Alignment at home and aftermarket UCAS too.

[ckessel]

Just a little "pop-in" moment here to pass this along:
Sometimes damage can be hiding and you have to dig to find it. The picture below shows a damaged LCA mount in a 73-76 A body K member.

View attachment 1772075

This can happen when a lower control arm bushing fails and the locating pin is allowed to move and rattle around. The impacts of the front wheel don't usually damage the control arm as much as it can the K member. The metal around the LCA mount takes the most of it. The fix?

View attachment 1772077

Clean the area. Measure the distance between the LCA mounts. Compare that number to that of an undamaged K member. Move the "tube" to where it matches the measurements of an undamaged K member. Fill in with weld around the hole, then weld a washer over it all. Make sure the washer is not thicker than the raised lip on the "tube"/LCA mount. If it is thicker, be prepared to dress it with a grinder where the LCA pin will reside. Using a washer too thick will move the LCA slightly rearward, possibly reducing caster by a small amount. I doubt that it would be much though.

View attachment 1772078

It can be hard to know if the end result is thicker than before since you'd be welding all around the LCA mount tube. Maybe you could measure a stock K member or measure the damaged one before doing any work on it. I'd think that anything 1/16" or less would not matter but that is just a guess.
Offset upper control arm bushings or these UCAs would surely make up for a slightly thicker LCA mount.
While you're at it, you might as well weld a washer over the other side to make both sides equally strong...OH, maybe consider welding in some reinforcements to the steering box mounts too?

View attachment 1772082

That happened on my 73 Duster many years ago. I did many reinforcements to the K being used for the 65 like the washer deal plus more.

 

[dvw]

A lot of good info here. A few things not metioned. Caster is directly related to chassis rake. If the car is higher in the rear? The caster goes negative by a 1 to 1 ratio per degree of rake. By using these much higher than designed caster numbers what happens? As previously mentioned as caster gain is positive, the outer tie rod goes down. The lower ball joint, control arm pivot, and inner tie rod are all still in there OE locations. Was the outer tie rod was in it's correct location from the factory? Highly doubtful, but probably close. Now with 5-6 degrees of caster it's location is most likely not in the ballpark. What does that mean? Through out the range of up and down suspension travel the toe is changing. Is it changing too much? It should be checked. Personally I don't see any need for that much caster. My car gets run close to 150 mph on a regular basis and goes straight a string with 2 1/2 degrees caster. Just my 2 cents. Probably have performed over 5000 alignments in my day.
Doug