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Discussion Starter · #1 ·
I have a 2012 Silverado 4x4 running 33" that I just bought. Ive noticed a weird vibration in the truck lately that seems to be getting worse. Ive narrowed it down to only doing it when slowing down and i see the RPM needle down shifting. it seems to be the transmission or torque converting im thinking. At first I thought it was the brake rotors, but now I see it happens right when i feel the truck down shift in every gear. The truck vibrates enough to shake me in the seat from side to side. Thoughts ??

I'm over the mileage on the full warranty, but still under the drive train. I think I need to take it in, but curious if this is common or been heard of.
 

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I have a 2012 Silverado 4x4 running 33" that I just bought. Ive noticed a weird vibration in the truck lately that seems to be getting worse. Ive narrowed it down to only doing it when slowing down and i see the RPM needle down shifting. it seems to be the transmission or torque converting im thinking. At first I thought it was the brake rotors, but now I see it happens right when i feel the truck down shift in every gear. The truck vibrates enough to shake me in the seat from side to side. Thoughts ??

I'm over the mileage on the full warranty, but still under the drive train. I think I need to take it in, but curious if this is common or been heard of.
Still sounds like rotors to me
 

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Discussion Starter · #5 ·
I was able to troubleshoot it last night. If I stay manually in first gear and speed up, then as I slow down i don't feel the vibration. If i do the same thing in auto drive getting up to the same speed, when i start to slow down and it shits from 2nd to 1st, i feel the vibration.
 

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Really ?? Its only when the truck down shifts.
Yes. The tq is applied differently to the bearing when under power. Or all your lugs a loose. I have had that cause a vibration only under decel before. I am not saying it is the answer but it's worth checking and far cheaper than Trans work
 

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Discussion Starter · #7 ·
Yes. The tq is applied differently to the bearing when under power. Or all your lugs a loose. I have had that cause a vibration only under decel before. I am not saying it is the answer but it's worth checking and far cheaper than Trans work
Lugs are good. How long do bearings typically last ? truck has 40K miles on it now.
 

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Discussion Starter · #9 ·
So, took the truck to the dealer yesterday and the Service manger did a test drive. We found the truck was vibrating when it was switching from to the V4 mode from V8 mode during down shifting. With the 34" tires, he thinks the tranny is trying to adjust at the wrong time and he recommended me to get a programmer to change the computer. So, last night I ordered a Superchips Flashpaq Tuner to make some adjustments. We shall see if that fixes it. The Superchip tuner can turn the V4 mode completely off as well as change shift points.
 

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Discussion Starter · #10 ·
Update, tuner was able to turn off the V4 mode switching, but vibration is still there. Called the dealer and spoke with service manager. He said it could be the lift kit drive line angles are causing this since its only happened when slowing down. Might need to shim it. So, guess I'll be taking it back to lift kit shop to have them verify it. Starting to get frustrated with this. :(
 

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Discussion Starter · #12 ·
Check your trans mount and the rear driveshaft U-joints
Will do, taking it to my buddy's off road shop today to go threw it all. If he says it all looks good, it goes back to dealer. I did check my U-Joints and have no play in them. Seems fine.
 

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Discussion Starter · #13 ·
SUCCESS !! My buddy at Planet Pickup found the problem. The damn rear 3" blocks were in backwards pointing the axle down. Flipped them around, test drive and vibration is gone.
 
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