NDDan
Guest
I'd check behind PTO flex coupling to see it hasn't built up uneven with dirt. Clutch pulley on mainshaft can also do this. I think vibration dampners can be checked somewhere but I've always just replaced. Bad viscous dampners on the old Allis would cause air conditioner belts to fly off all the time. Haven't replaced any Cummins dampners. Might be getting time for a tune up.