What causes "the sag"

[yammerslammer]

I've seen alot of Expys that seem to sag in the rear, what causes that? I'm sure bad airbags is one reason, but mine is saggin and it doesnt have the air ride. It seems like all of the weight is on the front, and that would make the front sag more.

 

[fiveohpoepoe]

Depending on the mileage, the springs could simply be soft. Also, the shocks, though not known to actually lift the vehicle, could be soft. Does it bounce more or anything out of the ordinary?

 

[yammerslammer]

Truck seems to ride fine. I was just curious more than anything. thanks

 

[napew2009]

rear sagging

i have a 99 expy with no air bags. I thought it was a simple fix of new rear springs and shocks, but it wasn't it. Apparently it adjusting the torsion bar. it leveled off.