1988 Jeep Wrangler - How do I do a DIY alignment?

Question

Have a friend with a '88 YJ. He wants us to tackle an alignment job on it. It's pulling to the right.

We can see the rear axle is not aligned and tire rubs on one side. It looks like it might be as much as 1" off.

I've read the forums and have been bitterly abused by them in that no one agrees on how to do it at your home. I know it can be done and done successfully but it probably requires patience and good home DIY alignment tool/methodology.

• Does anyone have any sound advice on accomplishing this?

• Does anyone believe this is an exercise in futility?

Please keep in mind, I do almost everything home brew. I'm not concerned with failing, doing it, failing and then nailing it. I enjoy the process of learning through experience and have done body off restores. I've just never nailed the alignment piece. This seems like a good opportunity to be successful where I've failed in the past.

• I'm interested in the tools, the method and the gotcha's.

TIA

Answer 1

Rear solid axles on trucks especially with leaf springs are not adjustable. To cause enough misalignment for one wheel to rub something must be damaged. I would start by looking at the center bolt of the leaf springs. The bolt ties all the leafs together in the center and is used as an alignment pin with the pad on the rear axle. Everything is held together with the U bolts.

Using a measuring tape measure corner to corner diagonally of the leaf springs to make sure that thy are square and the frame is not warped. Inspect the leaf spring mounts for any damage. Measure from the leading edge of each spring to the axle. If it is not the same, which i suspect, then pull apart the U bolts and inspect the center bolts. Resemble making sure that the axle is now straight and that the spring front to axle distance is the same.

Moving on to the front. The three angles are caster, camber and toe. Without a machine, caster is nearly impossible to measure. With the solid front axle the caster is not adjustable. (see camber)

Camber is a different story, sort of. While there are not active adjustments in your truck for camber it is easy to measure. There are some special off set lower ball joints available that allow changing camber and caster, they are super expensive and a giant pain to use. To measure camber you need a home built jig. In essence the jig is a big carpenters square, where it will sit flat on the ground and reach all the way to the top of the rim. Making it out of wood is easy, just make sure that it is nice and square, it stands up on its own without falling over and that it's taller than the top the rim. On a nice flat concrete surface using a measuring tape measure from the top the the rim to the jig. Then measure from the bottom of the rim to the jig. Make sure to keep the measuring tape nice a parallel to the ground. Just a bit of trigonometry is needed to figure out the angle. Inverse sine of [(top - bottom)/rim diameter]. In your case the actual angle is not important it just needs to be nearly the same on both sides.

Toe is the exact opposite, easy to adjust and a pain in the ass to measure. Your truck has two toe adjustments one is on the tie rod that goes to the steering box. This adjust the steering wheel "straightness." The other tie rod adjust the actual toe. First start by wrapping the center of each wheel with duct tape, several layers may be required. Spin the wheel lightly and use a permanent marker to scribe a line as straight and centered as possible. Using a measuring tape measure the distance line to line in the front and back of the tire. You want to measure exactly the height of the center of the wheel off the ground in front of the tire and in the back. You can use the camber jig you made earlier to help. This is probably a two person job. To adjust loosen the pinch sleeve bolts on the toe sleeve and turn the sleeve. Every time you make an adjustment roll the truck back and for a few times to make sure the tires settled. Adjust it for either zero toe or just the slightest toe in. When that is complete reassemble everything and then loosen the pinch sleeve bolts on the straightness sleeve. Leave the bolts loose and take some tools with you for a drive. Asses how off center the steering wheel is then pull over and tweak the sleeve. Do this util you are happy with how centered the wheel is.

All the instructions that i have given assume that nothing is loose in the front end and that all the rear end problems have been solved.

Answer 2

This may not be a perfect answer, but here's what I know...

I am assuming this vehicle has a solid rear axle. There should be a panhard or track bar that connects the axle to the frame to keep it in alignment. The fault with this bar, is it moves the axle to one side when the suspension is compressed, and the other side when the suspension is not compressed. If the vehicle is raised or lowered, you need to adjust this. There are 2 popular methods - cut and weld, or find/make an adjustable bar.

For the front, you need to worry about toe and camber. Toe is the alignment looking from the top down (front vs back), camber is the alignment looking at the tires from the front of the vehicle (top vs bottom).

For toe, you use a toe bar. drive the vehicle up to the location where you will be doing the alignment. keep the wheel straight. Measure the front and back, then adjust accordingly. Move the vehicle back and forth and measure again. You might be able to build/rig something you can use, but it likely will not be as accurate. In the end, you want to be between 0 and 1/32" toe in.

For camber, you need to measure the angle between the top and bottom of the rim. There are tools out there for this. The magnetic ones connect to the rotor so you can set your camber the same as it was after changing shocks. Not sure if I would trust this for setting the camber. might be able to use it to make sure they are the same.

At home alignments are OK to get it in the ballpark, but I would highly suggest getting a shop with a proper machine to do the alignment. They usually have a deal when you buy a set of tires.