1900 pto clutch

[Metric Fords]

My pto turns when free but will not when attached to mower. This came on all the sudden.
I read about clutch’s not releasing but this is different. It goes in to pto engage with no problem and turns when free.
The bolts under the rubber cover all have about have a little clearance. Can they have too much?

 

[Sean in PA]

Is the gearbox on the mower stuck?

 

[Metric Fords]

No it’s not. I take shaft off and I can hold tractor pto with hand when engaged

 

[Metric Fords]

1803mm on the clearance

 

[Metric Fords]

Hello, found problem. One way pto clutch is coming apart.
Where do I get another one?
Thanks