Oh. Scrubbing the tires in 4wd won't do any damage for short periods of time. It's prolonged driving on the highway the puts the driveline under constant stress. If doing what you did caused problems, every 4wd truck would be in the repair shop. It is much more likely the universal joint didn't want to be a universal joint any longer and was already thinking about failing. At some point, water gets into the cups and rust them and the needle bearings. The grinding action leads to one of the cups cracking apart. Due to its design, it can't actually fall apart, but it can cause lots of noise and a horrendous vibration. I suspect the little added stress of hauling wood was just what it needed to break. The problem would have occurred anyhow, just not at that moment.
A different problem these joints can cause is if one of the cups becomes tight from rusted or broken needle bearings, it will force a turned steering wheel back straight ahead every half tire revolution. That can be a weird sensation if you've never felt it before.
Thursday, June 17th, 2010 AT 9:21 PM