An E60 can be a load for a tractor on nearly 70hp never mind one of around 40.
But seriously, Dotty had developed the common Dexta trend of the PTO jumping out of gear. I found that she had a lot of fore and aft movement on the PTO shaft that needed investigation.
On removing the shaft I found that the whole circlip, circlip groove and end of the bearing housing were missing allowing the bearing to float at will.
This damage has been caused by having a PTO shaft on an implement that has "Bottomed Out" either when being used on the lift arms or by turning. The PTO shaft has been forced back and the bearing has broken the housing.
Please check the length of ALL Pto shafts in all positions before fitting them on to your tractors to avoid similar damage.
I got a replacement housing from my local s/h dealer and now Dotty's PTO no longer jumps out of gear.