If the bearing you're referring to is the the bearing that supports a two piece drive shaft, here in Saskatchewan, Canada, we refer to it as a center bearing. I used to have to change these things on my '89 F250HD SC LB 4X4 like oil. Any mud + water and it would be shot, got really annoying at $50-60 a pop.

Never heard of it referred to as a swing bearing, so I may be way off base.

Waxy