The other day i performed an alignment on my car. Everything was going just fine until i went to adjust my caster angle. The caster adjustment (located on the rear LCA mount) was loosened and i turned as much as i could, but i could not get the number to change at all. As of now the angle on both sides is at 1.3 degrees, way below the factory specs of 3.05. I admit that im not too expierienced at alignments, but even the other techs that were there did not know why. Anyway of fixing this problem?

 

Most alignment machines dont give you a "live" caster reading. Typically you have to adjust it, and then perform another caster sweep to get the corrected angles. Are you use that the ecentrics are moving the control arm, and not just spinning in place?

 

correct, caster is something that needs to be adjusted - if a live reading is given by the alignment machine, then it is just a guess, it needs to then be re-measured... prior to aligning the car, did you check all the bushings and make sure they are tight... many times, that rear bushing gets worn so badly that it clunks around and is loose...

 

The caster readings are live i've performed alignments on several other cars and the caster readings changed as the car was adjusted. I also checked the alignment the next day just to be sure if it changed and the numbers remained the same. I didn't notice any play in the bushings nor any clunking noises, but the car does have a lot of miles so it may be the cause. Ill check later to see if it might be the problem.

If it isnt the bushings is there some sort of aftermarket product that could raise the caster up a bit?

 

Although the caster readings change as you are adjusting them, they are not an accurate reading until you do a caster sweep again... They are a best guess from the alignment machine to help you adjust, but you won't get the true number until the sweep is done again... Remember, the way the alignment machine measures caster is by turning the wheel, it then measures how much the tire lays over at certain toe angles to get caster...

Our cars have a ton of camber/ caster adjustment in the front... Something is definitely wrong if turning the eccentric on the rear lower control arm does not change caster and/or camber...

 

checked the bushings, they look like they are in fair condition and there wasnt any play in the bushings. When i get back to school on monday ill run it quickly on the alignment machine to see if they have changed.

Whats weird is that i did change the position of the cams before and got no change in steering feel nor a change in the numbers when i took the car in the next day to re-check the alignment. Also i clearly remember that the machine that i used had live caster readings meaning that as i adjusted the caster (on a different car) the numbers did move around with the adjustments. What kind of machine do you use your alignments mitsuguy? Im current use the Hunter machines at my school...

 

Yes, the numbers will move, but they are for assisting you in adjustments... you will not get a true caster reading until you do another caster sweep...

we use Hunter machines, I've used three different Hunter machines, from the old school wired heads, to wireless heads, to the laser alignment as well... they all do the same thing... they show you new caster readings, but they are not accurate until you do a caster sweep...