[Tom Roper]

You're making progress it sounds to me. Specs "in the green" should not cause a steering pull, but radial tire pull will. It's one thing to get the wheels pointed in the right directions. It's another when uneven rolling resistance causes veering.

Your alignment shop is giving you the straight dope. The rear axle is solid, there are no rear adjustments that can be made, unlike cars with 4 wheel independent suspension, Maxima, Altima, Camry, Accord et al, which can require 4 wheel "thrust" alignment. Be watchful for dealers, or anybody who would try to sell a 4 wheel thrust alignment, as it would be a ruse to sell a more expensive alignment.

Many alignments are really no more than "checks" of alignments, or simple adjustments to the toe, which is where the steering wheel not pointing straight ahead got screwed up. I've fixed this problem myself by loosening the tie rod lock nuts, and wrenched both tie rod adjusters in the same direction, by the same amount. Since one is left hand thread and the other right hand thread, turning them both by the same amount in the same direction does not change the actual toe spec, it just re-centers your steering wheel. Often times, alignments only adjust the toe, and not the camber or caster, both of which have an effect of veering but are harder to adjust. On many trucks, a factory plug has to be drilled out before the adjustment can be made. Once removed, the new adjustment is also less likely to "hold" for this very reason, so one should be reluctant to adjust camber or caster unless certain it's out of spec. In the case of Titan I looked, found no plugs. Caster/camber is set by loosening the (2) large bolts holding the upper control arm to the frame. Adjusting is thereafter by trial and error. The technician using a Hunter alignment system will attach a transmitter to each wheel. The transmitter radio links back to the computer the wheel alignment spec, no more optical alignments with mirrors. The technician will adjust the upper control arm bolts repeatedly by trial and error until the computer puts the spec "in the green."

Alignments as delivered from the factory are usually the best it gets unless you hit something to knock it out, or got something bent. The factories use a rolling, road force alignment that's faster on the assembly line and more accurate too. For most people, I would use caution with alignments. Watch them do it, and better to verify it as a check of alignment only, unless you really trust the technician.

One last...

A sadly easy and unfortunate way to screw up your 4 wheel alignment is by using lift jacks on the wrong places on the frame. Our Titan fully boxed frame while strong, is still quite malleable and soft metal, easily bent as with all ladder frames. Looking underneath mine just before making this post, I noted there are jacking point arrows where it is reinforced, although not much help if you you are offroad you have to get the jack where you can get it. Also noted a pathetically dinky rear differential. Looks like it holds about a thimble of oil, and found one loose bolt backing out from my running board mount, but that's another story...