There is a plate that the axles are bolted to on each side of the trailer, and a floor jack will go between the two tires and jack up the trailer on that steel plate. I only caution you to not damage the tank cover located directly behind the plate, and to make sure the jack has good contact with the plate to insure it does not slide off.
Additionally, there is supposed to be a location behind the axles under the frame marked as a jack point, but after the trailer has been in use for just a little while, the marking seems to go away.
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