heres an update guys, i tried the mower this morning on my tractor, and there seemed to be a big improvment. the blades and mounts were all good when i had them checked at the dealer, all the shafts seemed to turn true, and u joints in pto yoke and bearings were fine. like i said in the previous post, the only thing we could find wrong was the stump jumper pan was a little loose, and we retightened the bolts. I used it this morning, and the vibration was considerably less than what it was, at least, acceptable i think. guess i will keep using it through the summer, and see how it goes. this is a great site, with a bunch of great guys, who are really great about sharing their knowledge and experience, and i for one, think it is fantastic. This is the first tractor i have ever owned, and this site and the guys who visit it, have been a tremendous help to a newbie, like myself, and my hat is off to you guys. thanks again