9704230 Blender Drive Coupler with Spanner Kit

Reinforced Rubber Composition: Manufactured from a high-density, impact-resistant rubber compound designed to provide maximum grip for the blender jar while protecting the motor from torque spikes.
Precision Threaded Metal Core: Features a high-strength zinc or steel internal thread that ensures a secure, wobble-free connection to the blender's motor drive shaft.
Sacrificial Safety Design: Specifically engineered to "shear" or strip if the blender blades become jammed (e.g., by ice or frozen fruit), acting as a mechanical fuse to prevent expensive motor burnout.
Included Spanner Wrench: Comes with a specialized thin-profile wrench designed to fit the narrow gap between the coupler and the blender base, allowing for easy removal without disassembling the entire unit.
6-Prong Engagement: Features the standard 6-tab design that ensures 360-degree power transfer to the blender blade assembly for smooth, consistent blending performance.

This drive coupler is the primary replacement part for KitchenAid's classic 5-speed and 3-speed blender lines. Key compatible models include:

KitchenAid KSB5 Series: KSB5, KSB5WH, KSB5AC, KSB5BK, KSB5ER, KSB5GN, KSB5GR.
KitchenAid KSB3 Series: KSB3, KSB3WH, KSB3AC.
Other Models: Fits many 4KSB5 series and Ultra Power blender models.
Note: Not compatible with the newer KitchenAid "Diamond" or "K400" blender series which use a different coupling system.

Rounded or Stripped Prongs: The 6 rubber tabs are visibly worn down or smooth, causing the motor to spin while the blades remain stationary.
Burning Rubber Smell: A distinct odor during blending, indicating the coupler is slipping against the jar base and generating excessive friction heat.
Black Rubber Dust: You notice small black flecks or shavings appearing on the blender base beneath the jar.
Loud Grinding Noise: A harsh mechanical sound during operation, suggesting the metal threads are loose or the rubber has separated from the core.
Visible Cracks: The rubber head shows deep fractures or chunks missing, leading to an unbalanced and vibrating blender jar.

Reverse Threads Warning: This part is Left-Hand Threaded. To loosen the old coupler, you must turn it Clockwise. To tighten the new one, turn it Counter-Clockwise.
The Wrench Technique: Slide the included spanner wrench under the coupler to hold the motor shaft steady. If the old coupler is stuck, you may need to carefully use a flat-head screwdriver to pry up while turning.
Cleaning the Shaft: Before installing the new coupler, wipe the motor shaft threads with a damp cloth to remove any old rubber debris or sticky food residue.
Hand Tighten Only: Screw the new coupler on by hand. The natural rotation of the blender motor will further tighten the coupler during its first use.
Check the Blade: While the jar is off, inspect the underside of your blender blade assembly. If the metal gear on the jar is also worn, it will rapidly destroy your brand-new rubber coupler.

Blender Parts