Well I would tend to agree with both of you that the mower is the problem after checking everything on the tractor and finding no issues, but I cant figure out what is going on there as everything seems normal also. I do not think I am overloading it, and if I am I would be surprised because I am not working it any harder than my lawn mower. I am running in 4th gear, which if I had to go any slower, I might as well get the riding mower back out. I dont know if all finish mowers are created equal on how they are built, but mine has about a 1 to 6 ratio, pto to blade speed, turning about 3200-3300 rpm. So assuming that I am not overworking it, that only leaves that the mower is taking more torque than necessary to turn it and since I have replaced all the bearings, nothing is left but the gearbox, but how likely is that? I would say pretty unlikely but I will check it out closer.