Tmoney76
Member
- Joined
- Apr 11, 2021
- Messages
- 16
- Reaction score
- 12
- Points
- 3
Read through a lot of threads but can't find one that seems to match my specific issue.
2021 Laramie purchased new currently has 94k miles
Mods:
Barely a lift. Bilstein 5100 front strut kit. Reused the OE springs. One notch above factory height. Replaced upper control arms because it was torn down anyway. In the rear I put on the smallest spring spacer I could find. No issues with vibration after the lift. Installed around 45K miles. About a year ago with the KO2 on the truck I was lightly rear ended at a stop light. Was hard enough to bend the bumper and hitch. The truck didn't drive any different than I could tell after the hit.
I put a set of 305/55/R20 KO2 on it in 2023 and put about 50k miles on them. Tire shops were never able to get them to balance out right so this had to have started sometime while those tires were on it because the tires would never balance right guess just never noticed it. Fast forward to 2 months ago I put a new set of 305/55/R20 Nitto Terra Grappler G3 on the truck (SL rated not the E rated). Only other thing is One last item.
At highway speeds all the way up to about 70mph butter smooth, Starting above 70 around 73 up to 80 MPH I get a vibration in the seat and floorboard when it's in overdrive. If I set the cruise and force a downshift using the gear selector on the steering wheel one gear the vibration gets less, force a downshift another gear the vibration goes down more etc but never goes away. If I go up past 80 and set the curise the vibration lessens like it does when forcing the downshift but never goes away. I put the truck in 4wd auto and 4wd high and it doesn't change anything with vibration.
My first thought was tire balance issue until I did the test with cruise set and forced the downshift. I've read some general diagnosis that pointed to U joints or torque converter shudder (shudder typically shows up at lower speeds and the truck is smooth below 70). The rear u joints are pretty rusty but that doesn't mean anything either. They also don't have any slop that I can feel.
I appreciate any feedback. Chasing down drivetrain issues are a challenge.
2021 Laramie purchased new currently has 94k miles
Mods:
Barely a lift. Bilstein 5100 front strut kit. Reused the OE springs. One notch above factory height. Replaced upper control arms because it was torn down anyway. In the rear I put on the smallest spring spacer I could find. No issues with vibration after the lift. Installed around 45K miles. About a year ago with the KO2 on the truck I was lightly rear ended at a stop light. Was hard enough to bend the bumper and hitch. The truck didn't drive any different than I could tell after the hit.
I put a set of 305/55/R20 KO2 on it in 2023 and put about 50k miles on them. Tire shops were never able to get them to balance out right so this had to have started sometime while those tires were on it because the tires would never balance right guess just never noticed it. Fast forward to 2 months ago I put a new set of 305/55/R20 Nitto Terra Grappler G3 on the truck (SL rated not the E rated). Only other thing is One last item.
At highway speeds all the way up to about 70mph butter smooth, Starting above 70 around 73 up to 80 MPH I get a vibration in the seat and floorboard when it's in overdrive. If I set the cruise and force a downshift using the gear selector on the steering wheel one gear the vibration gets less, force a downshift another gear the vibration goes down more etc but never goes away. If I go up past 80 and set the curise the vibration lessens like it does when forcing the downshift but never goes away. I put the truck in 4wd auto and 4wd high and it doesn't change anything with vibration.
My first thought was tire balance issue until I did the test with cruise set and forced the downshift. I've read some general diagnosis that pointed to U joints or torque converter shudder (shudder typically shows up at lower speeds and the truck is smooth below 70). The rear u joints are pretty rusty but that doesn't mean anything either. They also don't have any slop that I can feel.
I appreciate any feedback. Chasing down drivetrain issues are a challenge.
Last edited:
