Thanks, 04superduty,
Good tip & worth repeating. On my tandem axle trailer when I occasionally had to load up to 2,000 pounds on the back of the deck and then winch it forward, I used a couple of axle-stands under the frame.
I also had a fun ride once when I forgot to put the wood blocking I normally used under my fork-lift trailer's rear. My little Clark forklift is small, but it weighs 4,000 pounds. As I drove it onto the back of the trailer there was enough leverage to lift the tow vehicle's rear end enough to break traction and everything started to roll/slide down the slight slope. I realized that there was not a lot of choice in this situation and just kept driving the forklift past the axle and then things slid to a halt.
Now you know why I do not fail to think about this tip when loading a trailer.
P.S.: This is another reason why the pro's chock all their wheels. I have seen signs on loading docks reminding the drivers that they get on service until the trailer wheels are chocked.