I am relatively new to the tractor scene, having "inherited" an older model Massy 35 a while back. Worked great last season, but while I was using it for the first time this season(last week) the mower sounded as if I had hit rocks-no rocks. When I looked back, the place where the pto shaft goes into the gear box ,what appears to be a seal or cap for closing where the bearings are had come open, and I don't know how to fix it.Also, There is something that looks like metal rick-rack just inside the little slot that is open...what is this?