my right passenger tire is wearing on the outside of the tire. I did my own alignment and eliminated the pull to the right. if I let go of the wheel it goes nice & straight on level surfaces.
I see a long bolt at the top plate that holds the upper ball joint. it looks like there are two nuts on top of that long bolt which runs parallel with the tire.
is that the caster adjustment?
would I need to lift it, loosen those two nuts then loosen the long bolt after I mark it of course.
but, since the tire will be hanging, how do I determine how much to adjust it assuming that is the adjustment?
thx in advance.
To properly adjust caster, an alignment machine is needed. There are old school ways to set camber, caster and toe but unless you have ever done it that way before it can be very difficult to understand.
If you want to see how camber and caster are adjusted, look at the mounting bolts for your upper control arms.
There is a cross-bar that is held down by the control arms bolts. The cross-bar goes across from one control arm bushing to the other. The cross-bar has a serrated edge on the bottom side where the bolts pass through that cut a knife-edge into the frame of the truck to help prevent the control arm from moving after the cross-bar is torqued to spec after an alignment.
Now, a quick alignment class.
Caster does not cause tire wear. Positive Caster helps the wheels return to center after a turn and helps the vehicle drive better. Think of positive Caster while looking at the forks and front tire of a motorcycle. The front wheel is out in front of the handlebars. They are very easy to ride. Now, think of negative caster as the front wheel underneath the seat of the motorcycle. Think of how hard it would be to ride and control it. Caster is an imaginary line that is created by moving the upper ball joint in front of or behind the lower ball joint. The lower ball joint is mounted in a stable position and cannot move because it does not have any adjustments. The upper ball joint is where the adjustments come from. If you drop a string straight down the center of the lower ball joint and compare the location of the upper ball joint in relation to the string, you can see whether it has positive or negative caster. If the upper ball joint is behind the lower ball joint, as in if the upper is closer to the rear of the truck, there is positive Caster. If the upper ball joint is in front of the lower ball joint as in the upper ball joint is closer to the front of the truck, it has negative caster.
With the A-Frame suspension, when you adjust the front bolt only, camber and caster move in the same direction. If you slide the front bolt outwards camber goes positive and so does caster. If you slide the front bolt inward, camber goes negative and so does caster.
If you are adjusting the rear bolt only, when you slide the rear bolt outwards, camber goes positive and caster goes negative. If you slide the rear bolt inward, camber goes negative and caster goes positive.
Camber and toe cause uneven or irregular tire wear.
