Ah hah! If there is no compressor/pump in the 'fridge; it is relying on natural convection to move the working fluid through the expanding section (where the propane heat is applied when it runs on propane). For that it would need to be properly up and down. I guess that I assume that the fridge is more or less square to itself; so a bullseye level in the bottom of 'fridge should give me the first target.
It sounds that for my next trip out I need to grab:
- a bullseye level for the 'fridge
- bring a whiskey stick of whatever length I can find around the house
- pick up a couple of stick-on bubble levels
Head out to a camp ground or someplace where I can find a place to set the trailer up.
Since I have stabilizers and not leveling jacks, I'll need to use the 'boards under the wheels' approach for side-to-side. While hooked to the truck; that's probably the most important direction to check. Front-to-back will have to come after I disconnect - but it would be smart to note how close and which direction I'm off.
Once the refrigerator is level, I can compare it against the floor. Not much I can do if they don't agree; but that would help me know what would be close enough. It must not need to be perfect, or it wouldn't work off of the propane while I pull the trailer down the road - that can only be level 'on the average.'
Then I'll want the slide out to see if that changes the initial side-to-side level much. Once the inside is good - it's time to put on the outside levels.
I like the idea of having the stick-on bubble levels near the tongue; since that's where the power jack is front to back. There is a lot of up and down there that goes on to disconnect the load distributing hitch. That affects the front-to-back.
Now to tell the wife and kids we have to take the trailer out soon - we have a mission.