Strong vibration from 50mph-55mph on my 9900i

[Redland1]

I have a bad vibration on my 03’ 9900i from 50mph-55mph.It started yesterday and I’ve never had any other strong vibrations like this one on this truck before.What do I need to look at?

[tree98]

Frozen mud in a rim throwing the wheel out of balance. Does it go away if you push the clutch in ? Bad U-joint, bad carrier bearing. Check for a bad u-joint on the short shaft between the drive axles !!! Get back there and give it a good shake with your hands. When those break loose its a really really BAD day.

[Redland1]

(02-24-2023 )tree98 Wrote:  Frozen mud in a rim throwing the wheel out of balance. Does it go away if you push the clutch in ? Bad U-joint, bad carrier bearing. Check for a bad u-joint on the short shaft between the drive axles !!! Get back there and give it a good shake with your hands. When those break loose its a really really BAD day.

Pushed up on the u-joints and they are all solid.Carrier bearing is intact.And pressing in the clutch doesn’t help.Need to check for frozen snow.

[victory26]

May be your kingpins. Also check your ride height . A leaky or damaged leveling valve can cause that.

[Redland1]

(02-25-2023 )victory26 Wrote:  May be your kingpins. Also check your ride height . A leaky or damaged leveling valve can cause that.

I did hear the leveling valve leaking and crawled under the truck and found the long rod coming down from it had play where it attaches at the bottom.Tried to tighten the bolt at the bottom of that rod but it wouldn’t move.Going to have to cut it and put a new bolt when I finish my shift.Zip tied it we’re it doesn’t have any play for now.