Item was sent promptly. Beware that you must have a vise to hold unit still. A screwdriver is needed to hold the screw on bottom of machine still while turning the inside collar nut to remove, Vise grip pliers are needed to grab the collar nut to ensure good holding of nut.. Remember the nut is REVERSE threaded so turn clockwise to unscrew. And turn counter clockwise to put back on. My plastic piece of gear was broken off so nut was easy to access. Once I did this it came off easily. I did use some oil to help loosen the nut and it sat for one day before I started. Otherwise everything went smoothly.