Difficult to engage PTO

Hi,

I notice on my 7745 that the PTO has become more and more difficult to engage. I make sure I have the hand lever for the PTO clutch all the way up, yet I get an awfull lot of resistance and grinding noise as I try to engage the lever. I find if I reduce the engine revs to the point where the tractor almost cuts out I can then engage the PTO.
Could this be an issue of adjusting the cable of the hand clutch, or could it be something else?

Thanks

Rujib

try adjusting cable, no help, then remove inspection plate on bell housing, have someone to lift lever to see if large throw out bearing, outer forks move. if they dont then the clutch fork shaft is broken. this happened on my 6245. had to replace lever fork that slides over main fork clutch shaft