Outer Limits 4x4 Board

I have a 93 4dr Vitara that makes a horrible noise/severe vibration at around 100kmh; it's far more noticeable when I back off the accelerator. I've recently replaced the rear diff (for a different reason), which i hoped might solve the vibration/noise as well, however it didn't and i still have the noise - it's nothing to do with the gearbox since it's not dependent on being in gear. Also, when the car is sitting on flat ground, there is some movement noticeable when pushing/pulling on the top of the front wheels.

So, the question is, are the bearings adjustable in any way or can they only be replaced, and how likely are front wheel bearings to generate severe vibration and noise?

i'd be looking at the rear tailshaft first. how much lift and how many k's?

Yeah, that's what i thought it was first too, so i checked the uni's and had one changed - still no difference to noise. The rear diff also needed changing due to backlash, which i'd hoped would fix the noise, but no luck with that either. I'm running out of ideas - what else would make such a noise/vibration and that also is louder when backing off? It does the same thing out of gear so really can't be anything else other than the bearings...
BTW, there's no lift at this stage and it has done 265k.

the front bearings are agjustable in that u can tighten them. what i had before when i bought my vit was there wasnt a seal in the hub and over time water got in and rusted/corroded the shaft thing that the bearing sits on so at full tightness it was still loose. got new shaft and bearing and loose wheel was fixed.