I have done everything that I can think of and cannot get the alignment on my 70 Duster to stick. We set the ride height to where I want it, do the alignment and then take it around the block -- when we get back to the shop, its come undone -- its either sitting too high now, or too low, or one tire is leaning in too far or out too far, it just wont stick!

I was told my lower control arms were shot and torsion bars were kind of weak, i replaced them and still nothing, alignment will not stick! Everything on the front end is brand new. So what's left? Maybe a tweaked frame? I'm out of ideas!!!!

I'm grasping at straws here but the lower control arm bushing bolts should not be tightened until the car is on the ground and resting at ride height.

I had a 70 Duster years back that was kinda doing the same thing and it ended with a crack in the k member where the lower control arm bush is pressed, maybe jack it up on the lower control arms where the ball joint is and grab the wheel and try to move it top to bottom.

Mitch

Even if the frame was bent. I'd expect your settings to stay from before and after a test drive.

The pads on the alignment rack must be free. This was allow the suspension to settle after every adjustment.

I know a tech who spent almost an hour just to set the toe. Turned out to be the pads still had the pins to hold them still in them.
Once they were free, it was a couple minutes.

my 1st thought was that the UCA cam/bolts werent being tightened enough but there was a(similar) thread way back & iirc something was loose in the LCA or was bending & he was pulling his hair out until he caught it.

hi try backing t.bar ajusters with support under frame then ck for play at lower control arm pivot at k frame

someone with a Dart in my club had the same issue with her k-frame, turned out she had a crack in it and that kept her alignment from happening . . . i'll try doing everything you guys suggested!

I had a '70 Swinger do the same thing. The mount for the right side LCA was broken out of the K-frame. Pretty common on A bodies.

To re-iterate [in part] what others have already said:

1. If the problem were simply inexplicable height changes, I would recommend revisiting at what height the UCA and LCA bushings were tightened (they are supposed to be left a bit loose, then tightened at normal ride height). Also, to inspect closely the REAR anchor points of the t-bars, which need to be solid and immovable in their mounts.

2. Since the problem also involves a noticeable shift in camber (which is how I interpret your description of the tire "leaning"), you need to look for something in a suspension component or attachment point that is supposed to be solid and immovable, but isn't. Something simply bent, but not shifting isn't going to cause this. Inspect carefully the point where the LCA pivot meets the K member - are there any cracks, or is the welded tube in any way loose? What about the condition of the LCA bushing itself? Continue out the LCA to the lower ball joint, looking for anything cracked, or loose. Do the same inspections on the upper ball joint and in along the UCA. Look closely at the point where the UCA eccentric bolts are. Are the bolts tight, the bushings intact, and inner fender and related structure solid and uncracked?

A thorough and careful inspection is in order. That being said, my money is on the structure at or near where the LCA pivot shaft is anchored.

gotta be something broken, loose or too tight or a combo of each.

Well we got the Duster back on the lift and noticed from the rear that the drivers side leaf spring is twisted. From the axle back to the rear hanger the leaf spring is twisted to the left, looks like the bushings are shot and so the hanger isn't in properly. My guess is this is helping cause the alignment to not stay in place, I mean, if the backend isn't right how can the front be right?

my a body had the tube cracked and loose that houses the lower a arm bushing bolt,in the k-member and the car drove really bad,lol.

Well i'll check that this weekend, the tube thats located in the k-frame that the lower control arm stud goes through. Does someone repop these tubes?

Do a 4wl alignment. Dont do a thrust angle. Put all four heads on so you can actually see were the rear is setting. It will show the axle positioning if your machine was built after 2000.