So it's PS caster that gets adjusted for road crown? 1/2 a degree less than the DS?
FRONT END ALIGNMENT QUESTIONS
- Thread starter CFD244
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You can adjust either side. By adjusting the driver side it will leave you with more positive caster. Seems most prefer the feel of more positive caster. The road crown will pull the car toward the ditch. Caster pulls to the side that is least positive. This can be used to counteract the pull towards the ditch. Some prefer to use camber to counter act the pull toward the ditch. I try to use caster when possible. Caster used in this way doesn't cause tire scrub or wear. Excessive caster split from side to side that causes you to turn the steering wheel From straight ahead to counteract the caster pull will scrub the tires and can cause wear. Hope that makes sense.
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Thank-You for your input.
With the DS having so much more pos camber and only one way to decrease it (front cam moved inward), would it not make sense to get the DS done first, then dial in the PS since the PS appears not to need as much front cam manipulation? (sorry long sentence).
Sure you can do that to see where you end up on the driverside first. You may have to reposition your front offset bushing on the driver side.
grimreaper
Cross Member
Sounds like you are on the right track. 1/2 degree more positive caster on the right side should compensate for road crown.
Geez, don't wish that on me.
Fingers crossed for you.
I always start with the front UCA bolt adjusted OUT toward the fender and the rear adjusted IN toward the engine. From there, I usually leave the rear bolt where it is and adjust the front to get to my numbers.
Never settle for positive camber with radials. You'll sell yourself short on tire wear, handling and control.
The "Skosh" chart is decent and does work well for most people. Note that the only category calling for zero camber is drag racing where you aren't expected to turn the car!
I've seen suggestions from people to make adjustments with a driver in the car. I'd love to see how much of a difference this makes with and without.
Stiffer torsion bars and springs compress less than stock springs.
The alignment does change a LOT during the range of suspension travel, as shown here:
In that chart, it shows how at a standard ride height with zero camber and 1.77 degrees of positive caster, by lowering the car just an inch and a half, you're now at over 5/8" degree of negative camber and you gained almost 2 degrees of caster!
Crazy, huh ?
Never settle for positive camber with radials. You'll sell yourself short on tire wear, handling and control.
The "Skosh" chart is decent and does work well for most people. Note that the only category calling for zero camber is drag racing where you aren't expected to turn the car!
I've seen suggestions from people to make adjustments with a driver in the car. I'd love to see how much of a difference this makes with and without.
Stiffer torsion bars and springs compress less than stock springs.
The alignment does change a LOT during the range of suspension travel, as shown here:
In that chart, it shows how at a standard ride height with zero camber and 1.77 degrees of positive caster, by lowering the car just an inch and a half, you're now at over 5/8" degree of negative camber and you gained almost 2 degrees of caster!
Crazy, huh ?
Hoping I can get rid of the 2* pos camber and still retain decent caster with the front cam only for the driver's side.
The way I read the chart is that zero camber falls near the middle of the spec for the auro cross and max performance street categories.
Well, the best I could get on the DS is 1/8* pos. camber and 1/4* neg. caster.........Now what??
Never even tried the PS yet.
Never even tried the PS yet.
Is there a comparative measurement you can make at the lower ball joint of each side to make sure the lower control arm is square to the frame?
I can do that.
I added a .050 shim between the lower BJ and knuckle. Brought my camber to neg .25* and caster to 0*
Can I add larger shims if the squareness checks out?
EDIT: I measured from lbj grease fitting to a plumb line dropped from a forward frame hole on each side of the car. Left and right measurements are identical.
I added a .125 shim and was able to get .4* neg camber and 1* pos caster. I can take out a little more camber to increase caster with the front adjustment cam.
Any advice?
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Alright, I'm going to apologize. I edited my first response.
Camber can and does change ride height, especially dynamic camber changes like what you can get with large positive caster settings, and that is important. (and I know this!)
My comments were entirely too dramatic, and were based entirely on the setting of a static alignment. My point was that during a static alignment you're rarely ever changing the camber by a large enough amount to make a big enough difference in the ride height that you'd need to go back and reset it, and then end up in some loop of resetting your ride height, resetting your camber, resetting your ride height, resetting your camber and so on. That's not something that should really be a concern the vast majority of the time.
And of course in this thread we have someone trying to change the static camber by 2°, demonstrating it can happen. Personally every time I've roughed in an alignment I've been within a 1/2° of the camber I wanted before I even put a gauge on the car. But clearly there are exceptions.
Oh totally, in my old man's shop we used a couple of teflon sheets with dish soap. It just makes it a bit more difficult to get repeatable caster numbers. Which was less of a concern because the old British cars we were working on have kingpins and not much in the way of adjustment.
Those numbers are terrible, especially for having an 1/8" shim in there.
Are you sure that you installed the offset bushings correctly in the UCA's? Because I've done this more than few times and set for maximum caster I've pretty much always had the camber be slightly negative and the caster be at least +3° or more.
Is your ride height close to factory? What strut rods are you using, and if adjustable, how did you adjust them?
I am sure that I installed the bushings correctly...but, I will re-visit that.
Factory strut rods with new 2 piece bushings with the cups placed with the bulge towards the rubbers. I left the control arms, strut rods and front shocks loose and set the ride height at 1 5/8 inches as per the FSM. After the ride height was set, I tightened the strut rods and torqued them to FSM specs (45 or 50lbs if I recall correctly). Then the control arms to 145lbs, and finally the shocks.
EDIT: When I installed the UCA bushings, I installed as to make the front arm as long as possible and the rear arm as short as possible.
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Ok, well that is the proper way to install the offset bushings.
Do you have fine or course thread strut rods, and which bushings did you use?
Fine thread bars and Moog 2 piece bushings.
What part number on the bushings? They're different 67-72 and 73+
I don't recall the number...Pretty sure that I spec'd the correct ones.
My measurements from lbj to frame reference are both identical. The numbers that I got on the passenger side (3/4* positive camber and 4 1/2* positive caster) are what I expected to get on the driver side. Trying to lose that 2 degrees of pos. camber while maintaining decent caster is driving me nuts. I am at a loss as to what to do next. Best that I got was .4 negative camber and +2 positive caster....and that's with .125 shims between the lbj and knuckle.
Should I be trying different combo's of the offset and standard bushings in different locations?
BTW....My strut rod rubber bushings did not use metal sleeves.
I'm not all that surprised that the lower ball joint to frame measurement is the same. The strut rods are a good thing to rule out, but they shouldn't effect the camber setting much, really only the caster. The camber measurement is the one that seems further out, but 5.5° caster is more than folks typically get with just offset bushings so I thought I would ask about the struts.
The camber issue is more likely to be a UCA or UCA mount issue. I wouldn't really mix and match UCA bushings because you will lose more caster adjustment by doing that.
Can to post pictures of the UCA's and the UCA mounts on the frame?
You have another option as well- lowering the car from the factory specs increases negative camber. But it would be best to figure out why the camber is so positive to begin with first.
Maybe one more thing to check before moving to the upper control arms. Check the distance from a centerpoint out to the lower ball joints. This isn't likely to be the problem but should be fairly easy to rule out.
If that checks out then both lower ball joints should be square with the chassis both front to back and side to side assuming measurements are correct.
The upper ball joints will be a little more challenging to measure. You are looking at the same measurements as the lower ball joint equal length front to back and side to side. These measurements should agree with your current alignment numbers. In other words if you camber measurement isn’t the same on each side your side to side center to upper ball joint measurement should reflect that.
A potential cause for misalignment if the upper and lower ball joint position look to be square is a bent spindle.
If the upper balljoint position is off check the upper control arm mount position.
If that looks good measure the upper control arm itself.
Think of it this way. If the position of the upper and lower ball joints are square to the chassis side to side and front to back on both sides and the spindles are true then your alignment specs, caster and camber will be the same on each side.
Another way to approach this might be to replace the spindle and control arm with known straight parts. And if that doesn't fix it then start in depth measuring. A qualified frame shop should have all the tools to take these measurements. That might be an option if you can't do that on your own.
I will take a couple of pics and post them this weekend.
Interesting.....I have found that jacking the front of the car up by the k-frame (raising ride height?) actually makes the camber more negative.
Thanks for your time....Stay tuned!
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I'll mess with this this weekend. I have spare parts so I will try the control arm first, then the spindle. The car is just being put together and I'm in the home stretch. LOL....I'm thinking if a frame shop needs to get involved I will cut my losses and part it out.
Wow, easy there, have You loaded the driver seat with Your weight yet?I'll mess with this this weekend. I have spare parts so I will try the control arm first, then the spindle. The car is just being put together and I'm in the home stretch. LOL....I'm thinking if a frame shop needs to get involved I will cut my losses and part it out.
Trunk has enough weight to simulate a full tank of fuel, but that's it. No interior or glass.
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