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Each upper control arm is connected to the body with a bracket using 4 bolts. Between the body and the bracket is where the shims are. The more shims the more the upper A arm is away from the body causing the angle of the suspension to change. This is camber. In the front there will be a different amount of shims in the front and rear brackets. This difference is to set the caster. Caster is only for the front because it only effects the turning geometry.
Go under the truck and Get the truck on a Alignment machine and get a printout. Figure out what shims need to be changed.
There are thick shims and thin shims. I found that the thick shims affected the camber about .2 degrees each. The thick shims according to the book will affect the caster .6 degrees, the thin .3 degrees. When setting the camber you will always add or subtract the same shims from both the brackets on the same wheel.
How do you do this? Take off the tire and wheel. Jack up the truck by the frame. ALWAYS Use jack stands for safety, you don't want the truck to fall on you, this will hurt. Take another jack and jack the lower A arm up too take the weight off of it. Remove the horizontal bolt or bolts that connect the upper A arm to the brackets. When you take this bolt out of the front it helps to grind the bolt end into a blunt point to help in reassemble. According to the book this bolt gets torqued to 260 ft/lbs..
You will then see 4 bolts holding the bracket on to the frame. This is the hard part. Loosen the bolts. It's hard getting behind the bracket to keep the bolts from spinning. Once the bracket is loose slip in or out the needed shims and reassemble. Tighten the bracket bolts to 60 ft/lbs.
Put the truck back on a alignment machine and check it out. You may have to do further adjustments. Then set the toe.
Each wheel will take you about an hour with two people working. One holding the wrench behind the brackets to keep the bolts from spinning and another turning. I did a rear wheel myself last week in about 2 hours using an air wrench.
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