-The auger housing is slightly warped so sometimes when hitting crud, the auger slips out of the bearings on the side of the housing. Just turn it off and pop it back in. Better would be to remove the auger and flex the sides of the housing in slightly, so the bearings hold the auger more tightly.
-It's in storage, so I just pulled these photos off the Internet. The item for sale is nearly identical to these, but has a bit more rust and nicer skid shoes.