What size jack ?

I carry this jack in our Class C motorhome:

http://www.amazon.com/Torin-2-Stage-Hydraulic-Bottle-Jack/dp/B00028FB8Q

I like "overkill" lifting capacity, thinking that a higher capacity jack may stay leak-free and hence more reliable, longer. Also note that the jack in my link has a 2-Stage lifting range ... but still not tall when fully retracted for placement under low lift points on your vehicle. The increased lifting range means that it can lift higher, so that in soft ground it's base can sink deeper into the ground (even with a footing board under it) and still lift. Higher lift also means that perhaps in some situations the jack could be used on the RV's frame instead of only on it's rear axle or front/rear spring mounts.

I can use our 2X6 wooden step leveling assemblies for jack footing in very soft stuff, if ever needed.

Get at least a 12 ton, it is better to have too much jack than something that is marginal. My first jack was an 8 ton which should have been able to pickup a corner of our 8 ton mh, but it wouldn't. So for our second jack I got a 20 ton and have not regretted it.

i have a 12T HF jack that I got on sale for $10 since it was a display out of box one. Anyhow not only should you need a jack but I also carry the 120V electric impact for the wheel lugs. The lugs have a pretty good torque on them and ya really dont want to be shaking the rig to loosen or tighten on the jack. So the electric lug wrench is the answer for me. Also as recommended a solid piece of a minimum of 3/4 plywood, not particle board to jack on. Also if you carry leveling boards if a rear tire is out you can run the good tire up on one of the leveling boards to help lift the rear. Front wheels are totally different and so you will need a short jack to get under to jack up. The rig has roadside service but I may not want to sit for hours waiting for help thus the jack and stuff. also the spare is underneath and needs pressure on it to release tension on the security nut holding everything in place! HF sell these lug wrenches many times for around $50 and another $20 or less for the lug sockets. Now out towd does not have a spare so its going to be interesting to get a fix on that. Guess I will get a 'spare' for it plus a jack and a jack handle and........ Guess they think new tires dont go flat or you never leave city limits anymore?

Thanks !

I use a 3 ton no name jack that is at least 40 years old. I made a 4 foot jack handle so I can pump jack without crawling underneath.

I used to use a 6 ton with my E450 C and it IMO was barely adequate. The rear axle of your rig is over 9000 pounds loaded and when you jack you are lifting well inboard of the tires. So, you are lifting more than 1/2 of the weight of the rear axle. In theory a 6 ton jack should nearly lift the entire rig, but from my experience, the cheap "Harbor Freight" type jacks are good for about half their rated capacity. If I were to do it again I would buy at least an 8-10 ton jack.

Figure you will have less than 4,000 pounds at any wheel. So a 4 ton jack would be over double that. I know many carry 8 to 12 ton bottle jacks (including myself) but that is obviously an overkill.

A four-ton hydraulic bottle jack will lift one corner of a Class C. The problem is that we're in an awkward position under there and it's very hard to pump the handle hard enough.
I have a 12-ton, old American-Made Blackhawk that I just love. Very easy to lift the coach from "down under." But it's heavy and awkward to position.

My MVP package turned out to be a 10-ton Harbor Fright bottle jack and an old but very rugged 4-ton small steel jack stand. I had a brake problem out of town and found I could just fit the 10-ton and the jack stand in the space between shock absorber mount, spring, and tire on he passenger side. Passenger side's tighter than driver side, at least for me because the track bar mounts there.

I just looked the HF site and it seems they have only 8- and 12-ton right now. 10's no longer in the product line. They offer 12-ton in a low-profile version and that would intrigue me. Remember, coach is a few inches lower on a flat than an inflated tire. Kinda Captain Obvious remark, but keep it in mind.

You also need something to stabilize jack and stand on soft ground. I've found where anything "two-by" was too thick. Thinking 3/4" plywood a foot and something square or even 12" * 18" might be the best single pad. I think it's good to have both jack and jack stand on the same support piece.

I use a 12 ton hydraulic bottle jack. Make sure you have something to set the jack on if using it on soft surface and also wheel chocks. It's always safest to use a jack stand once the vehicle is jacked up. Hydraulic jacks can fail.