Shadetree TJ Alignment


Installing a lift will screw up the toe-in, caster and steering wheel centering. You can adjust these fairly close to spec yourself. Here's how to make these adjustments yourself.

For the text below, refer to this picture:


Steering Components Detail

Toe-in
When you install a lift, you raise the drag link and thus raise the tie rod. This greatly increases the toe-in. Improper toe-in can dramatically increase tire wear and cause death-wobble, so adjust this before you drive anywhere.

Your front tires aren't normally supposed to be parallel, at least not while parked. The distance between the front of the tires should be less than the distance between the back of the tires. This is called "toe-in" or "toed-in". Take a measuring tape and a helper and measure the distance between the front of the tires and the back of the tires. I like to use the tires' mold seam. It is important to use the same point on the tread for both the front and the rear measurements. After much experimentation though, we have found that the front measurement should be from 0 inches to 1/8 inch less than the back, as close to 0" as possible without toeing out.

To adjust toe in, loosen the tie rod sleeves on both sides using a 13 mm wrench. Rotate the tie rod and remeasure until you have about 1/8 inch of toe-in. I use a big pipe wrench to turn the rod. If you are concerned about appearance, you will have to experiment to find something that won't scratch your rod.

Caster
Caster is the relationship between the steering axis and tire vertical. Look at how a bicycle fork is mounted at an angle; this is caster. Zero caster is when the steering axis is vertical. When the steering axis is tilted backwards it is said to have a positive caster. Caster angle is important for steering stability and handling. If the angle is too low or zero you will feel your Jeep trying to oversteer in a turn rather than returning to straight. You may feel your Jeep wandering rather than holding straight and true. Improper caster can be dangerous. Incorrect caster can also cause drift or pull to the left or right. Unequal caster from side to side causes steering pull to the side with the least amount of positive caster. With any lift, if you don't change the length of the control arms, the caster angle will be reduced.

Caster is changed by rotating the cam bolts on the axle end of the lower control arms. I have only seen these on '97 and '98 TJ's, so you might be out of luck or be forced to install adjustable control arms. Since this rotates the entire axle, this also has the effect of changing the pinion angle. This generally isn't a problem on the front though because of the long drive shaft.

Measuring the caster angle requires professional equipment. If you have lifted your TJ and have the adjustable cam bolts and do not have longer or adjustable control arms, you might want to adjust them out. On my approximately 4" of lift, I adjusted the cams as far out as they would go since I do not have adjustable or longer control arms. This works great for me.

When you test drive, note if your Jeep tends to pull to the right or left. Try to find a flat straight road with as little crown as you can find. The crown of the road might cause you to drift a little to the right, and this affect is magnified by larger off-road tires. So a little drift to the right is OK. If it pulls to the left or right, you need to increase the caster angle on the side it pulls to. Do this by rotating the cam forward. If you find you've rotated the cam all the way forward and still get pull, you'll have to rotate the other cam back some. Without the adjustable upper control arms, you may very find that one side or the other needs to be fully adjusted to get it in spec.

Camber
Camber is the measurement of the angle of the tire from vertical when seen from the front or rear. Your Camber cannot be adjusted obviously since your wheels are mounted to a fixed axle. If you have a camber problem, something's bent!

Centering the Steering Wheel
When you install a lift, you raise the drag link. This will cause your steering wheel to rotate. This is easy to center but takes some trial and error. Do this after setting the toe-in.

With the tires pointing straight ahead, loosen the turnbuckle on the drag link with a 15 mm wrench. Rotate it so that the steering wheel is centered. It helps to have a helper watch the steering wheel while you do this. When centered, tighten the turnbuckle and go for a test drive. Odds are, it won't be quite right. Just tweak it a few times and test drive. Be sure when done that the sleeve bolt heads are facing forward. This will prevent any possible contact with the track bar. You may need to rotate the sleeves (not the turnbuckle) to do this.