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Correct caster or perpendicular axle?

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Old Sep 17, 2010 | 02:28 AM
  #1  
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Default Correct caster or perpendicular axle?

I have 2" OME spings that I was running stock control arms for a while. I was getting tired of the flighty steering at various speeds, so I found a deal on some Skyjacker adjustable front control arms and solid rears.

When I put the fronts on and played with the adjustments to get a caster angle around 4.5 degrees, my passenger side is running about 1/2" further forward than the driver side. I do notice a slight pull to driver, but the steering is spot on with no wobble.

Should I leave it alone? Should I get the axle perpendicular again?
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Old Sep 17, 2010 | 05:53 AM
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just to make sure we're on the same page here, you are making sure to set the control arms to equal lengths, right?
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Old Sep 17, 2010 | 06:20 AM
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If you have both upper and lower adjustable control arms, then shorten the right arms to be equal to the left arms. That should get rid of the pull to the left. If the steering wheel is off, you can correct that by adjusting the drag link.
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Old Sep 17, 2010 | 07:55 AM
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Yes, you need the axle to be perpendicular to the frame. If you don't you are going to get uneven tire wear, amoung other things. Make sure your control arms are equal lengths, then adjust your caster angle. It's best if you have a buddy on the other side and you each count the rotations and stop on the same count. Whatever you do to one, do to the other. Then get your caster angle as close to same as your axle as you can.
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Old Sep 17, 2010 | 12:26 PM
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Thanks for the replies. I have adjustable lower CRs, but the uppers are stock.

Their dimensions are not equal right now. They were close to equal, but the caster angles were off by a few degrees. That's when I started adjusting one, then the other. The angles became equal, but the axle is not perpendicular.

I had a feeling I should go back to square one.
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Old Sep 17, 2010 | 12:43 PM
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Originally Posted by el_campede
Thanks for the replies. I have adjustable lower CRs, but the uppers are stock.

Their dimensions are not equal right now. They were close to equal, but the caster angles were off by a few degrees. That's when I started adjusting one, then the other. The angles became equal, but the axle is not perpendicular.

I had a feeling I should go back to square one.
the caster angles are supposed to be off one side from the other. this is done intentionally from the factory. set your control arms to equal lenghts and you should be good to go.
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Old Sep 17, 2010 | 12:43 PM
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Default control arm lengths

Isn't it recomended that the right arm is slightly longer than the left, giving slightly more castor on the right to account for the camber in the rd. Teraflex suggest this, as do others?

Originally Posted by wayoflife
just to make sure we're on the same page here, you are making sure to set the control arms to equal lengths, right?
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Old Sep 17, 2010 | 12:48 PM
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Originally Posted by AussieTom
Isn't it recomended that the right arm is slightly longer than the left, giving slightly more castor on the right to account for the camber in the rd. Teraflex suggest this, as do others?
this would only apply to the upper arms as they are designed to control caster. lower arms are designed to set the position of your axle. even still, we're talking about a solid axle and the amount you can twist it is very minimal. fact of the matter is, you'll see very little to no effect from setting your upper arms at odd lengths and again, your caster is already off from one side to the other right from the factory.
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Old Sep 17, 2010 | 12:49 PM
  #9  
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Hmmm...

Here's my chart and it drives great!



I know in the installation of the control arms, it tells you to have set the control arms to the exact same length eye to eye.
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Old Sep 17, 2010 | 01:46 PM
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From: malone new york
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How did you measure caster? Becuase there is no milled sureface on the knuckle this is impossible to do with a protracter(angle finder).
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