Hello, I have somewhat of an oddball tractor. It is a 1979 SAME Delfino 35, which is a 35hp 2 cyl diesel tractor. I am having a problem with the PTO staying engaged. I have pulled the pto shaft out numerious to check it and the last time replaced the bearing had it straightened (had a small deflection in it) but when I put it in gear it will start to rotate for a while (with bush hog attached) and then it will throw the PTO out of gear. You cannot hold it in and if you try you will have a sprained thumb. I have of course checked the engaging collar and the splines and they appear to be ok. What am I missing here. Any of you tractor gurus have any clues that might help me solve this problem.