I’m rebuilding the front end of my 72 cutlass convertible - I’ve read many great threads on here - I want to ask everyone’s opinion - since I’m redoing all the bushings / ball joints / etc - should I replace the UCA shaft with the off set one so I can add more caster? Your thoughts are appreciated - thanks! ~ Joe R.

 

i thought the offset shaft was to compensate for frame sag and add in addtional camber so you could use less shims?

I redid mine w all new bushings, ball joints, bearings and the original shafts and the align ment guy was able to get more than +2 caster w no issues. YMMV

 

Thanks - I didn’t order it when I got my toys from rock auto - but I just wanted to make sure I wasn’t screwing up by NOT doing it.

 

The problem with the offset shaft is that the offset is constant across the length. To increase caster, you need to shim the rear outboard a lot, but not the front. These offset shafts don't fix that problem, so you are still limited to about 2-3 degrees by the length of the bolts that hold the shaft to the frame. The offset shaft CAN help if you have tall ball joints or spindles, but then you have the problem that the inboard end of the upper control arm will hit the manifolds or headers, especially on the wider BBO. The right way to increase caster is to either get aftermarket arms with the ball joint relocated rearward or relocate the holes in the frame mounting tabs where the shafts bolt up.

 

Thanks Joe - sticking with the stock control arms and Shafts.