Found a bolt not sure where it goes

[StarTech]

Using your image, that is a 5/16 bolt.

The 5/16 that is that long used on the mower is the one at the PTO clutch.
Anti-rotation bolt that keeps the clutch from spinning.

 

[Molon labe]

Using your image, that is a 5/16 bolt.
View attachment 69095
The 5/16 that is that long used on the mower is the one at the PTO clutch.
Anti-rotation bolt that keeps the clutch from spinning.

Star tech you were precisely right that was what it was I think you very much!