I have been trying to figure this issue out for a little over a month, and am completely stumped. Hoping someone has had this issue. When I drive my truck over 45 miles an hour it begins to sway pretty badly to the left and right. Similar to sway as though you were pulling a trailer with no tongue weight but I am empty and clunks when turning left that I can feel in the driver floorboard. all upper and lower ball joints done with moog, new track bar, new stabilizer, new control arm bushings, new tie rod ends, sway bar is in good condition. I’ve inspected the u joints and inspected drive shaft. The truck has been aligned by two shops and looked at by two shops and nobody has any answers but say the truck is scary to drive if that helps to understand the extent of the issue. And I am at a complete loss. Any input is appreciated!

 

Have you checked the wheel hub bearings closely? Also, is the steering gearbox good and tight or is it sloppy?

 

I have not looked too closely at the hub bearings i did not suspect that could cause sway. The gearbox is tightened as it should be minimal play in steering wheel. however it is the oem gearbox. I was considering a redhead gearbox in the near future.

 

Can you drive behind it to see if it's crabwalking? How are leaf spring bushings and rear shackles? Rear u-bolts aren't rusted through?

 

I will be honest I have been so fixated on the problem being in the steering that I have not looked into the rear. I will be working on it in a few hours and will go through the rear end as well as inspect the wheel bearing.

 

Does it just have a bad case of the wanders? Hard to drive in a straight line? Do you feel the rear end moving in directions you don't think it should? Do you have the heavy duty steering on your truck? Is there any slop in the steering at all?

 

I don't really feel the rear end moving, the best way to describe is when you get about 45 it will start to pull in one direction, not left or right specifically it is random and lets say it pulls left then ill slightly adjust the steering wheel to compensate for the pull then it will start pulling right, so it constantly needs corrected and its bad enough to where it looks like I just got done drinkin a 12 pack and am tryin to drive home. and no play in steering, last shop i had it in adjusted the gearbox and stated it did not appear there was any faults in gearbox.

 

Have the alignment shop increase caster angle. That will help the truck want to actually go in a straight line.

If you have the heavy duty steering, have someone rock the steering wheel gently back and forth (engine off) and see if you are getting tie rod roll. (the link from one side to the other rolls instead of turn the tires for a couple inches of steering wheel movement.)

 

Have you changed your shocks recently? Mine were weak and allowed the truck to have a light bounce/wander. I replaced all 4 shocks with heavy duty replacements and made a world of difference.

 

Update, I went through most of the truck, everything except wheel bearings, changing the rotors tonight because one is pretty bad so when i have to have the wheel bearings out anyway i will inspect wheel bearings, the only thing out of order i could find was when twisting the tie rods that come off gearbox they will easily twist forward and back, but i do not get any left to right movement. And atomicdog, i have not had anything done with shocks since ive owned the truck, since 2019, and before that im sure it was ages, truck was wrecked and sitting in a field in Oregon when i bought it.