I brought THREE jacks with me: a 12 ton high lift bottle jack, a 4.5 ton low profile high lift floor jack, and the normal screw jack that stows under the seat of the truck.
The bottle jack decided that it wouldn't take any load at all. Seems like a bad seal.
The floor jack work fine, until it was about 2/3 up to its full extension; when suddenly it wouldn't lift any more.
That's usually a symptom of a jack over its weight limit, but there is no way a 4.5 ton jack should be overloaded by a max 5 ton trailer (ok, lets say it's overloaded, and it's 6 tons instead of five... STILL).
The one that actually did the job, was the little screw jack that comes with my truck. In fact it worked perfectly, quickly, and easier than the floor jack... It weighs about 2 pounds, the floor jack weighs over 100...
The reasons it took 3 hours were threefold:
- I tried the floor and bottle jacks first, and NEITHER decided to work
- I didn't think the jack that came with my truck would WORK for something like this, so didn't try it until I had already workd a dozen different angles on the other two jacks
- I refuse to run without a spare, so we stopped by a tire shop off the next exit, and got one (which took about 45 minutes, including the time for the detour. The tire shop took 20 minutes to mount and balance the tire on our existing (and thankfully still good) rim.
I made a half joke after remounting the new spare on the trailer tongue "Now we're good, so long as we don't lose two at once"...