I found this on ebay - I am not sure if that would help make the repair. (It appears that this is the wrong diameter)Bringing this thread back to life compliments of the search engine....
Pic's tell the story:
Splines (18) worn smooth on the coupler that goes over the crank shaft protruding out the front of the L245DT.
Trying to find the replacement coupler (18 spline) and repair this one.
That one is really close....the inside diameter on the one I have is 1" and I see the JD one is just a bit over that.I found this on ebay - I am not sure if that would help make the repair. (It appears that this is the wrong diameter)
https://www.ebay.com/itm/John-Deere-Axle-Shaft-Coupler-Part-WN-H165510-4-Long-18-Spline-for-Combines-/253544361706