Truck steering veers to both left and right after new tires and alignment

Hello All,

I drive a 1997 Ford F150 4x4, 4.6L pickup with around 165,000 miles on it. The problem I am having is that the steering does not seem to want to stay straight ever. If I have the steering wheel in the center position, it sometimes veers to the right, and other times to the left.

This happens everywhere, highway or street. It is sort of consistent: For instance, on the highway, if I’m in the right lane, the truck veers to the right, in the left lane it veers to the left. It seems to have to do with the angle of the road, the highway is not 100% flat, there is a slight angle for water runoff. I realize the truck would veer a little, but this seems excessive (I have to correct the steering by 1/8 of a turn).

Everything was fine a few weeks ago until I changed the tires. I did the following work:

* Replaced lower ball joints (front, both left and right)

* Replaced upper ball joints (front, both left and right, arm assembly)

* Replaced all four tires with General Grabber AT2 tires (same size as original tires)

* Balanced tires

* Got an alignment done, according to the alignment everything is where it’s supposed to be

Before I replaced the ball joints, the truck seemed to steer just fine (straight). After I put the ball joints in, the steering was way off to the right (I was told it was off by full 2 degrees). Then they aligned it, and it seemed fine, until I noticed the left/right veering.

I had a tire shop do the alignment and balancing, but the ball joints I replaced myself before the alignment.

What could be causing this?



Logic dictates that we look at what was changed and assume that something was damaged or left loose or new defective.

However, before we go there, lets look at the rear trailing arm bushings. If the rear axle is shifting around, it will cause the truck to steer from the rear like a fire truck, which can cause it to drive the way you describe. The alignment shop could easily have missed this problem.

Assuming the toe and camber adjustments are correct, what about the caster?
The caster is something that is often overlooked and can cause pulling.