Are the blades swinging freely on the stump jumper? Usually after hitting something the blades will be pushed back and will wobble until you speed it up or slow it down until they straighten out to balance out. I'll usually idle the tractor down with the pto engaged, disengage the pto, set engine speed to 540 pto speed and slowly let out the clutch to quickly bring the cutter up to speed and the vibration is gone.I'm going to start with the blades. I don't have another shaft. The shaft still goes together real smooth.What could be wrong with the tractor to cause this. The PTO stub looks fine?
I have a shear pin on my cutter and have stalled my tractor several times without breaking the grade 2 shear pin.