Better trailer jack/wheel for tounge extension.
I'm in the same boat as the posts above (no pun intended

). I'll need an extension and I think the best way to go is a square tube extension into the hitch receiver, but obviously as it has been pointed out that puts a heck of a lot of stress over a long length of unsupported tube. Ergo, the suggestion is to use the trailer jack/wheel to support the tongue weight... but those cheesy plastic wheels don't hold up well to anything except light rolling around on really clean, level surfaces.
My plan is this, I'll make my hitch mount extension, probably 8 feet, from heavy wall tube. I'll end up using the trailer jack/wheel to support so it needs an upgrade. Two ways to do this;
1. Just buy a new trailer jack. Fulton has some heavier duty trailer jacks that have heavy duty single wheels or two wheels. They swivel too, which is better than having to kick the darn thing around all the time! These Fulton jacks get pricey!
2. Just upgrade the wheel. Unfortunately the most common jacks that we all have are similar versions, the wheel is welded to the jack shaft. You'll have to cut the old one off and weld on a plate to get a new one. I'm a welder and have my own equipment at home so this isn't a big deal for me, but I know it is for others.
I get my caster wheels from an Industrial Overstock place in San Diego called K-Surplus, its like heaven for the DIYers. My Toy-hauler has an electric jack that came with a skid, no wheel. I got a heavy duty ball bearing caster with a poly wheel rated for 1/2 ton, luckily it was a bolt on application. It makes swinging the tongue on that trailer a breeze, plus the wheel is bomb proof.