Thread: '37 Oze build

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Good catch, I was thinking, "that sure is a clear shot from above" but it didnt register with me that the line is OUTSIDE of the tire completely

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Dave, I don't see at all how your explanation of caster adjustment can work, and it seems crystal clear to me that you have six big washers on the upper through bolt that would be used to shift the top of the A-arm back if you shifted them to the front. If you turn one rod end in and the other out you're going to create mis-alignment of the through bolt through the rod ends, and tend to impart a "twist" to the spindle as opposed to a "tilt" which is what caster is - the degrees that the spindle tilts back from true vertical. It's obvious that I'm not understanding your problem, or not understanding your explanation of what you're doing so I'm going to back away and wish you the best on your build. I'll not bother you further.

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My head is hurting just like Roger's.
It seems to me that "Caster is the angle between the upper and lower ball joint" CENTERLINES as Viewed from the side of the car. CAMBER is the angle as viewed from the front of the car. In the pictured suspension, moving the entire upper arm to the front or back using washers changes the Caster only. Screwing the threads in and out equal amounts on both threads changes the Camber only. Looking at a late model car with an SLA suspension, the same is true, there are shims instead of washers on the A-arm pivot shaft to change the caster. The pivot shaft moves in/out to adjust the Camber...the shaft is held via two big nuts and slots in the shaft. In a late model car, you dont bend the axis of the shaft....just like you dont bend the axis of your suspension by unequal length changes on the arm screws. Is I wrong? Thus, the axis of pivot for the top a-arm is parallel to the axis of pivot of the bottom arm. Changing the caster OR camber does NOT change the parallelism between the two shafts.

Regarding the wheel backspacing, most "knowledgeable" sources suggest that the line formed thru the two ball joints should point to a fore/aft line THRU the CENTER of the tire tread where it contacts the floor. I checked my TCI frame, this is true for it.

Maybe you guys now know why I bought a Hunter alignment system for doing chassis work!!!!!!!!!!!!

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what you aren't getting is that its not a Heidts front end you have and the twist on the ends of your a arms isn't acceptable---if you had swivel ( like a Heim) on there it would work

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I know I said above that I would not bother you further, but I'm going to give this one more shot. I believe that at the end of the day you will find that the IFS that you have is intended to be installed on your frame with the desired caster angle pre-set, and that your caster is not intended to be adjusted further. The description that you gave about turning one rod end in and the other out will put your rod ends out of alignment with one another in an increasing bind the more you offset the rod ends.

Let's put some numbers to it, assume that the upper rod ends are 1) 1/16" movement per turn in or out (1/16" pitch); 2) adjusted with eight threads showing on both rod ends, equally spaced out from the vehicle center line; and 3) the 5/8" through bolt fits smoothly through both rod ends at this balanced position with no binding at all, other than normal friction with the rubber inserts. Now we turn the forward rod end out four turns, moving it away from the vehicle center line 1/4", and at the same time we turn the rear rod end in four turns, moving it closer to vehicle center line by 1/4". The result is that the center point of the through bolt will be rotated in the horizontal plane, and the ball joint will shift back in an arc but the rod ends are now offset from one another 1/2", so the through bolt is going to have to be forced through the bushings if it will go at all. Now let's remove that through bolt and adjust the front out 8 turns, and the rear in 8 turns. You've again rotated the shaft, but now the rod ends are offset by a full inch!!

The only way to affect caster without binding is to trim the upper pipe portion to allow the A-Arm to shift fore or aft on the 5/8" through bolt.

You need to be talking to RideTech if they made your IFS, not Heidt's. Seems to me that someone's feeding you some bad basic information.

Originally Posted by daveS53

Using the rod ends to alter caster does not change that axis. All it does is move the upper ball joint forward or backward. As I noted, you must screw one rod end in and the other out, by the same amount or camber will be changed. The rod ends do both jobs. If you also want a camber change, then turn both rod ends in or out by the same amount.

I have to agree with Jerry and RSpears on this one! Running those ends at different lengths from the ball joint only forces the end tube to cock and will cause binding and rapid wear of the bushings in the tubes. Whomever told you otherwise was WRONG!

I don't want to argue with you but this is a mistake thinking it's okay because it isn't. The whole top assembly (those 3 tubes) needs to be in complete alignment and straight. Use of the 2 ends at different lengths for camber adjustment creates a bind situation and I strongly urge you to review and reconsider the situation!

I thought I'd try to say it with a picture.. the twist you see in the red circles is wrong! this whole shaft assembly need to be straight and in alignment.

Heidts Hot Rod & Muscle Car Parts#http://www.heidts.com/scripts/openExtra.asp?extra=15#

Originally Posted by jerry clayton

Heidts Hot Rod & Muscle Car Parts#

Jerry,
That link just takes you to the Heidts Home Page, and to get to the specific installation info you have to plug in what you're looking for. The info you're wanting to show may be there, but it's far back behind the curtain and we need the Wizard's permission to find it....