Eccentric UCA Bushings Orientation

[340inabbody]

Guys I can really use your input on this. I am trying to reconcile/understand how to properly orient the eccentric/offset Upper Control Arm bushings (Moog K7103) used to increase Caster.
I threw this drawing together because I don’t want to reference the arrows on the bushings as I understand some bushings had the arrows reversed.

I also wanted to fundamentally understand the geometry rationale for the orientation.
Lastly I believe the K7103 was devised for cars so out of whack that camber could not be corrected without the addition offset. So install directions were based on this.

Ok so can I hear your comments on my drawing? What case is correct for caster increase?

When I look at it seems like case 1 is the correct orientation for passenger side.


Case 1 passenger side
Case 2 neutral stock
Case 3 driver side

Thanks guys for your help on this!
Ron

 

[340inabbody]

This is my take on how the bushings as oriented above (case 1) would move the UCA. I could be wrong but this is what I would like input on. I am in the middle of assembly so any input would be greatly appreciated. I want to make sure I did this correctly before I set in the ball joints.

Another view of the UCA movement due to offset/eccentric bushings. Ball joint moves in an arc towards the rear of the car to increase caster.

Note bushings oriented as above.

Case 1 passenger side
Case 2 neutral stock
Case 3 driver side

 

[Vaanth]

Case 1 is the orientation for increased caster and the relative movement for the driver side upper control arm is correctly shown in your drawing.

 

[sccachallenger]

Your second drawing is correct. On either side you're trying to move the upper joint to the rear of the car, behind. where it is with std. bushings.
Hopefully your camber will be acceptable with this setting.

 

[340inabbody]

Case 1 is the orientation for increased caster and the relative movement for the driver side upper control arm is correctly shown in your drawing.

Case 1 I seeing moving the arm correctly for the passenger side as it kicks the front of the uca out and the rear of the arm in rotating the arm clockwise moving the ball joint out and backwards. Right?

 

[Vaanth]

Case 1 I seeing moving the arm correctly for the passenger side as it kicks the front of the uca out and the rear of the arm in rotating the arm clockwise moving the ball joint out and backwards. Right?

You have it right.

Case 1 is the orientation for the passenger side, and Case 3 is the orientation for the driver side as in your first drawing. Then the relative movement as shown in the second drawing for the driver side is correct for Case 3. Similarly, rearward motion on the passenger side for Case 1. My first answer didn't phrase that well.

 

[340inabbody]

You have it right.

Case 1 is the orientation for the passenger side, and Case 3 is the orientation for the driver side as in your first drawing. Then the relative movement as shown in the second drawing for the driver side is correct for Case 3. Similarly, rearward motion on the passenger side for Case 1. My first answer didn't phrase that well.

No! You are right! Heres why>

I think I maybe wrong. I was thinking of the centerline as if a rod was going through the two holes. But there isn't. It should be thought of as a pin! In that case I am backwards. I see it now and my mistake.

Case 1 is for the driver and case 3 is the passenger side. It’s a simple offset from a pin not axel.

 

[340inabbody]

It’s confusing because you have to use the correct frame of reference. The reference should be a fixed center line. The offset is strictly in the upper control arm so moving the control arm away from the centerline would require that the bushing be thinner at the inner point not thicker. Hence moving it outward!

 

[CFD244]

Orient the bushings to make the front arm as long as possible and the rear arm as short as possible. Max caster, but you may be struggling to get neg camber......That's my problem as we speak. Best I could do is neg .25 camber and pos 1.5 caster.

 

[remytherat]

You have it backwards. Remember the bushing is fixed relative to the arm, so moving the bushing inwards pushes the arm outwards.

Note how at the back, the arrow points inwards, meaning the eye is offset outwards.

Case 1 driver
case 3 passenger

 

[340inabbody]

Orient the bushings to make the front arm as long as possible and the rear arm as short as possible. Max caster, but you may be struggling to get neg camber......That's my problem as we speak. Best I could do is neg .25 camber and pos 1.5 caster.

Are you using eccentric bushings? Both front and rear or just front?
Ie How are your UCA bushings oriented?

 

[CFD244]

Are you using eccentric bushings? Both front and rear or just front?
Ie How are your UCA bushings oriented?

Yes, the Moog offset bushings. On the front arm, narrow section towards the frame and on the rear arm narrow section towards the ball joint. Try to picture the front arm being pushed out as far as it will go and the rear arm pulled in as far as it will go. Also, be aware that you may have to touch up the rear arm with a bit of grinding. My rear arm, at the pivot, contacted the fender apron not allowing for the rear arm to be pulled in the full amount offered by the cam.