping $7,000 on that just to see if it helps. Please let me know if you find anything and I will do the same. It is definitely not engine related as in my case it does it regardless of engine RPMs. at slower speed its to a point it rattles loudly and at high speeds it it hums and vibrates usually only under slight load like on a gradual hill and under small amount of throttle and I can cause and stop it at any time by applying and removing small amounts of throttle. Ive got new tires, new brakes, and new top end and still it persists. I am thinking U-joints or drive line at this point. or something in connection with those parts.