I was pulling a small trailer up a hill the other day when I noticed a rattle started coming from under the machine, it a JD D155 with ~ 30 hours on it. It doesn't have the mower deck mounted but the rattle is coming from the PTO clutch, there is a notch that sits on a arm and the clutch is vibrating on the arm. I pulled the clutch off and all the bearings seem to be good but I can't for the life of me figure out what is causing it to vibrate so bad. Its definitely not right though.
The deck belt may act as a vibration dampener for the clutch so without the deck belt there is nothing to absorb the vibration therefore you are hearing the clutch rattle.
Shove a bit of old inner tube in there to take up the slack.
The pulley should not be turning with the PTO turned off.
If it is then there is a problem with the clutch or the wiring to the clutch.
If you do not mow the take the clutch right off and replace the bolt with a shorter one.
On some set ups you need to make up a spacer.
I do it regularly for customers who have trashed decks , but want to keep the mower for towing.
A short length of 1" gal water pipe and a very heavy washer under the bolt.
