If you step on the rear bumper pushing down, and release the car bounces 5 times. Almost like there are no shocks. If you go over a bump the bounce is noticeable.

 

that sounds like shocks to me. they could be valved light for the springs you are using?

 

Who made them? It's possible they made it thru production with no oil in them. They weren't installed upside down, were they?

 

I think the OE shocks are single piston type. Dual piston sounds sexy but they in fact are not as rigid as the single. That is what you want to pay attention to when buying shocks. Duals give more of a soft ride but will dip more on bumps.
That said, the way to test a shock is off the car, against a new one of the same piston number. Compress it and see how long it takes to recover vs the new one. Should be quick, if its slower than the new one you can tell how bad it was.

 

I always run them through a few compressions with the top installed before attaching the lower side. you will feel air and the shock is weak sometimes until you do this. It's from them being stored on their sides from what I was told.

Max

 

Now you're talking about gas filled shocks. With ordinary hydraulic shocks, you shouldn't be able to easily compress or extend the piston rod. The more resistance, the better it is. Gas filled shocks add gas pressure to the compression rate and allow them to rebound easier. They basically act like coil-over shocks without the exposed spring. When the gas leaks out, they still function like a normal hydraulic shock.

The design of a shock absorber is in the valving. It's a piston in oil with flow valves to allow the oil to escape to the opposite side at a controlled rate. Most newer shocks have differential valving in that they compress harder then they rebound. In drag racing, people used to use special "uplock" shocks to get the front end weight high quickly, then hold it up to keep the weight on the rear wheels for a longer period.

Whatever shocks you put on the jeep, they aren't doing their job. I have Monroe Sensatrac shocks on my WJ. If you stand on the bumper, it goes down a bit. When you jump off, it just comes back up and stops.