My ice cube tray fills and freezes just fine but it won't drop the ice cubes until I jiggle the on off arm up and down and then it will drop the ice cubes and fill and freeze again but I have to do the same each time to get it to dump.

You need to pull off the cover on the end of the ice maker where you will see a little microswitch that works with the arm. When the thermostat at the bottom calls for it to harvest it energizes a heater and starts the motor to harvest ice and when the cam rotates it raises the arm and then lets it drop. It has a spring on the arm which could be stretched out or it could have come loose, or the microswitch may need an adjustment which can be done by loosening the mounting screws and moving it (unplug first). You can even have a defective switch, but that would be low on my list of causes. Here is a manual on it: https://dl.dropboxusercontent.com/u/8010163/R-106%20Whirlpool%20Icemaker%20Troubleshooting%20Ser vice%20Manual.pdf
All of these icemakers are made by one or two companies and are almost identical.