QUOTE(nlik @ Sep 13 2009, 04:34 PM)
Yesterday went for 10k front/back wheel swap .. the usual. Found that even though there's the torsion beam which makes the rear wheels dead, mine is now slightly off alignment already.
So I guess that horizontal bar is not 100% true, or maybe bends overtime. The shop says there is a way for sentra owners to align the back wheel, but it'll cost around 100 each wheel, if not mistaken it will be using a shim?.
Also they found that one side of my lower arm bush is worn out already, so i guess it's time to replace it. He mentioned that cefiro's are worse as he had many encounters with cefiro with spoilt bushes.

Y don't car manufacturers use the adjustable camber screws for all cars as default!!. Those tyre shops really make alot of profit by selling, replacing all these stock camber screws with adjustable ones. If you don't change to adjustable camber screw, then they claim they can't do the alignment for you.
Anyway, more useless info for you.. the front wheel camber is -ve 1.5 degrees.
the rear wheel alignment is fixed for what car manufacturers deem as safe for 'normal' users
cheap lo 100 a side but ask him if he is sure of what he is doing. this is old skool alignment used on lorries with leaf springs all around. tell him you would do it only on condition ie replace beam if damaged etc etc.
hot tip, you want the rear set to 0

it can only be done if the beam is bent from the center. its a hollow U beam. good luck do post back your results if you plan to go ahead with it.
ok didnt see your out of alignment question. It can go out under these few conditions.
a) chassis damage
b) worn bushes
c) worn suspension components