Caster Mod for pre 73

[SCOTI]

Originally Posted by itsnotbroken

Hi guys,

"cab4word" asked if I'm sure I moved the contraol arms forward. Yes, I moved them forward. But I double checked the new hole & it's .825" to the rear, NOT .750" as I planned. It is a mistake, but .075" is not enough to make this large caster error.

"theastronaut" - The arms are on the same side they have been on for the last 35 years, BUT, that doesnt mean I put them back on the right side when I repainted them for this project.

That 22 degrees I had yesterday is not accurate. I was just sticking a level on the spindle to get a rough idea. The lower ball joint boss is a lot thicker so it really affects the angle.

I made up a shim for the top ball joint boss so that the digital level sits exactly the same distance from the CENTER of the ball joint shafts. The correct caster angle is 15.5 Degrees (through the center of the ball joint shafts)

Also, the truck was not perfectly leveled yet. The rear was a lot lower than the front. As of today the truck frame is dead level sitting on 6 jackstands & a bunch of shims.

I also read a few other racing forums & checked the caster using the "turn the wheels 20 degrees both directions then do some math" method. These measurements were within .5 degree of the digital level on the ball joints. Close enough to know I'm semi accurate. Close enough to rough this in.

But 15 degrees caster is still about twice what I'm looking for.

I'm going to put the lower shaft back in the original hole & see where the caster was before I started. (why didnt I measure before I started?)

Post a pic/pics of the a-arms. Images help sort things out.

[theastronaut]

This is the correct orientation.

[itsnotbroken]

I put the uppers back on the wrong side after I painted.

This is hilarious.

[cwcarpenter98]

Originally Posted by itsnotbroken

I put the uppers back on the wrong side after I painted.

This is hilarious.

You're not alone on that boat. The previous owner of my truck put the arms back on wrong after replacing ball joints. I didn't realize they were on the wrong side until I did the caster mod as well