2012 xb. Lowered on nf 210s. 18x7 42mm 225/40. Rear alignment toe spec is -0.02"/0.10". After springs rear toe is at 0.17". Added 1/16" shims to both front knuckle mounting bolts and specs jumped to -0.33". Total movement .5".

Logically, this tells me that if I lowered the shims to a 1/32" I would have a total difference from original spec of 0.17" to -0.07 (still out of spec). Total movement .25"

If I lowered shims to 1/64" I would have a total difference from original spec of 0.17" to 0.04" (pretty darn close to the center of .06"). Total movement of .125"

Is this correct? I am far from an engineer, heck, i'm only allowed to walk without a helmet while being accompanied by an adult. I know the numbers make sense but do you think thats what will actually happen?

 

Ask an alignment shop. I've been replacing tires every 6-8 months because I haven't even tried aligning the rear. I'd start with the smallest shim and go from there.

 

Success!. Quick recap: 2012 xb nf210 drop. 18x7 42 225/40

Rear toe Spec: -0.02/0.10"

After springs: L= 0.19" R= 0.17"
After 1/16" shims: L= -0.33" R= -0.33"
After 1/64" shimis: L= 0.03" R= 0.01" (not at the "perfect" 0.06", but I'll take it)