I've had few ford trucks (1982 Bronco, 1990 F350 & 2000 F150) and always notice not only on my truck but many others too.

Why is it that front passenger side suspension gives up. If I look at my truck from the front. I can see that passenger side axle/tire is not fully straight like driver side, so my truck is lower on the FR side.
is there anything I should replace? Rods, shocks, leaf pring.

I took it to FORD and the so called advisor said he was not sure and he's never seen or heard if this problem :O

Any suggestions?

 

I would try a lift leveling kit from www.truckeo.com i put one on my super duty and it seemed to solve that problem.