Bullfrog154

Just picked up my truck from the dealership. While testing them on the load balance machine they discovered that both front tires were out of tolerance. They replaced both front tires And load balanced them. So far, the truck rides much better. It's not perfect but substantially better. The tires are Goodyear Eagle LS-2, P275/55R20's. I'll be making a long distance run within the week so time will tell. I'll keep y'all posted.

Let us know what the driveline shop says. Mine is going in to the dealer in morning for load balancing. I seriously doubt this will improve the vibration issue.

After reading all the comments on this site, I'm going to request the dealer to load balance the tires, preferably with me there!

That would make me lean towards the problem either being tire related.

I just purchased a 2016 GMC SIERRA 2 wheel drive SLT pickup with the Crew Cab and the 6 1/2 foot bed. It test drove good around town but after purchasing it and getting it on the highway, I noticed a substantial vibration between 70 & 80 mph. Took it back to the dealer on Monday October 31, 2016 to have the bed liner sprayed in. Mentioned to them the vibration problem. The sales rep. had one of their techs test drive it and he agreed the vibration was substantial. They balanced the right rear tire and said it appeared to be better. They also mentioned that this is a truck and I should expect some vibration! When I test drove it, it didnt really feel any better. I plan to take it out on a smooth section of highway in the morning to see how it rides. One thing I thought I noticed was that at 75mph on smooth flat surface my truck was vibrating substantially but I sensed when I started going up hill, it seemed like the vibration began to subside. I tried to repeat this but it did no seem to subside when going uphill. Has anyone checked the pinion to transmission angles? I checked mine using the Tremec transmission smart phone app. It indicated my angles were all good. Has anyone compared the pinion to transmission angles of the trucks shaking versus trucks that dont shake? Has anyone placed a load in the bed to see if it makes any difference in the vibration? I've spoken to three others that own similar trucks and they don't have the vibration problem. I did find that one of my friends that lives 400 miles from me, had purchased a GMC pu almost identical to mine and went threw all kinds of difficulty working with the dealer because his was experiencing similar vibration; balanced tires, replaced tires, etc and never solved the problem. He sold the truck and purchased a Tundra. GM has lost that customer for good! I wish us all well with coming up with a resolution.

I just purchased a 2016 GMC SIERRA 2 wheel drive SLT pickup with the Crew Cab and the 6 1/2 foot bed. It test drove good around town but after purchasing it and getting it on the highway, I noticed a substantial vibration between 70 & 80 mph. Took it back to the dealer on Monday October 31, 2016 to have the bed liner sprayed in. Mentioned to them the vibration problem. The sales rep. had one of their techs test drive it and he agreed the vibration was substantial. They balanced the right rear tire and said it appeared to be better. They also mentioned that this is a truck and I should expect some vibration! When I test drove it, it didnt really feel any better. I plan to take it out on a smooth section of highway in the morning to see how it rides. One thing I thought I noticed was that at 75mph on smooth flat surface my truck was vibrating substantially but I sensed when I started going up hill, it seemed like the vibration began to subside. I tried to repeat this but it did no seem to subside when going uphill. Has anyone checked the pinion to transmission angles? I checked mine using the Tremec transmission smart phone app. It indicated my angles were all good. Has anyone compared the pinion to transmission angles of the trucks shaking versus trucks that dont shake? Has anyone placed a load in the bed to see if it makes any difference in the vibration? I've spoken to three others that own similar trucks and they don't have the vibration problem. I did find that one of my friends that lives 400 miles from me, had purchased a GMC pu almost identical to mine and went threw all kinds of difficulty working with the dealer because his was experiencing similar vibration; balanced tires, replaced tires, etc and never solved the problem. He sold the truck and purchased a Tundra. GM has lost that customer for good! I wish us all well with coming up with a resolution.