There's definitely an inner oil seal as well as an outer oil seal. The outer oil seal comes out with the axle assembly. The inner seal tends to stay in the axle housing. I checked out 1995, 1997 and 2001 on Kia Tech Info and it shows both seals for all three years. I've been getting some grinding noises lately and thought it was the left rear bearing. It was a little junked up, but seemed decent so I cleaned it out and used some synthetic wheel bearing grease on it. I do have to say that my inner oil seal did seem to have been leaking a little though.

Still haven't solved the grinding. Maybe it's the front...