You can "sort of" pre-level simply by extending the jacks a bit and looking to see where the bases of the jacks in relation to the ground, or in my case, the blocks they will be sitting on (I use no more than 2 lego blocks on any jack). You will see if one side or front/back is higher then I block accordingly to get them relatively level. Another thing I was told by a CW tech was to always extend the front jacks at least 6" and then insert the pin to keep them from having to extend too far and end up out of stroke. I would caution to be somewhat judicious with that as I recently decided to just extend them on out to 9 holes based on the terrain. Nothing bad happened really but the rear jacks had to extend so far to get to level that my back tires were off the ground....probably should have stuck with 5 and the would not have had to extend so far.
