[Motor31]

First off Mav, lose the all caps, it's rude to "shout".

Secondly you cannot lift half the weight on the trailer by jacking one side of one axle as half the weight of the trailer is not on one axle. You are only lifting the quarter weight that is supported by the tire on that side of the axle. Should you try to lift both axles on one side you would then be correct however it is not necessary to do so to just clear a flat tire from the surface of the road.

Thirdly you are not going to be able to lift the trailer frame should you have a flat on the side of the road unless you have a system that allows the entire rig to be lifted like a secondary hydraulic lift. Should you require that kind of operation you will only be able to have the trailer loaded on a flat bed trailer then taken to a shop. Frankly I'd love to see something like that tried. It would be interesting to see how the tow truck would move a 5th wheel trailer, without a crane and sling straps, onto a flat bed. It would also require an oversize permit for height as well as all the other requirements for moving an oversize load on the roadway.

In a perfect world you would be able to lift the frame any time you needed to change a tire but then again in a perfect world you would not have a flat.