sicma99ot

I installed my RE 4.5 lift with adj uca, fixed lca, and adj track bar. Running 32 cooper stt. I took it for an alignment at this locally owned shop where the do lifts and stuff for pickups and jeeps. Well know shop in my city, honist guys, reputable and good ol boys. It took them about 30 minutes to align it. I drove home and noticed it would still pull to the left pretty hard. I called the next day to have them recheck it.

They had it for about 3 hours and said they tried just about everything they could think of but it still pulled to the left. I asked if the track bar was centered. It was if the uca where even. Yes. He said he even tried adjusting it so it would pull right. But no go. So they offered to refund me my money. On the way home I noticed the wheel was straighter and it didnt pull so hard to the left but still slightly.

I got a print out for you alignment gurus

SteveMongr

The caster is still low at 4.2. Needs to be closer 5.5. or generally, the most your pinion angle will allow for.
The thrust angle looks suspicious. I had to lengthen the wheelbase by almost 1/4" on one side to get the thrust right.
What are the numbers referring to on the lower part of page, the 11 and 16?

http://go.jeep-xj.info/HowtoAlignment.htm

sicma99ot

Would my thrust angle be off because my shackles are vertical? I know I need relocation brackets. Im not sure what those last numbers refer to but I will check when I get home.

sicma99ot

I thought I took a better pic but I guess not. I will post a better one later.

I know they atleast took off the right uca, because my jam nut was loose and bolt was loose. But dont know how much they experimented with adjusting them before putting them back to what the had them at before.

SteveMongr

No, the rear axle is held mostly in place and centered by the unhinged front portion of leaf springs and leaf pack bolt/pin.

sicma99ot

How would I adjust that?

SteveMongr

Non-adjustable. Provided the rear axle was centered on the pins when/if installing leaf springs. The only adjustment would be in front axle by means of adjustable uppers and lowers.
However, according to the printout the thrust angle is within spec! And I hear it is not zero because of the 'crown in the roads' or 'vehicle should drift right as to not cross into oncoming traffic..' I don't know..
What I do know is there is 'cross-caster' in the front axle to accommodate the crown in road. It's subtle and can be seen in the numbers on printout.

sicma99ot

Ok i see what your saying. So other than the castor, how is everthing else? The rest is mostly/barely in spec but some are more than others. Any problem there?

SteveMongr

I think it will drive better by simply by adding caster. This usually corrects 'wandering'.

sicma99ot

SteveMongr

Not sure what the secondary angles refer to. I could guess that SAI is Secondary Angle of Incidence. It's a big number whatever it is.
Maybe do some research on it so you can school the alignment guys.
Generally the only adjustment for an alignment is toe and caster. Can be done fairly accurately and easily with a tape measure and angle finder. Then take it to the shop for a printout, usually free if they do not make an adjustment.
I struggled with mine some, dialing it in. That was 2 years ago I and did not use an alignment shop. So far all is well, even tire wear.

tree392

you need more caster, typically optimal specification is between the min and max, so for caster up around 5.5 would be good 6.5 would be better. Your camber is about spot on, and your toe is only off slightly but with a little ocd you get it better. The thrust angle being where it is won't matter with a good toe set. Caster is the main stabilizing angle, so higher the better..within reason. Having the SAI (steering axis inclination) and included angle out by 5 degrees side to side is a concern, possibly bent knuckle. SAI and included angle are used to diagnose bent steering and suspension parts by alignment techs such as myself. Hope you get it figured out buddy.

SteveMongr

Thank You Tree392 for the insights and defining terminology. It's simple and complicated at the same time.

sicma99ot

Wow lots of great information. Ill set the caster higher and have them check it. I didnt even notice how far apart the sai are. Thats something ill definitely have to look into.