2020 Trail Boss highway vibration

[mikewz71]

Hello all,

 

-2020 1500 LT Trail boss 5.3/10spd with ~40k miles

 

Problem is I have a slight vibration on the highway that feels exactly like an out of balance tire usually from speeds ~75 to 80mph, sometimes randomly between 70-85mph. Not always at a consistent speed. 

 

General timeline of events:

 

Stock duratracs were getting obnoxious at ~39k. I remember noticing a vibration on those, but dismissed it as worn out tires, and didn't note what speeds it was doing it.

 

Replaced the goodyears with BFG K02 (285/65r18, E rated) and had a vibration on the highway that I definitely noticed due to the tires being new and expecting a smooth ride. Took it back to discount tire and they said "we've had issues with these being hard to balance, nobody warned you not to buy these? Pick another brand".

 

Replaced them with Nitto Ridge Grappler in the same size as above BFGs. Same highway vibe, but rough ride on highway too. Took it back and they rebalanced them, the vibration was about the same but ride was slightly better. 

 

Discount tire said "you have had two sets of premium tires with a vibration, go get the truck checked out"

 

Tried driving in L9, shifting gears, putting the truck in neutral, still shakes.

 

Put the rear end on stands and ran it up to 80mph, smooth as glass.

 

Decided to swap wheels and tires with the wife's truck (2019 1500 with 20" wheels/dueler ATs, almost worn out) and the vibration was there, just not as bad. Harder to detect. Led me to believe it was the truck, not the tires.

 

Took the truck to the dealership, they inspected everything underneath, said everything looked good but found the tires had excessive road force, one over 100lbs. They lowered all but one below 30. Wheels required a lot less weights now. Ride quality got noticeably better, but highway vibe still there. 

 

Took it back to discount to get them to reimburse me for having to pay for a road force balance at the dealer, they had to take a look to verify what they did. They got the other tire down below 30 on the road force, and replaced a tire because it looked "off" while spinning. Ride is even better, but still vibrates at aforementioned speeds.

 

Definitely seems the worst in the morning. The interstate is a mile from the house, so I'm wondering if it's a flat spot issue, but still does it on a road trip.

 

So I'm not 100% convinced that it's the tires, and may take it back to the dealer to have them double check, but I'm afraid they're going to just blame the tires again.

 

I do have a trans service coming up, but seems like all the vibe issues that are trans related are with the 8speed.

 

Thank you for your time, I know it's a long read but I've been pulling my hair out trying to get this straight.

 

Anything I should look for or anyone have any similar experiences? 

 

Edited April 10, 2024 by mikewz71
Details

[Bikerjon]

On 4/10/2024 at 9:02 AM, mikewz71 said:

Hello all,

 

-2020 1500 LT Trail boss 5.3/10spd with ~40k miles

 

Problem is I have a slight vibration on the highway that feels exactly like an out of balance tire usually from speeds ~75 to 80mph, sometimes randomly between 70-85mph. Not always at a consistent speed. 

 

General timeline of events:

 

Stock duratracs were getting obnoxious at ~39k. I remember noticing a vibration on those, but dismissed it as worn out tires, and didn't note what speeds it was doing it.

 

Replaced the goodyears with BFG K02 (285/65r18, E rated) and had a vibration on the highway that I definitely noticed due to the tires being new and expecting a smooth ride. Took it back to discount tire and they said "we've had issues with these being hard to balance, nobody warned you not to buy these? Pick another brand".

 

Replaced them with Nitto Ridge Grappler in the same size as above BFGs. Same highway vibe, but rough ride on highway too. Took it back and they rebalanced them, the vibration was about the same but ride was slightly better. 

 

Discount tire said "you have had two sets of premium tires with a vibration, go get the truck checked out"

 

Tried driving in L9, shifting gears, putting the truck in neutral, still shakes.

 

Put the rear end on stands and ran it up to 80mph, smooth as glass.

 

Decided to swap wheels and tires with the wife's truck (2019 1500 with 20" wheels/dueler ATs, almost worn out) and the vibration was there, just not as bad. Harder to detect. Led me to believe it was the truck, not the tires.

 

Took the truck to the dealership, they inspected everything underneath, said everything looked good but found the tires had excessive road force, one over 100lbs. They lowered all but one below 30. Wheels required a lot less weights now. Ride quality got noticeably better, but highway vibe still there. 

 

Took it back to discount to get them to reimburse me for having to pay for a road force balance at the dealer, they had to take a look to verify what they did. They got the other tire down below 30 on the road force, and replaced a tire because it looked "off" while spinning. Ride is even better, but still vibrates at aforementioned speeds.

 

Definitely seems the worst in the morning. The interstate is a mile from the house, so I'm wondering if it's a flat spot issue, but still does it on a road trip.

 

So I'm not 100% convinced that it's the tires, and may take it back to the dealer to have them double check, but I'm afraid they're going to just blame the tires again.

 

I do have a trans service coming up, but seems like all the vibe issues that are trans related are with the 8speed.

 

Thank you for your time, I know it's a long read but I've been pulling my hair out trying to get this straight.

 

Anything I should look for or anyone have any similar experiences? 

 

Rear driveshaft u joints? Look for any signs of rust around bearing cup seals. Better yet remove the shaft and roll the u joints through their range of motion and feel for roughness.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

seals

[Grover67]

My '20 AT4 I started noticing a slight vibration before 20k and was getting slightly worse with the more miles. Found that the brake rotors were getting a buildup from the pads. Finally had enough around 30k and replaced all and vibration is gone. There was alot of pad left when I changed them and the wear indicator was at 89% front, 91% rear. The outside of rotors looked good but backside looked and you could feel the buildup. The pad material the GM is using is causing this, due to certain state regulations. Had to take the truck in to the dealership to get the pad wear indicator reset. Asked the mechanic if he has seen this issue much and he has and said just turning them won't help because its the pads. 

 

-Grover67

 

 

[mikewz71]

10 hours ago, Bikerjon said:

Rear driveshaft u joints? Look for any signs of rust around bearing cup seals. Better yet remove the shaft and roll the u joints through their range of motion and feel for roughness.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

seals

Thanks, the rearmost joint does look dirty, I'll check it out.

 

3 minutes ago, Grover67 said:

My '20 AT4 I started noticing a slight vibration before 20k and was getting slightly worse with the more miles. Found that the brake rotors were getting a buildup from the pads. Finally had enough around 30k and replaced all and vibration is gone. There was alot of pad left when I changed them and the wear indicator was at 89% front, 91% rear. The outside of rotors looked good but backside looked and you could feel the buildup. The pad material the GM is using is causing this, due to certain state regulations. Had to take the truck in to the dealership to get the pad wear indicator reset. Asked the mechanic if he has seen this issue much and he has and said just turning them won't help because its the pads. 

 

-Grover67

 

 

Did you have any change in vibration when you applied the brakes? Or feel it in the pedal? Braking doesn't seem to change anything on mine.

[Grover67]

If would get slightly worse and depending how much they were used. Not hard on them but when I was on a trip and went through the Appalachian MTs. and  was using them more it was making it worse, felt it more at certain speeds too. Thought the same as it could be a balance or wear issue, it isn't leveled, so when I did a oil change and rotation I checked the rotors and found the buildup. 

[mikewz71]

Good to know. Was it worse front or rear?

[mikewz71]

Pulled the driveshaft, the rear joint is fairly stiff on one axis, but looser the other way, noticeably so. Front joint is the same way.

 

Not sure if that's enough to make a vibration, but I'll probably replace them anyway. 

[Grover67]

Felt like more in the front but could feel the feedback throughout the drivetrain. After reading that some were having their brakes wear out prematurely I'd thought I'd investigate more. After seeing the backside of the rotor and conversing with a bud of mine that works at GM testing decided to change out the fronts first which took most of the vibration out but the rears(pic was the rear rotor) was looking like the fronts and could still feel it some, so just decided to get over with and change them out and move on. The rears are abit trickier to do than the fronts due to the electric parking brake. 

 

Never thought I'd have to change them out with such few miles and the way its been driven. Chased a vibration issue with my last vehicle but it was deeper in the front axle than I was willing to go at the time.

 

Has your truck had anything done other than change of rubber? Level, different rims/offset, or suspension?

 

Good luck with your quest!

Edited April 14, 2024 by Grover67

[mikewz71]

18 minutes ago, Grover67 said:

Felt like more in the front but could feel the feedback throughout the drivetrain. After reading that some were having their brakes wear out prematurely I'd thought I'd investigate more. After seeing the backside of the rotor and conversing with a bud of mine that works at GM testing decided to change out the fronts first which took most of the vibration out but the rears(pic was the rear rotor) was looking like the fronts and could still feel it some, so just decided to get over with and change them out and move on. The rears are abit trickier to do than the fronts due to the electric parking brake. 

 

Never thought I'd have to change them out with such few miles and the way its been driven. Chased a vibration issue with my last vehicle but it was deeper in the front axle than I was willing to go at the time.

 

Has your truck had anything done other than change of rubber? Level, different rims/offset, or suspension?

 

Good luck with your quest!

All stock but the tires. From what I can see on the back of the rotors through the dust shield, they look good, at least compared to yours.

[Bikerjon]

5 hours ago, mikewz71 said:

Pulled the driveshaft, the rear joint is fairly stiff on one axis, but looser the other way, noticeably so. Front joint is the same way.

 

Not sure if that's enough to make a vibration, but I'll probably replace them anyway. 

You are going to have to start the process of elimination. Sucks but Discount tire nor your dealer has been any help.

[mikewz71]

10 hours ago, Bikerjon said:

You are going to have to start the process of elimination. Sucks but Discount tire nor your dealer has been any help.

I'm definitely willing to throw $50 worth of U joints in it before I drop it off at the dealer for a few days.