C1 camber adjustment
During my frame off on my '57 I disassembled the front suspension. I replaced all the seals and kingpins. Everything else looked good. Now on wheels I wanted to correct too much negative camber on one side. I inserted a 1/4" allen wrench into the upper control arm pivot pin but it won't budge. I reefed on it a bit and even tapped on the wrench while under tension but nada! It won't turn. It shouldn't take this much effort. I don't think it necessary to loosen the bushings and that sounds counter productive. Any ideas? Thanks, Frank Condron, Edna, Texas.
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Re: C1 camber adjustment
Assuming the pinch bolt at the top of the spindle is loose, the eccentric bolt should turn. Can you move the pinch bolt up and down once the nut is loose? Remember the pinch bolt is what the eccentric pushes against to move the top of the spindle support fore and aft. The eccentric may be at the limit of adjustment and binding; like a bolt that is backed into a blind hole. If you have the suspension raised, the coil spring will put force on the eccentric bolt. Put the tires on the ground.
The last thing to try is to tap a screwdriver into the pinch bolt slot and expand the clearance that the hole in the spindle support has on the eccentric.
I find the bolt is indeed tight and I use a long 1/4" allen with a 1/4 drive ratchet.
If you can get the settings to the nominal values (2 caster, +1/2 camber, 1/8 toe) and not just in the range, the car will steer well and not be subject to wandering with bias ply tires. Getting those settings may require a second caster shim. It worked for me.
Joe -
Re: C1 camber adjustment
Thank you Joe. Indeed, when I loosened the pinch bolt. Voila! I've got a GM service manual and I saw nothing about loosening it. I jacked it up and took off the wheel while I was problem solving and once I loosened it I got plenty of Camber movement. Now, back with weight on it the eccentric turns but I am not getting anyway near 0 to !/2 degree positive. So I'm still playing with it. Stay tuned. Thanks again.Comment
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Re: C1 camber adjustment
You have two suspension measurement values that battle each other. The eccentric bolt is at the end of the A arm, and is therefore set at an angle. It is not parallel with the sides of the body. Adding caster by screwing the bolt to move the upper end of the spindle support back towards the rear of the car also removes camber. Take a particular setup (e.g. at 0 deg caster, camber is 0 to 1 deg. positive range. At 1 deg caster, camber is -1/4 to 3/4 range). Once the caster is at its maximum value (all the way to the rear of the A arm) camber will be at its minimum range (-1 to 0 camber).
This was my issue. I could not adjust the eccentric bolt to where it was needed to be. It was a compromise.
I added a second set of caster shims and now have 2 deg. caster, 1/2 deg +camber. With new bias ply tires, it is so smooth to drive. At 122 MPH, the car gets a little light, but steers straight.
Previously, it appeared having the same camber reading on each side was more important than the same caster reading. Straight line tracking from caster may not be as significant as straight line stability from camber. I have a Fastrax tool and do my own alignment adjustments.
These C1 front ends are prone to frame bending from collision with curbs. There is a weak spot in the frame just behind the crossmember. That will reduce the maximum caster because when colliding with a curb, the crossmember will rotate in direction that reduces caster.Comment
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