92 toyota 4x4 steering knuckle vibration

Greetings! I am hoping that someone else has either heard of or fixed a
problem like this: When I got my truck a couple of months ago, it had a
semi-constant grinding noise that I assumed was the front left wheel
bearing. The noise got a little worse a week or two later so I pulled
the hub and replaced the bearings and the inner seal. This didn't help
much so I immediately repeated the procedure to insure that everything
was at the proper torque. This didn't help either and the
noise/vibration stepped up to something akin to having a concrete
vibrator strapped to the floor board. A friend suggested that it might
be the brass bushings in the knuckle (where the spline shaft comes
through) so I sprayed some lube into those and it worked like a charm
until the lube wore off. The problem now is that the lube is wearing
off faster and faster and the vibrating is getting worse, very quickly.
My question is this: Should I replace the brass bushings? Or is this
more likely a CV joint problem? The dust seal on the back of the
steering knuckle is almost completely gone. Will replacing this
magically fix all?