Im not here to knock the blower just give a little information. The blower uses a part called a wear collar. It goes around the shaft and rubs against the lip seal. The lip seal is what keeps the oil in. On the inside of the wear collar is a very thin viton o-ring. It locks the collar to the shaft and keeps the oil in. The o-ring in my case failed at aprox. 2800 hrs. Its a simple repair and should be done as a maintenance item when you change the belts. I didn't occur any down time just a mess from the leaking oil. The dealer doesn't carry the parts and it was a scramble to find them. I do have the guys name and number and will try to remember to post them. I would suggest keeping the 7 dollar part on hand.