David G Oklahoma City , OK November 05, 2015 Appliance: KitchenAid 5-Speed Blender KSB5ER4 Kitchenaid Blender Ksb5er4: Coupler worn out. How to replace Blender Drive Coupler. I followed your instructions and it was fixed in a few minutes. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes