Problem with caster, need to find a real alingment shop

R

r0b0t c0rpse

New member
I've had the car aligned a few times, no one got it right. Unfortunately, the cast is out, too positive on the drivers side and it makes the car want to push itself to the passenger side. My chassis has no provision for caster or chamber adjustment. I did my good old calibrated eye ball alignment when I installed the current struts/springs/swaybars/trailing arms. I brought it in to a belltire and they charged me 50$ and said I did a good job, giving me a sheet showing they hardly changed anything. Great.

I think to fix the caster, the front sub frame will have to be loosened and tweaked a bit. I can't think of any shop I'd trust to do this, I have visions of my car on an alignment rack with the engine and trans crashed into the pit below it. I've considered trying it myself, by supporting the body on stands or bricks and putting a big floor jack on either side of the sub frame, then trying to push one side and pull the other after loosening it, until the cross measurements are equal... I am going to install adjustable coil overs and may install tubular lower control arms, so I'd need a decent alignment anyway, so I figured I'd see if there is any place that any one has had do something like this before. Maybe I'd have them install new sub-frame bushings while they're in there.

Readers digest:
GM sucks at chassis adjustment, need to find a shop that can tweak the position of the sub frame to correct it.

FYI the car is a '99 buick regal with a fairly tame ~400 hp out of the 3.8 L supercharged / fwd
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Belle Tire on Long Lake and Rochester Rd hooked me up on my Camaro. I'd recommend them in a heartbeat.
 
location?
I know Bakers in pontiac moves the subframes
I usually never even had to jack them up on the rack to get them to move. loosen the subframe and use a prybar or rachet strap
 
are the front control arm bushings "the hockey puck ones" any good ?If they have seperated thats more then likely the issue. if your lucky you might get a .5 degrees out of the subframe. Of more concern is the control arm bushings.
 
^True, but they don't usually affect caster a whole lot, just make noise. These are the front control arm bushings on that car.

1BADAIR said:
location?
I know Bakers in pontiac moves the subframes
I usually never even had to jack them up on the rack to get them to move. loosen the subframe and use a prybar or rachet strap
Click to expand...

X3 on this. But what are the #'s? as stated, you may get .5 deg caster from a subframe adjustment (which most shops charge extra for), but you can have the frame pulled by a body shop and get a lot more. If the caster is out, you likely have a bent part, or bent frame. As an alternative, you can sometimes compensate with camber, but that would require enlarging the strut-to-knuckle mounting holes and adjusting accordingly.
One last thing, I have found that a tire is often the cause of a pull or drift, and crossing the front tires will ofte solve the problem or make it pull the other way. As well you should know that no car will drive straight on every road because of road crown.
 
Who told you that ? LOL. If the bushing are beat out of it really bad the caster will go from static to dynamic and the car will steer all over the place.

Ponyryd said:
^True, but they don't usually affect caster a whole lot, just make noise. These are the front control arm bushings on that car.



X3 on this. But what are the #'s? as stated, you may get .5 deg caster from a subframe adjustment (which most shops charge extra for), but you can have the frame pulled by a body shop and get a lot more. If the caster is out, you likely have a bent part, or bent frame. As an alternative, you can sometimes compensate with camber, but that would require enlarging the strut-to-knuckle mounting holes and adjusting accordingly.
One last thing, I have found that a tire is often the cause of a pull or drift, and crossing the front tires will ofte solve the problem or make it pull the other way. As well you should know that no car will drive straight on every road because of road crown.
Click to expand...
 
Sean said:
Who told you that ? LOL. If the bushing are beat out of it really bad the caster will go from static to dynamic and the car will steer all over the place.
Click to expand...

Nobody told me that-I know it from personal experience. As well, my post says they don't usually affect caster a whole lot, meaning exactly that-it's rare for them to be so bad that they affect the caster. Any I have seen are usually torn or have come out of the shell, that usually just makes them hit the top or bottom of the subframe, but they don't come right out and bang around-they are still in the shell, but not fully. Yes, they CAN come out completely but there would be TONS of noise and very poor handling, which an alignment shop or anyone with any sense whatsoever should notice on a road test.
 
u loosen the sub frame with the car on the ground? and adjust it that way? i think its all in the subframe.

i just want to take as much away from drivers side and add as much to the passenger side to even it out.
 
Why dont you a post a copy of Belle's alignment sheet so we can see what you are talking about and just how bad it is. Did this problem arise when you changed parts or did it just appear one day?
 
Jenga said:
Why dont you a post a copy of Belle's alignment sheet so we can see what you are talking about and just how bad it is. Did this problem arise when you changed parts or did it just appear one day?
Click to expand...

Tooooo long ago. must have been in 2007. Think it was +3 driver and +1 passenger


Anyway... it's been a "feature" of the car for as long as I can remember. Might have had something to do with the sub-frame being out of the car during the original engine swap.
 
By rotating the cradle you may be able to get .5* change on each side, but camber will be effected. Caster on a front wheel drive car is steup differently than a rear wheel drive. Most of the time the right side caster on a RWD is set higher on the right to compensate for road crown. If you plan on installing new coilovers, do that first and set your ride height. Then you can take it to a good trustworthy shop and have the alignment set. Make sure all the front end parts are good, like ball joints, tie-rods, control arm bushings, and even the cradle bushings. I myself had done hundreds of cradle shifts on many different makes of cars do get the alignment as close to perfect as I could. GM products always yeilded more adjustment then Ford or Chrysler.
 
I think i'll have them replace the subframe bushings... if possible, I'm not sure if they'll need to press them out or what, if so, I wont.. I don't really want them pulling the sub frame out, because if i'm going to have some shop do that i might as well go get an aluminum one and an aluminum oil pan to throw on.

Any way, i'm going to install tubular LCA's and see what they can do.
I think the sub-frame is tweaked from the original engine swap.
 
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