The reason I picked the Hi-Lift brand is because they're waranteed, rebuildable, and even kits with different components that you can add to your jack to make those jobs safer. You definitely should not be jacking your vehicle up by a rock slider with a Hi-Lift jack and changing two wheels and tires at a time... but as long as you realize it's super dangerous, I'm not going to preach to you. I just hope you're using jack stands too.

I've even seen and heard of people using the jack handle on the Hi-Lift's as tie rods when in a pinch trying to limp home.

Again, $65 shipped from Summit... Hi-Lift.. of the 48" flavor. Any bigger would be unnecessary for a Jeep IMO.