Slipper clutch burnt out! Why?!

[heinzeman]

Hi all.

My CAT sX made a bad sound on short grass the other day. On inspection, removed the spur gear, and found that the hole in the centre of the spur that mounts on the layshaft had melted, which allowed the spur to move about so it was not spinning true.

It was the standard 83T. I have now replaced it with an 82T. I have kept my pinion the same, which is a 22T.

Does anyone know what caused this melting and what I can do to prevent it happening again?

I had tightened the locknut on the end of the layshaft as per the manual I.e flush with the end of the layshaft.

Please help!!!