WFO Concepts Axle Shim, 3" Wide, Steel
These steel shims are designed to change the pinion or caster angle on a leaf sprung vehicle. These shims are 3” wide, and work with 3” wide leaf spring packs. They are CNC machined from mild steel, Silver Zinc Plated and have a 3/8” center pin hole milled and drilled into them. THESE SHIMS ARE DESIGNED TO BOLT INTO YOUR LEAF SPRING PACK!
You will need to clamp your springs, remove the center pin, and bolt the shim into the spring pack! If you are using these shims on a front axle, please read the paragraph below on “Caster Angle”.
Shims are sold individually, NOT in pairs.
Caster Angle: Caster angle is something that is very important on front axle geometry. On a fully off-road vehicle that does not see speeds over 15mph, you can get away with poor caster angle. If you are working on anything else, please read this! Caster Angle is the angle that the knuckles sit at, compared to the ground. If you shim your front pinion up or down, the caster angle with change with the shims. The less caster angle you have, the more the vehicle will dart around on the highway. The more caster you have, the straighter the vehicle will drive. A drag race car will tend to have up to 18 degrees of caster. The first thing that everybody does when they lift their 4x4, is install shims to point the differential up at the transfer case. Even though this does fix some driveline angle issues, it usually does more damage with the steering geometry than it is worth. On a Dana 44, we suggest 5 degrees of caster angle. On a Dana 60, we suggest 3 degrees of caster angle. This means that the knuckles will be leaning back at the above angles. It you had high-steer arms on the knuckles, the arms would be pointing up at the front bumper at 5 degrees. Even on a fully off-road buggy, at no point should you ever go past 0 degrees and point the knuckles down at the ground in front! If you need to make your driveline work at a steep angle, check the u-joint or yoke sections for high angle u-joints and high angle yokes.