I finally got most of the little things done on the tractor and I mowed for about 7 hours yesterday. When I finished, I parked it on the concrete. I came back a little while later, and several capfulls of oil had dripped out of the bellhousing. I believe I have a mid-70's 20C, but I'm not certain. Did all of the 3 cylinder Perkins diesels have the same rear main seal back then, or do I need to know exactly what tractor I have? You just break the tractor apart, remove the clutch and flywheel, pull the seal housing, replace the seal, then put it all back together, right? I've done a bunch of automotive clutches over the years. I hope I can tackle a tractor.