Caster way off

I have a 4.5 inch RC lift on my 1998 XJ (adjustable upper and lower control arms). After the lift I had an alignment shop do an alignment. Last week I installed some control arm drop brackets, also from RC. When I was installing the brackets I realized there where no shims behind my lower control arm. I made sure the arms were to what the directions said. When I got the brackets on I had a shop do the alignment. My caster is at -2.9 degrees. I think spec is 5-8 degrees. The guy at the shop said adding shims could note make up this difference to get my caster to spec. He said I need to lengthen the lower arms and shorten the upper arms. Any idea how much longer I should make the lower and how much shorter I should make the uppers so I can get close enough for shims to get me to spec?

Contact RC to see if they can recommend some control arm lengths. With the drop brackets they might not have standard measurements.

Most would say that a lifted XJ Cherokee is not aligned to the stock Cherokee specifications. Typically pinion angle is more important caster angle. You will need to find a useable compromise between the two that give enough caster for good steering, and enough pinion angle for no vibrations. If you have adjustable control arms, why would you need shims ?

Here is chart that is often posted. It will get you close.

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The time to have done the adjustment was when it was on the rack.Guy knew what was needed ,why didn,t he do it.
You may have had to pay for the extra labor time in addition to the standard alignment,,,,, but you get to pay again for him to do the job again......

If you have adjustable arms why are you worried about shims for? Just tell the tech to align it and quit being lazy

I set the control arms to the length RC had in the directions for the drop brackets.

I called another Firestone who said they would adjust the control arms for 75 a side. Luckily I already bought the lifetime alignment through them so the rest of the work will be free.

Thanks for the help.

If you can install control arm drop brackets, why would need a shop to adjust your adjustable control arms ? Simply shorten each lower the same amount, and you are done. I have had 3 different size lifts on my XJ over the 14 years and 100,000+ miles I have owned it, and it has never been to an alignment shop. Should it ever need to go, I would never take it to a tire store that has an alignment rack, I would go to a Frame Alignment and Suspension shop and have real pro look at it.

If you have adjustable arms, tell the shop to center the bump stops in the coil.
That's the best way to get it going straight.
Pinion angle will have to suffer, unless you cut and turn it.
Can you post a picture of the coils w/ the vehicle at ride height?. Take the picture standing in front of the coil perpendicular of the driver or passenger side.
I'm curious to see what it looks like.