back and forth play in drive train of 1993 horse tines attachment?

[davennall]

Good morning all. Dave here. Trying to find out how much play there should be in this tiller attachment. Dont have the breakdown and parts manual.
It does everything but cut dirt. It slips on the pto dog. It has a good 1/4 inch of play in it. Did this suddenly. Been working correcy for 22 years and untold thousands of hours so i've never had to wlrk on it before. Any feedback will be greatly appreciated. Thanks in advance for any responses.