YJ DIY Caster measurement


New Member
Jan 2, 2023
Lake Ozark, MO
Hey all, I just completed an S10 batard pack lift on my 90 YJ with a 1” shackle lift. I am trying to measure the caster so I can order the correct shims. Here is my diy method and results…. I used my iphone taped to a straight edge with the compass app on. Set the front wheels to match the rear degrees. Turned the wheels 20 degree in one direction. Put a magnetic digital angle finder on the bottom of the knuckle and zerod it. Turned the wheels 40deg the other direction and took the reading off the angle finder. The results where .14 on the drivers side and .08 on the passenger side. I believe I am supposed to multiply each number by 1.5 to calculate caster. If I do that I get .21 deg on the DS and .12 deg on the PS. There are the factory shims which I believe 2 deg installed currently . To reach the spec range of 3-7 deg does that mean I need 6 deg shims?? TIA!