caster adjustment

[Cb7_Qc]

hey guys, just coming out of alignment and i have a little problem of wich i am aware since last year but never took time to get into it...although now i'd like to fix it

the caster on my car is off a little bit too much on the passenger side, the wheel is pulled back and its out of specs...car isnt pulling at all tho...

i kept my alignment sheets since a couple years back because i like to try different set ups now and then and took a look at them all the way back to 4 years, and back then the caster was perfect, i never got into an accident either...
the caster changed when i installed my h22 2 years ago and i know we removed the crossmember during the process
now i'd like to know if there is some kind of adjustment on the crossmember itself (besides radius rods) maybe we reinstalled it a bit crooked (thinking here that the holes to bolt it up may be slutted a bit from factory or something)? if not is there anyway to loosen up something like the subframe perhaps and use a pry bar to straighten my caster?
has anyone ever got this issue?

and last, in the eventuallity that nothing can be adjusted and i really do have something bent in the suspension, does anyone have the plans to measure my chassis from under the car? i cant find them from my job (im a bodyman btw) all i could find in the program was top view plans... because worst case, ill just put the dozer on the car and pull it a bit but to do that i need the plans

[Nyne521]

caster is a non adjustable angle it is only a measurement of how far forward or back your wheel is in the well.

if your caster is off that means either it was produced that way as a flaw or someone hit too many curbs or was in a accident.

[Quashish]

when I asked the guy doing my alignment about it he said it didn't matter.

[Nyne521]

when I asked the guy doing my alignment about it he said it didn't matter.

it does matter caster can cause a car to pull what he should of said is it doesn't matter to him cause there is nothing he can do to change it

edit* short of pulling the frame with a come along that is anyway... some cars come with caster imperfections and there is just nothing to change it while in performance cars they have negative caster on purpose to increase stability, reduce torque steer, and help the wheel return to center when cornering

[accordztech]

OH hell yes it does matter. He just doesn't want to adjust it.

Like someone said, something is bent or something is worn. The tension rods have an adjustability, but only by adding washers. Perhaps the rubber there is gone.

Caster is important in high speed hard braking, which way may the car steer....big accident. OR return to center after a turn may not be as great.

[Cb7_Qc]

nah never had an accident since i have the car (5 years +-) and like i said i checked my alignment sheets and all was fine till the year i put my h22... maybe the readings back then wer wrong...i dunno..

i think ill download mitchell on demand and find the frame plans, raise the car and measure everything, this will tell me if i have a bent suspension part....the car is on coilovers and very stiff and i did hit a couple hard potholes so maybe i bent something i dunno...anyways there is a problem thats for sure and visually i cannot find it

ill post the pictures of the frame plans whenever i have time to get them, i think it will be valuable info for everyone here since they dont seem to be anywhere on the internet

[wildBill83]

Nyne521 couldn't be any further from the truth. Caster is adjustable. The radius arms are what control caster. They can have bad bushings or require a shim.

I'm willing to bet your bushings on the radius arms are shot. Did you ever replace them? If they are factory original then I'll bet that is your problem.

[Quashish]

radius arms sounds like it could be why my left front caster is 1.4* and my right front is 2.6*. my car was in an accident on the left side and I think I remember them saying something about the radius arm being bent. my sub frame was tweaked a little bit too but we pulled it. so I doubt bushings are the main issue in my case. wonder if the bent one can be adjusted into spec or if I would have to replace it. my car feels really solid on corners and the steering always goes back to straight.

don't mean to thread jack. just sharing

[Nyne521]

Nyne521 couldn't be any further from the truth. Caster is adjustable. The radius arms are what control caster. They can have bad bushings or require a shim.

I'm willing to bet your bushings on the radius arms are shot. Did you ever replace them? If they are factory original then I'll bet that is your problem.

any shop you take a car to for just a regular front end alignment, I can guarantee they wont touch the caster.

whether proper or not that's the way it is. No shop is going to replace the bushings on the radius arm or shim them for an alignment. Most of the alignment machines they use won't tell them how so it doesn't get done.

[deevergote]

Most alignment jobs only deal with toe.

[Nyne521]

thrust angle, toe and camber if the adjustment is available is what i do for a basic alignment at work

[Cb7_Qc]

Nyne521 couldn't be any further from the truth. Caster is adjustable. The radius arms are what control caster. They can have bad bushings or require a shim.

I'm willing to bet your bushings on the radius arms are shot. Did you ever replace them? If they are factory original then I'll bet that is your problem.

i have a full bushing kit from energy suspension installed, they are 2 yrs old and still look new, i know the radius rods can affect the caster, this is why i asked in my first post if caster could be ajusted somehow ''besides radius rods'' because i know those bushings are not the problem, although yes one rod could be bent, but i cannot see it with bare eyes...
as for what type of alignment i get, its a very complete one since i have camber kit on all 4 wheels and i get it aligned by a co-worker at the bmw dealer i work, we play on all possibles adjustments and like i said i try something a bit different every year depending on how the car feels, this year i had to do alot of highway so we added toe in to make it more stable in straight line and since i want my tires to last at least another year, we straighten up the camber a bit, last year i wasnt doing as much so we set it to be more nervous in the curves, camber waa alot more negative too

[wildBill83]

Nyne521, my comment is about this bunch of WRONG info you gave to the op.

caster is a non adjustable angle it is only a measurement of how far forward or back your wheel is in the well.

if your caster is off that means either it was produced that way as a flaw or someone hit too many curbs or was in a accident.

That entire post is wrong, cars don't leave the factory with flaws in the suspension. That is just dumb, what kind of law suit would that invite? Caster can be from bent lower control arms, bent radius rods, or worn bushings and possibly front crossmember damages. You can fix it by replacing components that don't measure to spec, not by altering the frame to match bent components.

it does matter caster can cause a car to pull what he should of said is it doesn't matter to him cause there is nothing he can do to change it

edit* short of pulling the frame with a come along that is anyway... some cars come with caster imperfections and there is just nothing to change it while in performance cars they have negative caster on purpose to increase stability, reduce torque steer, and help the wheel return to center when cornering

Again, you don't pull the frame to fix caster. Thank Dog I don't go to your shop, who knows what else you bend rather than approach a repair correctly.

any shop you take a car to for just a regular front end alignment, I can guarantee they wont touch the caster.

whether proper or not that's the way it is. No shop is going to replace the bushings on the radius arm or shim them for an alignment. Most of the alignment machines they use won't tell them how so it doesn't get done.

Then I go to a good shop for my alignments then. They inspect the entire system and will not align a car with any visibly damaged components, they will replace the bushings for a cost and then align the car. I replace my own worn bushings though. They also told me my SE was out of spec on the caster, camber and toe, which I expected because everything in my wheel wells were new except the radius arms. They adjusted it all back into spec except for caster. I replaced my LCAs with new ones and went back for the alignment and it fixed my caster problem.

Most alignment jobs only deal with toe.

My local shop only deals with toe too unless they are working on a car that they know is going to be used for more than a grocery getter. What they adjust for your average Geo Prism owner isn't what they would pay attention to on a Corvette Z06. I requested specific adjustments on my vehicle and they complied without batting an eye or raising my price.

radius arms sounds like it could be why my left front caster is 1.4* and my right front is 2.6*. my car was in an accident on the left side and I think I remember them saying something about the radius arm being bent. my sub frame was tweaked a little bit too but we pulled it. so I doubt bushings are the main issue in my case. wonder if the bent one can be adjusted into spec or if I would have to replace it. my car feels really solid on corners and the steering always goes back to straight.

don't mean to thread jack. just sharing

Radius arms and LCAs as a pair are most likely bent in your case.

i have a full bushing kit from energy suspension installed, they are 2 yrs old and still look new, i know the radius rods can affect the caster, this is why i asked in my first post if caster could be ajusted somehow ''besides radius rods'' because i know those bushings are not the problem, although yes one rod could be bent, but i cannot see it with bare eyes...
as for what type of alignment i get, its a very complete one since i have camber kit on all 4 wheels and i get it aligned by a co-worker at the bmw dealer i work, we play on all possibles adjustments and like i said i try something a bit different every year depending on how the car feels, this year i had to do alot of highway so we added toe in to make it more stable in straight line and since i want my tires to last at least another year, we straighten up the camber a bit, last year i wasnt doing as much so we set it to be more nervous in the curves, camber waa alot more negative too

I would buy a new set of LCAs and compare them to the shape of the existing LCAs, I have a couple of pairs that bend 1/4"-3/4" back from where they should be. Hitting pot holes can bent the LCAs easily on a lowered car with poly bushings.

[Nyne521]

if the car was in an accident and the frame is bent that can mess up your caster, and the only way that will be fixed is to try and straighten the frame or to get another car...

and if you ever buy a car with perfect alignment let me know

and as you mentioned yourself they told you your caster was out of spec but did not adjust it. You replaced parts to fix the problem and brought it back and the caster was corrected.

the parts don't need to be visibly bent to put the car out of spec. SOOO in his case they may not be, and they will still align his car. Caster will be off and no one at the shop is going "adjust caster" by blindly replacing parts that may not be the cause, unless asked to.

[andrew22888]

If you have adjustable upper ball joints like the ones you just turn around to make it adjust camber. Then you can actually adjust those forward and backwards for caster. So maybe one of yours got turned.