Rear Thrust angle- shorten control arms?

The Cock Father said:
I feel like you're exactly right. But I'm very confident that at the exact same length, my thrust angle is still way off. This is with a new Dynatrac 60.

My thrust angle was 0.27 degrees. I then shortened passenger upper and lower control arms one full rotation. This improved my thrust angle to 0.22. That is barely in spec according to the alignment shop.

By my theory, I can probably take out another three turns to get closer to 0 (presumably 0.07 degrees) but then my passenger side rear control arms will be four full turns shorter than the driver side. That seems wrong, but I can't reduce the thrust angle any other way (that I know of).

I feel like my axle is centered and I measured several times to confirm.

Any insight?
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When does it pull to the right? Accel, decel, or cruising?
 
The Cock Father said:
Cruising. I don't accelerate hard and don't notice it then.
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Honestly, I would call Dynatrac and discuss it with them. Or even get a 2nd opinion from another alignment shop just to make sure. You should not have to chance control arm lengths from side to side in order to fix this. Any pull before the axle swap?
 
WJCO said:
Honestly, I would call Dynatrac and discuss it with them. Or even get a 2nd opinion from another alignment shop just to make sure. You should not have to chance control arm lengths from side to side in order to fix this. Any pull before the axle swap?
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Nope. No pull at all.

Thanks for sharing. I can't figure it out. I did wonder if something is not straight on the axle. But would doubt it since Dynatrac has a ton of QC and everything is built with jigs...
 
With a helper, you could measure the actual wheel base and compare side to side just to be sure. If it's off, select a fixed point on the frame that's symettric on each side and measure from there to a similar point on each side of each axle to see if something truly is off. Like you said, very unlikely the axle brackets weren't welded correctly. But also strange the pull wasn't there before the swap.
 
Thnaks.

That's my exact plan this morning- try and figure out where the discrepancy may be, as something is definitely not right. I'm going to measure again and again before I adjust CAs. Hopefully that'll provide some sort of insight.
 
The Cock Father said:
Thnaks.

That's my exact plan this morning- try and figure out where the discrepancy may be, as something is definitely not right. I'm going to measure again and again before I adjust CAs. Hopefully that'll provide some sort of insight.
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If you don’t mind, wondering what your solution was? I’m putting my XD60 on and was surprised that I had to extend my lower control arms 1 inch longer than stock to get the pinion angle below 6 degrees. Although this isn’t the same problem you had, I’m concerned about creating a similar issue. I’ve measured and measured. My axle seems to be centered and perpendicular. Won’t know until I get it on the road. Hoping for no surprises but in the event of a pull to one side I would appreciate knowing what you did to fix it!
Thanks!


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