4WD FRONT RIGHT VIBRATION

[mikestrome]

I need help diagnosing my vibration problem on my 1992 mazda mpv 4wd. It started about 6,000 miles ago but it has become more of a problem since the day I rode passenger. The vibration you feel through the floor panel while sitting shotgun is double of what you feel when driving, kind of like an oscillation wer.. wer.. wer like standing on a razor. The feel you get when driving is mostly noise that gets louder and faster from zero to 45 then you start to feel the shimmy like a rock is stuck in the tire and your hand starts to shake, (sometimes I look up to see if there is a helicopter). two months ago I had new tires installed and balanced with no difference(I don't know if they rotated the rims) . Had my brakes done rotors turned in the last year. I considered changing my wheel bearing but after two hours trying to get the spindle nut off with no luck I gave up (tried a break bar with four foot snipe, tried a 200 lb impact no luck) , is the thread left?
Any suggestions?
Thanks. Mike.

[mikestrome]

I couldn't waite any longer. I took it in to Mazda dealership (believe it or not they were cheaper than most quotes I got from independent garages) and they diagnosed the problem to be the bearing. The total cost including bearing, bearing seals, transfercase seal, shop charges and taxes was $320.00 Canadian, about $200.00 us dollars. The parts alone if I had done it myself were $120.00 canadian bucks and that doesn't include gas, alignment and charges to have my hub/ bearing assy pressed off the stearing nuckle.
The van is verry quite and smooth now.