Product review (5 stars): A tight but perfect fit!
Perfect fit. It came in a box from Whirlpool so I am pretty sure it is an OEM part. I accidentally broke the old fan while I was vacuuming the cat hair out of the back of the fridge (there was enough hair in there to build a spare cat). The fan is held on the shaft by friction (no clips or anything) so with a little effort I slid the old one off the motor shaft. I was having trouble getting the new one to slide on so I lubed up the hole where the shaft goes with a little soap and water and then it slid right on (the hole through the center of the fan goes all the way through so the excess water will evaporate in no time flat).