just bought a 1998 F150XLT and noticed that the backend of the bed is not parallel to it's front end. This makes it look, to those following me, like my butt is sagging to the left side. It looks ok underneath, as far as i can tell, but wonder what the cause is.. a bent frame?
Anybody have experience with this? What may be causing this? Any remedies? Do I have to shim the back left mount?

 

air shocks

 

My buddy has this problem on his ranger. Is that all it is? New shocks? Heck, I'll go buy them for him, looks like crap!

 

I had that problem on my 01 and I had new springs and shocks put on it and it leveled out fine. I was told by the dealer that the springs and shocks on those body styles were not very heavy duty and that if there has been heavy loads in the bed that it will sometimes cause the truck to sag one way or another. New shocks and maybe springs will help you..!.!.!

 

swap the two leaf springs from left and right, and should help... over time, the weight of the driver, and gas tank on that side makes them sag faster. Or you could go get them "re-arced"