I have a Kitchen Aid mixer model KP50PSBU. It has 9 screws required to gain access to the motor and gears. That doesn't count the four large screws that hold the mixer to the stand and the one screw holding the rear cover. Your mixer may be different. After removing the stand, you should have access to two of the screws. There are two more in the middle of the mixer. The remaining five are underneath a metal collar which just slides off. Before you can remove these screws, you must use a punch or nail set to remove the pin on the main shaft. This should allow you to remove the shaft cover which will give you full access to the remaining five screws.
Be carefull when reassembling, their is an pin in the upper part of the main shaft which must catch the gear that it rides on.
Their are several gears. The plastic gear that fails most often is driven directly by the motor. It should be obvious.
I hope this helps.
Steve, December 2005
