I have recently changed the front inside and outside wheel bearings, races, and seals on my 91 p/u a week later they began making a rubbing/grinding noise with the rotation of the wheel. Followed the Chilton's repair manual for the replacement of the bearings. What could be causing this?

 

Have you checked your brakes? Are you sure its the wheel bearings?

 

should have mentioned that I changed the rotors and pads as well

 

if it is really the wheel bearings making noise, I'd question the installation of the bearing races.

 

It could be the pads dragging on the rotor.

Doesn't matter if the rotors and pads are new if the calipers are dragging.