To change the gears you need to get hold of the gear shaft with a pipe wrench or Vise Grip and then unscrew the gear.
The gear is screwed on and off like a regular bolt..it is not reversed.
White Mountain made two different diameter dashers for their 20 quart machines. Make sure you measure the square hole in the top gear or the top of the dasher.
The size should be 3/4 or 5/8 inch.
We are now making the top gear and shaft gear out of stainless steel.
Please note the price difference on the parts list.