The Stovebolt Site Forums The Shop Area General Truck Talk Checking Caster on a '72 IFS

Bill this is a '72 Independent Front Suspension. I'm not sure where on the spindle I'd put the angle finder. If there is a surface that is parallel to the ball joints I'd sure like to know what it is.

My immediate goal is to make sure I mount it close enough to correct caster that it will easily adjust to the correct spec when I'm finished and take it to a shop to have done right.

Since posting the question I've been looking at it trying to find a way to put something between the ball joints that I could measure the angle on.

I now have some crazy ideas for making a tool, but since I'm good a over complicating things I'm hopeful someone will say hey this surface or that surface is the right one...

I had not stopped to figure out how caster is set on one of these until this afternoon. Its literally by putting more shims under one end of the upper a-arm pivot shaft than the other end.

Right now I'm picturing two l-brackets, each with the correct size hole to fit over a ball joint nut, and both mounted to a flat surface in such a way that the centers of the ball joint holes remain in alignment, and such that a line drawn on the flat surface remains perpendicular to the line drawn through the centers of the ball joint holes.

A pointer of some sort, with a pivot located where the perpendicular line intersects the ball joint hole centers line would be adjusted until it is parallel to the floor. Degrees between the pointer and the perpendicular line would represent my caster measurement. Degrees below would be positive caster.

My flat surface is perpendicular to the floor and perpendicular to the axle centerline.

I have no idea if this description makes sense to anyone but me, but it helped me to write it out. Aside from the precision required in making this thing, the lower ball joint hole needs to be 5/8ths or 11/16ths diameter and I'm not sure I have a drill bit large enough.