any advice

A 3 ton (6,000 pound) will lift just about any RV or trailer axle. The exception being large gas powered "C" and "A" and DP.
10-12 ton is overkill and unneeded weight IMO.

X2 on the HF 12 ton low profile. Works great

Just a note on Bottle Jacks. I have them too and used one in my driveway to replace a flat tire on my camper. I had to jack the camper up so high to get the tire off that it tilted the camper. First attempt failed. The jack kicked out before it was up high enough to get the tire off and the camper came crashing down. Fortunately, there was still one good tire on the camper so it made a big noise but no injury and no damage to the camper. I only mention this to be very careful using bottle jacks on campers. There's only about 1" of contact with the camper frame and top of the jack. Now I have those curved ramp things to raise the camper if I ever need to change a tire again.

I use the jack for my Ford Super duty. When I got trailer I tried out the truck jack and it worked fine. Had on opportunity to actually use it on the road when I had a puncture in a tire. I like the idea that with the long handle to operate jack, you do not have to crawl under trailer to get it in and out.
Also make sure that you have a tool to fit trailer lug nuts, that will actually loosen the nuts.

I carry a bottle jack in the truck along with two jack stands. This offers easy to store and more flexibility than a floor jack for on the road or in the campground repairs. I do have a floor jack and 6 jack stands at home for the times when I need a serious jack solution.

I would suggest something like this. A low profile could be beneficial. If a flat occurs, there may not be sufficient height to get standard jack. A heavier capacity jack then what you need makes it easier to lift load.
12 ton low profile bottle jack

Rich,

The following is not a joke....

Something you need to do before you buy a jack, is let the air out of a tire. If you buy a jack that is 1/4" too tall...
Measure both under the axle and possibly the balance link (where Dutchman is showing) but only a floor jack with a big lift plate will like that. Remember, if a tire blows and shreds, you may be down on the rim and that can need another inch+/-.

Bottle jacks come in all kind of sizes. If you don't know the axle load, at least get the loaded trailer weighed so you have some idea.

Assuming you have chocks in your kit, you will still need a wrench. Buy a good Cross wrench (aka 4-way) and make sure it has the size for the trailer nuts. (Some these days have metric ends.)

If you aren't carrying a spare, don't bother with any of this. The road service guy should have all that.

If you are going to carry this kit, loosen (and re-tighten) a nut or two at home, and try jacking up from a flat tire too. You don't need to find out if the kit doesn't work at the side of the road, in the dark, when it is raining and cold.

Matt

I have a hydraulic bottle jack that I use for my motorhome. They're not always the most convenient to use, but they are relatively inexpensive and reliable and don't take up a huge amount of space. They do generally require comparatively much clearance underneath whatever is being jacked up, not a problem with the class C chassis.

Floor jacks (like DutchmenSport shows) are more convenient to use but not always the handiest to stow in an RV. Many are also relatively light duty, 3 ton capacity or so. I have one that I use for maintenance on my car, mostly rotating tires (in combination with a couple of jack stands, which allows raising all four wheels off the ground simultaneously and so avoids having to shuffle a jack around a lot in the process).

No jack should be relied on to support a vehicle while working underneath it. Proper jack stands or other safe, solid supports (e.g. well-constructed cribbing) are essential for that. For jack stands, check the load ratings with a bit of care; often the specification is per pair rather than individually.

DutchmenSport wrote:
I have a smaller hydraulic floor jack I carry in my truck all the time. I use it for all sorts of thing. Only problem, it's not very tall, so I usually have to put lumber under it. I've never tried lifting the trailer, but it does lift the truck and car OK.

Here's a beefier version when we got new tires last year. Not mine, but have seriously thought about getting one like this for years now. But my smaller one works OK for what I need:

Well great on pavement, but a real pain on gravel, get a bottle jack.

Harbor freight 10 ton hydraulic bottle jack. Easy to carry, not too heavy and reasonable.