Take the suspension apart and check each part. I think it's the shocks. They can wear out without showing signs of wear. My basic test for shocks without removing them is when you hit a bump or go over railroad tracks or something, If the truck bounces up and down more than 3 times, it's time for new shocks.

 

I would be willing to bet the coil spacers are to blame... especially if they're made or polyurethane.

 

What's an upper and lower coil spacer? Lol

 

Just like it sounds, one mounts on top of the coil one mounts under. Upper is a 1.5" daystar and the lower is a 1.5" top gun customs off eBay. The lower one is metal the upper is poly. Wouldn't recommend this setup to anyone though the spring is very compressed and the ball joint angles aren't ideal. I put the swaybar on yesterday and it evened it out to probably 1/4 inch in the front still way off in the back..gonna try switching shocks left to right in the rear.

 

Just let half the air out of the the tires opposite the saggy side, and voila! Fixed.

 

That's a joke right there. Probably a worn out component as mentioned-shock or spring or something.

 

2nd Gen. Rams are known for sagging on the driver-side. Between the driver seat seeing more weight more often (obviously), the battery, and the gas tank, they are known for simply wearing out the springs on the driver side.

 

Never heard of a lower coil spacer but whatever you say chief. Definitely sounds like a dumb way to lift a truck though

 

It's no different than putting a spacer on the top your still applying force to spread the upper and lower control arms apart. Apparently things you haven't heard of are dumb?