Originally Posted by JonnyBoy

I'll add something here...I haven't driven my first gen very much yet, still fixing issues as they come up. However, when I first bought it the gearing was still stock, 4.10's, and it had 35x12.5's on it. It could move just as good in 4hi as it could in 2hi. I think there may be something else going on here, like mismatched gears or something. A buddy of mine bought a rig without knowing it's history and it wouldn't even crawl at idle in 4lo, turns out somebody had geared it to 5.29's, but we suspect somebody blew up the rear diff and just put a 4.10 open diff in to get it driveable. So unless he was on pretty loose dirt, the 5.29 front/4.10 rear setup would bind enough to kill the motor. I think you should research a little bit and try the tire rotation method somebody suggested above and see if your current gears match.