KINDA IGNORE WHAT I HAVE WRITTEN IF IT DOESN'T FIT YOURS. My posts aren't exactly like any at the web site. I have two allen screws to adj side play,and one to adj preload(the site mentions allen key preload)
I recently came by two of these. It took a while, but I finally found how to adj it. There is an Allen bolt in the bottom; this adjusts preload, and is critical.
Those side adj are just for stiction.Have them as loose as possible without having much sideplay(oil them also).If they are too tight, it won't move much and the ride won't be improved.
Set the preload so it is just on the edge of moving with you in your natural riding position.There might be a way to shim the preload, if you can't adj it.
It took me a long time to figure the seatpost out. I've never has a sus. seatpost that actually seemed to work.THIS POST ACTUALLY WORKS. MAKE SURE YOU SET THE PRELOAD SO IT IS JUST ON THE EDGE OF COMPRESSING, BUT NOT COMPRESSING, WHEN NORMALLY SEATED!!
Luck,Charlie