St2002walker

If you are suggesting that the vibration is coming from the front end from a rotating imbalance, which I agree with, has anyone looked into possible issues with the front wheel hubs?

Yeah man, I'd definitely be interested in knowing the state of your body mounts. I feel my right rear one being cracked could allow the truck to bounce up and down, making it seem like a vibration. Something else I've noticed is that I do not have very much space in between my overload spring and my leaf springs. I wonder if the overload could be making contact with minor road bumps, when it shouldn't be. I have noticed similar vibrations to what you described. I drive a highway home from work everyday, 69 mph and I get the vibration. On that 20 mile trip home the vibration will completely go away and it drives like a normal truck, then it will come back. That's why, with my truck anyway, I don't feel something is out of balance, bend, or out of round. If any of those were true, the vibration would always be there. Could you post some pictures of your right rear, or left rear bodymount bushing? And can you post a picture of your leaf springs, to show the distance from the two leaf springs to the overload spring? Thanks! History on my truck: 2016 slt, 1500 6-speed 3.42 gears. 34" Michellin LTX (non-agressive tread), Lifted 4.5" with a zone offroad lift and 5" rear lift block instead of the 4" lift block that came with it.

Hey Olvim. I have a similar truck, 2016 sierra slt, 3.42 gears but with 20's. Do you know, or can you find out if your truck was assembled in Mexico? (Silao?) Everything you described as far as vibration is very similar to what I have. Do you have a lift? What all did the mechanic "tighten" up as far as front suspension? I looked under my truck at all of the cab body mount bushings and noticed out of the six that connect the cab to the frame, my right rear body mount bushing is cracked. Has any one else experienced this? Thanks!

Can you tell me what is the test to determine if you need a 3 mm shim for the engine mount?