How do you adjust caster?

[ChallengerHK]

Went out for a highway speed, post-suspension upgrade test right today. Wheel has practically no centering, which I'm assuming means that I need to add caster. How? Hope I'm not being too dense. I get the adjustments for camber, toe and ride height, but I'm not seeing anything obvious that would let me affect caster.

[GoodysGotaCuda]

caster and camber are both adjusted by the upper control arm cam bolts. You adjust one, the other moves as well, so really you would have to get a bubble gauge and do it, or have a shop adjust it properly.

[ChallengerHK]

Thanks, Goody.

[ntstlgl1970]

Essentially you would adjust one (front or rear) eccentric one way and turn the other eccentric the opposite way but same amount to change the caster. Unfortunately you have to set caster before camber or toe as it can change all the other angles. Here is a pic and some background info...

Caster is the forward or rearward tilt of the steering knuckle in reference to the position of the upper and lower ball joints. Caster is measured in degrees of angle relative to a true vertical center line. This line is viewed from the side of the tire and wheel assembly.


Forward tilt (upper ball joint ahead of lower) results in a negative caster angle.
Rearward tilt (upper ball joint trailing lower) results in a positive caster angle. Although caster does not affect tire wear, a caster imbalance between the two front wheels may cause the vehicle to lead to the side with the least positive caster.

[ChallengerHK]

I do have a very slight pull to the right, but I'm way more concerned about the wandering. Unfortunately, I'm pretty sure (like dead certain) that the UCA bushings are worn out. I had planned to install tubular UCAs which would take care of the bushings and the ball joint, but that's on hold for the moment. On the other hand, I hate to have an alignment done now with some worn out parts. I'm going to need to think on this one for a while.

[ntstlgl1970]

Unless you know the alignment guy, most places won't align a car with worn out parts. And since you don't know where the angles are at now, it would be a shot in the dark to suggest changes to correct for the pull since there is no way to know if it is caused by cross caster or cross camber.

Know anyone at a local school with an alignment rack or a community college auto program near you? When I was in school, the auto program didn't charge labor for working on cars if there were relevant to the course work. There are always alignment classes running. Aligning cars with the eccentric adjusters are a piece of cake .

[ChallengerHK]

I have a regular shop I was using before I got a garage that will pretty much do whatever I ask, so I'm sure I could get it done. I just hate to waste the money.

After a couple of hours of internal debate I'm going to leave it for the moment and let all my driving with it be tooling around town. As I said to someone else recently, hopefully in the next couple of months I'll land a job and the money issue will be solved.

[Bullitt-]

HK, if you've got the time an at home alignment can be done to get things at least close.
http://www.veloandy.com/pics/alignment/how_to_align_your_car_at_home.htm

  Controll arm bushings are not hard to install, upper & lowers $40 http://store.summitracing.com/partdetail.asp?autofilter=1&part=ENS%2D5%2D3112G&N=700+4294908110+4294908104+4294925074+4294925130+400008+115&autoview=sku
Haven't driven the car yet but getting adjustments close was not difficult, it took about 4 hours to create the devices, calculate measurements & adjust the components.
 

RE: UCA bushings the rear was rotated max inboard with the front rotated max outboard to gain max positive caster, this pulls the upper ball joint as far back as it will go. Measured my caster using a square device placed on the floor & finding the relative difference to the upper & lower ball joint grease fittings. If my measurements are correct I have 2.08degrees positive caster, even if I'm off by 20% its in spec for a power steering car.

I used the complete Energy Suspension kit, includes just about everything, sans sway bar bushings, for the front & rear $120 http://store.summitracing.com/partdetail.asp?autofilter=1&part=ENS%2D5%2D18105G&N=700+115&autoview=sku

Wade

[Moparal]

You can get uppers for about 8 bucks each or less from local parts houses. They very in price. 13 bucks each for upper ball joints. I could loan you my tools, or you could pull the uca's off and ship them to me and I will install them for free if you'd like.  The uppers are super easy to do with the right tools. I have the bj socket also.

[ChallengerHK]

Bullitt - thanks for all the info. I need to digest that and maybe I'll give it a shot. Time is one thing I have in bushels.

Moparal - I don't think I'd have much problem pulling and installing the parts, but yhanks for the offer of tools and/or labor.. I've been going with all Moog parts for the new stuff, so I want to see how much those parts are. There's also the idea that I do eventually want to go with the tubular UCAs, so I don't want to put a load of money into something that I'll just be pulling shortly after regular paychecks are coming in again. I'll check some prices on Moog and see if I think it's worth it.

[Chryco Psycho]

when I adjust a front end I turn the front adjuster bolt all the way out & the rear all the way in , the camber ends up extremely close to perfect doing this assuming the bushings are nto shot , this will max the caster adjustment & the car will drive way better , just reset the toe in & you will be good for a while

[ChallengerHK]

 

I was covering Mopars at the Rock roday, but I'll give that a shot when I get some time, Neil.

[ChallengerHK]

Had a few hours to play today and I worked on the caster. Fronts adjusted all the way out and backs all the way in (as far as I can tell, at least), and I've got a slight pull to the right, but otherwise it's much better.

As I've said several times, I wish I knew about everything that happened to this car in the 30 years I've had it  . Both of the right side bolts were all the way out. The left side front was all the way down and the back was all the way up 

Anyway, no more time today, but I'll give it another shot next week and see if I can twea everything the way it should be. My plan is to pull the right side front back in a little and see what happens. Make sense?

[Bullitt-]

Before you change the upper control arms again measure your toe in.  Set your steering straight & mesure the difference in the front vs the rear of the tire, should be 1/8" narrower at the front, adjust by rotating the tie rod sleeves. Using a trammel gauge would be more accurate but you will get an idea of where your at.  I worked to get my steering wheel straight & both tie rod sections the same length before I set my toe in to preclude issues caused by an imbalance in the power steering.

[Chryco Psycho]

   make sure the toe in is set first , if the toe is correct you may need to add a touch of Camber to the left side by turning the rear bolt out a little