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Modify stock A arms for caster

RJ Squirrel

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Well I do love the *** end high with fat tires look, even though doing this robbed me of most of my caster. I have offset bushings installed, but still I can only get one degree. I did the smaller diameter bolts trick on my Polara and it worked, but just seems like a hoaky way to do it.
So now I am considering modifying the A arms by cutting off the rear bushing sockets and welding them back on a little shorter. How much shorter? I was hoping somebody might have done something similar. I would just draw an outline of the arm first, then cut it, lay it on the outline with the ball joint moved back about 3/16 to 1/4 or so?
I know I could just buy the right aftermarket A arms made for this but hey I am a dirt poor cheap *** country boy with a welder.
So any good intel out there?

*** high.jpg
 
I had a thread about this very thing at FABO a few months back.

The man wants MORE caster. How about this idea?

Some states that have annual vehicle inspections frown upon welded suspension or steering components.
I still think that this modification can be successful. I considered the idea of taking 1/4" out of the rear section and adding 1/4" to the front.
If you have some spare parts and time to kill, you might be able to make it work. The integrity of your welds will determine the durability.
Aftermarket UCAs are $450 and up. This mod would cost next to nothing.
I was able to get 6 degrees of caster with stock UCAs and offset bushings in Jigsaw so I saw no need for surgery. I got these numbers from a 72 Duster with stock UCAs and offset bushings:

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Yeah, 3/4 degree negative camber and 5 1/2 degrees positive caster.
There could be a couple of reasons why you have such little caster. I got 4 degrees with stock UCAs and stock bushings so you have something weird going on. Your strut rod bushings could be too thick. Your UCA bushings could be in wrong. You may have the ride height too high.
Just so you know, these cars gain caster as you lower them. The taller they sit, the less caster you will have.
See this chart below. It shows the numbers recorded on an A body front disc knuckle but the other knuckles are not that much different. The chart shows how caster is great at "dive" and terrible at rise. The A body setup has almost 5 degrees positive caster at 2 1/4" below stock and 3.3 degrees negative at 2 1/4" above stock height.


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Look up Junkerup on Youtube. He has some good videos on making your Mopar drive great. Ahh screw it i'll link them.



 
Thanks for the tips guys, I believe my aftermarket knuckles for the disc conversion along with the obvious rake, and the fact the car was beat all to hell and had a bent frame rail, LCA, and strut rod is why I have the caster problem. I am going to fab up a jig to hold the bushings in place, calculate how much I have to move the ball joint to get 6 degrees, cut the arms to necessitate hitting the sweet spot, and weld them back up with doubler plates.
 
Look up Junkerup on Youtube. He has some good videos on making your Mopar drive great. Ahh screw it i'll link them.




Watching that vid right now- better than Dr Phil
I like that dropping the lower ball joint idea, makes sense.
 
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Oh boy there is something very wrong here. My degree of caster is actually a degree negative. With A arms adjusted for full positive caster it is still in the negative. Took the driver side arm out, the offset bushings are in right, and the arms appear to be correct. The car had some shoddy 70's used car lot work done after one of its benders, so who knows. I know the K frame is not a 69, the sway bar runs through it, I thought it was from a 70, but maybe it is a newer year or not even a B body? Guess I should find some part numbers.
Well anyhoo I know why it drives like **** no matter how much I try to align it.
EDIT Found the date stamp 1340- May 1970. Should still work.
 
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Plumb line for reference, the car is on the lift at approx the right rake angle.
The ball joint would need to be moved rearward 1 1/4" to give me 5 degrees positive caster. It is at full droop in this picture, the sway bar links are off and I had the arms at ride height position when I took the measurement.
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Here is the Ebay link to those drop brackets. I think Chris needs to edit his listing.. lol It says 3500.00 But the price is 350.00 for the set including the hardware.

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