any advice

A 4 or 6 ton is plenty and fits with the RVing concepts of compact and light weight.

12 ton bottle jack & required lumber.

Grit dog wrote:
Like Matt said, measure the clearance axle to ground and subtract most of the tire section height to make sure it will fit if you get a flat.

You can also carry a couple of lengths of 2x6 and pull the flat tire up on to them to buy back some clearance.

Several options. I have successfully used the scissor type screw jacks from older pickups. I like those better than the newer compact owns that look like a bottle Jack.
Limit of maybe 2 tons tops on those though.
Other options, especially if you have torsion axles, have some blocks/drive up ramp to drive the good tire up on, reasing the flat. Have to go higher with leaf springs than torsion axles.
Bottle Jack or floor Jack is what I'd be thinking though. Compact 3 ton floor Jack if you have the room or the old standby 10t bottle Jack will safely lift most anything you need to lift with some sense and creativity.

Like Matt said, measure the clearance axle to ground and subtract most of the tire section height to make sure it will fit if you get a flat.

RobWNY wrote:
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.

That 1 inch contact has always worried me too. I've used every type of jack out there I think. Including the old bumper jack that you hoped wouldn't kick out and break your leg. Haven't they come up with an adapter (like a cradle) to drop over that 1 inch head on a bottle jack? That would make it much safer. Now, if there's not such a thing and you invent this, I want in on the millions you will make, and I'll trust you that you will let me know when and where I can pick up the money. By the way, I have a used bridge for sale cheap. I pick it up at a good price on the internet so will pass the savings on to you.

I carry multiple jacks between my car and my class A ranging from a 2 ton Floor Jack to a 12 ton Air/hydraulic jack-jack.

I will tell you of the issues

FLor jack goes under things the bottle jacks won't fit under.. But alas even it is a bit high for the car.. So I have to find an alternative point and jack it up a bit (unload springs some) then put a block (Big 4x4 thing I carry) than re-position then I can lift the axle to change the flat, and then let it down, first removing the block, the full tire gives enough clearance

on the RV it depends on what I'm doing, some things I have to use much the same procedure but with teh 12 ton jack, other things I can just use the 12 ton.

I like that jack-jack (The air operated pump is like a jack hammer) picks stuff up real easy.

Hi.. I have a 10 ton bottle jack which I have used to change flat tires. Work great and does not take much storage room in the trailer. Jim2007

A friend was killed when his jack slipped. Be careful out there.

Dr Quick wrote:
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.

+1 why purchase and carry a second jack when your truck already has one?

I carry a bottle jack, 10 ton??, and I also have a 6x6 that has an angle cut into it with a flat spot on the top that I put either in front or behind the good tire on that side. Simply drive or back onto it and the flat tire will be off the ground enough to change it out.