backyard alignment issues help...

Alright I am changing TRE's and went to an adj trackbar finally.
Well I am doing the alignment and cant for the life of me figure it out. I am just working on the toe in and out.

I have it parked with the tires straight and measure from the front inner most part of the sidewall to the opposite tire same spot. and then do the same to the back of the tire. Its within and 1/8 of an inch. then I checked from the inside of the rim front to the other side and ditto on the rear still same 1/8" of difference. Then went to inside of the middle lug on both tires and then the rears as done before and still the same.

Now is the tricky part I can step back about 15feet and tell without a doubt that the tires are going away from each other. My question is how in the hell is this possible? I am not doing it on pavement it is on the dirt in the backyard so could that cause the difference or the tires to sit different? thanks for all your help
DIG IT!

Try using the GoJeep method and you can't go too far wrong: http://go.jeep-xj.info/HowtoAlignment.htm.

I think you're seeing an optical illusion based on parallax error, but if I were you, I'd check your measurements somewhere on the hard.

Yep - it's all in your head. When you look at the front tires from even a longer distance away, you aren't looking at either of the front tires front straight on. You're looking at the inside edges of both front tires. Combine this with the fact that objects further away from you appear to be smaller and converging toward a point far off in the distance (even though the rear edge of the tires is not that much further away from you than the front), and your brain tries to convince you that the tires are pointing away from each other.
Just ask your brain whether you can really judge "by eye" a difference of 1/8" from 15 feet away more accurately than you can by using a tape measure?

I just did the same alignment last weekend. If I didn't just do the alignment, I would have sworn the tires were pointing away from each other too. Trust me though, its an optical illusion. Drove mine to work today (35's, 8+" of lift) and it rode perfectly. I set the cruise control for 75 with no problems.

HTH's
Andy

Each front fender on an XJ comes inward a couple inches making the front clip of the XJ narrower than the main body. Since the tires are practically straight ahead the fenders coming in makes the tires look like they are pointing outwards.

Bender said:

Each front fender on an XJ comes inward a couple inches making the front clip of the XJ narrower than the main body. Since the tires are practically straight ahead the fenders coming in makes the tires look like they are pointing outwards.

Click to expand...

Not much fender left I guess its just my imagination. I measured it on pavement and its about an 1/8" off. So disregard that post I guess.

Now where is the damn vibration coming from its steering oriented.

You can always just run some string by tying it to the leaf spring and then running it over the middle of the rear and front tyres when pointing straight ahead and you will soon know. Do it on both sides to make sure you have the wheels pointing straight ahead. I would lose the 1/8" of an inch though as have had trouble with leaving that much toe in before on some sensative Jeeps!