2015 Silverado Vibrates badly between 71-80

[halld59]

I have a 2015 Silverado Z-71 6.2 4X4 that was towed from the rear after the fuel pump died. When I picked the truck up from the dealer and hit the interstate, I accelerated to 70 and when I hit 71 the truck felt like it was going to come apart until I reached 80. Returned to the dealer and after 2 months, the truck is still on the rack. For full disclosure, the rear end has been rebuilt twice and the cause for those rebuilds were from me pulling too much weight and a bad rebuild at the dealer. Any ideas?

[CamGTP]

Bent axle or out of balance driveshaft come to mind.

[halld59]

I let the dealer use the driveshaft from the 2015 Silverado and put it in my 2018 Silverado and no vibration. That rules out the driveshaft. In fact, I just had them leave the 2015 driveshaft in the 2018 as I was in a hurry. Supposedly the dealer was getting a tool to test my axles.

[halld59]

I may let the dealer swap axles at this rate just to see. If that is the problem, they can replace them under warranty. They should just replace the entire rear end assembly with as much work that has been done to it.

[David Wallace]

8 hours ago, halld59 said:

I may let the dealer swap axles at this rate just to see. If that is the problem, they can replace them under warranty. They should just replace the entire rear end assembly with as much work that has been done to it.

Does it make any noise? like a hummm...quiet.....hummm... quiet....hummmm?

[halld59]

There is no humming noise that I can hear. All  bearings were replaced  when the rear end was rebuilt again 4000 miles ago. One other thing  forgot to mention, the dealer put my spare on the right rear and test drove the truck and he said that it made the vibration in that speed range 10 x worse. I expect that to be the size difference of spare tire and it may be out of balance.

[David Wallace]

5 minutes ago, halld59 said:

There is no humming noise that I can hear. All  bearings were replaced  when the rear end was rebuilt again 4000 miles ago. One other thing  forgot to mention, the dealer put my spare on the right rear and test drove the truck and he said that it made the vibration in that speed range 10 x worse. I expect that to be the size difference of spare tire and it may be out of balance.

Ahh gottcha. I've been having a problem that no one can figure out.

 

At highway speeds mostly 64-68mph but also anything above that speed will trigger a low rumble and slight vibration. The rumble is always there but in a pattern... whoom......quiet.....whoom....quiet.....whoom with about a second in between the whoom and quiet. when I switch to stock wheels and tires it makes a big difference.. but it still does it. when i'm going 80mph and punch the gas it sounds like i'm hitting the rumble strip on the freeway. I HATE THIS TRUCK.

 

Hope you get yours figured out.

[halld59]

I have owned 29 Silverado's in the last 30 years and had 2 lemons in the bunch with the 2015 being one of them. I currently have a 2008 Silverado Z-71 working on 600,000 miles and going strong. My 2018 seems to  be ok as it too new judge. I bought it leftover dealer stock at a steal, I hope that you get your problem resolved as well

[halld59]

UPDATE, After several nagging trips back and forth to the dealer, I finally have the answer. They are going to replace the entire rear end assembly due to all of the previous work. Stand by for updates