We removed the plastic cap, E-ring and washer. The wheel slides forward but gets caught on the end of the axle, past the E-ring groove. The end of the axle seems to be flared to a larger diameter than the rest of the axle. Both front wheels have the problem. We do not see this situation on various youtube videos and it is not obvious to us how it could have come about in normal use. Our L100 tractor dates back to 2005. Suggestions would be appreciated.