Hey Charly,
The 8400 is a tighter fit than most other lifts. There is more metal at forks. Adjustment is by rotating eccentric pins, under the battery. You must remove lock bolt, then tap out pin (from opposite side) just enough to clear pin head from frame stops. Turn pin hex to get truck at desired height, on each side, evenly. But, before doing this, check the wheels to see if they tuck in flush with body. As for getting stuck in skids, Raymond Factory fix was to grind stops away, (WHERE TRAIL FORK RAISES UP INTO FORKS) allowing wheels to travel farther up, giving more clearance. Grind any excess metal at tip area, and smooth it out with buffer. I've done this factory fix before. Also, caster type makes a difference too. Spring type works best for loading trucks as it gives. Rubber type is more solid and prevents sway, but gets you stuck on dock plates as it lifts the tractor, binding the skids. Get this adjustment right, or elses the truck cant stop or turn on tight corners, or it shakes side to side and is hard to steer. Extra shims from Raymond are a gazzillion dollars each, so be precise, or make em!