my 1976 Fj40 gets a bad vibration while driving under power (not occuring while rolling or on trailing throttle) and usually over 50KM per hour (so thats around 30Miles per hour or something) i have a suspision it could be drive shaft related... just a hunch. how do i tell if my universal joints on my rear drive shaft are in phase with one another? how would i line them up if i separated the two piece shaft? is it possible that the uni joints could have become out of phase??? it may have something to do with last nights antics last night i was clowning around, playing with the fj, it was running sweet and i decided to climb a small concrete step up in 2wd, just to see if it would do it. the rear wheels spun for a second before hooking up and climbing the thing. it hooked up rather violently.