I did figure it out. The shaft is hollow inside. When you rebuild the cylinder the last step you need to do is install the piston and shaft into the shell. Push it all the way down and then fill up the shell with hydraulic fluid. Then you install the cap. This is how they are dampening it. When you go up, the fluid is pushed into the shaft, then when you come down the fluid will come back out of the shaft and fill the top chamber up. I like the design of it. But it is the first for me.
thanks for all your help