[bstark]

Jerry: I'll hazard a response based on my experience so far. I put the jack under the center of the plate that fastens the spring pack to the axle, center the depression in the head of the jack over the "tit" from the spring pack that locates it in the plate and slightly protrudes through the bottom of the plate so that you are lifting the axle at the same point that normal suspension forces would be acting on the system. And lift the axle just enough to remove the wheel. All things being equal you are putting no more stress on the Trailair than it would be subjected to if you were to run over a small speed bump.