Here's what I was talking about:



The arrows are pointing to the pins in the center of the springs. The pins fit into the holes in the spring perches:



On the bigger trucks I used to deal with, it was a bolt. Some of our trucks delivered fuel to loggers in the mountains, so we frequently broke springs and tie bolts. I'm not even sure if tie bolt is the real name for it or not, that's just what we called it. The most common cause of the bolt breaking was loose u-bolts. A leaf cracked in the center would also cause them to break.

These bolts or pins are what keeps your axle aligned. If the bolt breaks, the axle can shift back and forth on that side. That's the simplest thing I can think of that would let your axle be out of alignment. A bent frame could also cause it, but unless the truck has been hit very hard, I doubt that's the case.

Easy way to check is to look at the springs where they fit on the perches. If one side has been moving, you'll be able to see the wear marks on the spring.

 

no i have not checked the u bolts on the leafs...good point though.

i just wish it was warmer out to fix this if it were the prob.
i have a week before time off to check, but thanks again for the lead.
once again...forum to the rescue.

 

ok, well i looked all around the axle and leaf mounts(?)
no signs of rubbing at all, the rust is pretty much in tact on both sides.
so maybe it is just a birth defect.