I grew up on a 1948 Oliver 70.  I can't help you with the bearings, but the worm gear of the steering front stem was very loose and worn, and reputed to be one of the hardest steering tractors around.  But it was a great tractor and I have many great memories with it.  I wished my dad had kept it, but in 1968 he gave it up.  Now he wishes he had kept it.  Hard to believe how much farming has changed.