Possible crooked rear axle/alignment issue

Recently had Kings installed on all four corners along with a Deaver Expedition Pack in back. Initially set the front CO's to 2" just be safe since I had yet to purchase aftermarket UCA's at that point. Truck pulled to the right a little at this point - not a huge deal. Went ahead and had 265/75/R16 Toyo M/T's installed. After that the truck pulled way right. Went back to the shop and had an alignment done. The tech told me that the truck was wayyyyy off - ended up setting the alignment considerably to the left (far enough that if all was well I would probably look like a NASCAR driver spinning in left hand circles) to accommodate and there was still some right-bound pull. Tech wasn't sure what was causing it. Went back to the shop where the lift was installed and decided to get the TC UCA's which was supposed to fix the problem. UCA's were installed and the truck taken back for alignment. Caster was better but tech still had to adjust left to help eliminate the pull right - and there's still a right pull. Tech did some more tests and established that the Thrust Angle (.20 which doesn't seem too high) was off - measured axle to axle and found that the rear driver side tire is farther forward than the passengers side - the axle is crooked. Took it back to the shop who did the lift and they say everything is fine. . .
Long story short lifted and the truck pulled - added tires and it pulled more - added UCA's which should have corrected the problem and still have a massive pull right which is being accommodated for by setting the alignment way left. Possibly the rear axle but no one agrees.
Will post alignment specs later today but wanted to get the question out when I had time.
Any help would be greatly appreciated.

 

how big are the center pins on the deaver packs? i have seen small center pins allowing slop at the axle fore and aft, 1/8th in back on oneside, and 1/8th forward on the other will make the truck definietly crab down the road.

 

You need a four wheel alignment that measures the rear axle thrust angle to confirm or deny your speculation that the rear axle is the culprit.

 

The Thrust Angle is at .20 as far as I can remember. I'll have the exact number in a few hours. From what I've found that's not necessarily enough to warrant any drive ability issues although I'm not sure.
I'll definitely check into the pin size.

 

I've got this problem too. My axle is shifted 1cm to the right - determined by hours of measuring to the point I'm probably overthinking. It's a 2014 TRD OR DC 4x4, stock rear leaf springs with ToyTec Progressive AAL added. What is weird...when the truck is up on stands and the rear hanging it centers back up. I've loosened the U Bolts and pushed it left which the axle rested on moving casters in loose bolts. I can not figure out where the shift is occurring when it's back on the ground. Thinking of ordering complete new leaf packs cause the right drift is no fun and the only cause I can sumize is the existing leaf setup.

Ideas welcomed.

 

Correcting thrust angle is actually not too hard. All you need is a winch or come-along.
My thrust angle was off when I made an OME bastard pack a long time back. Shop said they could do it for too much. So I took it home, laid out my alignment measures (borrowed my neighbor's contractor laser), and tugged it into alignment with my winch and a chain.
Loosen the U-bolts. wrap a chain around the axle tube on the end that is furthest from the front, then attach the winch and bump it a hair at a time; if using a come-along, attach it to the recovery hook at the front of the frame. Once you get it where you want it, tighten the U-bolts, and take it to the alignment shop to verify you did it right. If you're like me, you'll overshoot several times in both directions, and spend way longer on it than you need to (damn perfectionism!).
Use this link to help set your angles. Who knew you would ever need to use the Pythagorean Theorem in real life?