If you have to unload on uneven ground, if you follow the right sequence, it takes all the guesswork out of it and doesn't take any longer if you mark the positions of the jacks when you have it jacked up to unload. Then you can re-set the camper to that position exactly when re-loading. Just make sure there arent any big bumps or dips the wheels will go over while pulling in or out.
Otherwise, I've unloaded on significant cross slopes, downslopes or combination of.
-Run jacks to ground
-Lift camper off at the same slope as the truck is sitting until clear of truck bed, don't level camper up and then lift.
-Mark or write down jack heights for each jack before leveling camper up.
-Adjust camper to level and desired height after truck is out.
-When re-loading, bring camper up close to height and adjust to previous jack heights, then the truck will back right in the same it came out and be parallel with truck bed.
