Yes, I agree that would have been the reason. I have had clutch slip on my mower before but would never go to that extreme. As you know you won't be able to stop the reel from spinning. I have two kids so a spinning reel poses a safety risk when you take the catcher off.

Thanks for explaning all that. I have replaced the cork pad before so I am familiar with the setup.

The bearing on the shaft, I believe this is the only "non sealed" bearing on the entire mower. I can shake the bearing and you can feel and hear the ball bearings move. I'm not sure if this is normal and if I need to oil it or if you can buy a sealed bearing like the others, eg on the reel ends. Would you know?