caster, camber, and toe-in

Dan,
Here's a chart from my 70 Chassis manual. Kind of hard to read. Caster preferred setting is -1/2* (+ or - 1/2*), 0-1* range, 1* side to side variation permitted. Camber preferred setting is +1/2* (+ or - 1/2*), +1*-0* range, 1* variation side to side permitted. Toe in 3/16" (+ or - 1/16") preferred, range 1/8"-1/4". A more performance alignment would have 3-3 1/2* + caster, -1/2* camber, and 1/16" toe in. With the stock A body front suspension, as the suspension travel goes from full extension to full compression, the camber goes positive. The outside tire in a turn (where suspension would be compressed) would have + camber, and the tire tends to roll onto the sidewall, and slip. The opposite happens to the inside tire. This is why our cars understeer moderately when pushed hard into a turn. Big swaybars minimize this effect. Dialing in - camber also helps in this regard. The more positive caster you run, the better the car will track at speed. Positive caster also induces a camber change as the wheels go from straight to full lock. The outide tire in a turn would have increasing - camber as you turn the steering. Mercedes Benz uses like 10* positive caster. If you have ever seen a Benz parked with it's wheels at full lock, you can actually see one tire tilted out at the top, and the other tilted in. Mercedes Benz are some of the best handling cars in the world. Anyway, maybe more info than you needed :laugh:

 

Dan,
Actually it's very easy. If you don't have a Buick chassis manual, you should get one. Explains everything very well. According to the manual, to make camber more -, add an equal shim amount to both bolts. By adding a pack of shims .090" to each bolt, camber will be reduced by 1/2*. To make caster more positive, remove a shim amount from the front bolt, and add an equal amount of shims to the rear bolt. If you remove .030" from the front bolt, and add it to the rear bolt, caster will increase(more +) by 1/2*. If you set up your camber first, you can change the caster(without affecting your camber)

 

Yes, but too much caster and you will get tire scrub on tight turns. My recommendation is to just adjust it to factory specs. Be sure to notice the "SAI" (steering axis inclination) and "included angle" readings on both sides. That will let the alignment tech know of any front end parts are bent. Also have him check the "TOOT". Toe out on turns. That will check to make sure that both steering arms on the spindles arent bent at all. Some alignment techs dont understand or care about these readings.

Jason