Robert K Colgate , WI August 07, 2022 Appliance: KitchenAid 5-Speed Blender KSB5ER4 Kitchenaid Blender Ksb5er4: 20 year old drive coupler crumbled/failed. How to replace Blender Drive Coupler. Pried off remaining aluminum disk and cleaned off the shaft's left hand treads. Fully screwed on the new drive coupler, not tight, mounted pitcher and turned on blender to snug down the coupler. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes