I just bought a '98 Forester which has a vibration when under load. Mechanic said I have frozen u joints and the prop shaft has to be replaced ($1100) because they are non-serviceable. I really hate being told what can't be done and I'm a cheap-skate, so I did a little searching and came up with http://rockforddriveline.com/replacem.htm. These guys have a whole line of u joints for "non-serviceable" drive shafts. I ordered three u joints for $110 and will replace them and test drive it. If I don't update this topic, it means all went well. Otherwise I will warn of the pitfalls. I would love to hear if anyone else has attempted this and what their success was.