I took the knob off my Corsair and used a hair dryer to heat up the PTO shaft and then wicked a little "penetrating oil with teflon"
between the concentric shafts and into the reduction drive. It works like a charm now.
TenTec PTO Rebuild Kit
You must tear down the entire PTO, clean the old grease off and resassemble it. It's a rather intricate job. You really should have the instruction sheet that comes with the $25 PTO rebuild kit. Their grease is ok but I used some thick silicon grease that seems smoother. Maybe the factory will fax you a copy of the instructions. Just be sure to allow plenty of room on the table to lay out the parts in some order.
Write down some notes about the wires you disconnect. Putting the dial plate back on is really tricky. I used a heavy thread to hold the hairpin open while I sneaked the beast back on the shaft.
You'll need it.