4wd front U-joints binding, dry, clacking, causing wheel jerk? , try this; (It works). 1. Go to an empty parking lot with a full can of penetrating oil, turn your wheels to lock, spray joints, go in a circle spray etc etc etc, change directions repeat, repeat, repeat. or 2. Tear a 1' strip of old towel 1" wide, soak it in ATF, run them through you joints and tie the ends so they don't come out and drive like that for a couple days and start by making some tight turns.

My joints were creaking, jerking the wheel big time, etc, 2 years ago and after rejuvenating them with this fix (just took the first one but was slightly better after fix # 2) they have been like new ever since.