jamas-
there are main seals in both axles, its what seals between the pumpkin and the gearing housing. Not difficult to replace, and just keep an eye on your diff fluid and your fine to drive it (if its the seal on the axle)....
Thanks alot for that. Makes me feel better about driving it 30 miles to the isuzu shop tonight. Sure hope the price tag stays relatively low for the repair. I would do it myself, but I am not that confident with my mechanical abilities.