4hi or 4 low? Either way you want to make sure your rolling so that the gears can line up, basically. You can put it into 4hi up to 50 mph, and 4lo basically a crawl, like under 5mph I'm pretty sure. No 4lo on road, and try to only use 4hi when its slick conditions i.e. snow/slush. I'm sure someone can elaborate 10x better than me but thats the basics.
Poverty/College Budget 2004 TJ 2.5" RC coils, 1.25" BL, M95 shocks 4.5" up 4.75" down travel front, 4.7" up, 5.3" down rear
Live around Philly or south Jersey? Come wheeling or wrenching! Look in here \/\/\/