Multiquip EM502644 Jackshaft Key

The Multiquip EM502644 Jackshaft Key is a genuine OEM component designed for MQ Mixer series concrete mixers, including the MC12PH. As a direct OEM replacement sourced through Multiquip's authorized parts network, EM502644 is manufactured to the same specification as the original, ensuring a correct, confident installation with no guesswork on fitment. Keeping this small but critical drive component in good condition is essential to maintaining proper power transfer through the mixer's drivetrain.

Key Features

• Genuine OEM Drive Integrity — Manufactured to Multiquip's original specification, ensuring the key seats correctly in the jackshaft keyway and transmits torque without slippage or play.
• Direct Drop-In Installation — Dimensioned to fit the jackshaft and mating hub on MQ Mixer models, slotting into position without machining or modification.
• Confirmed Fitment for MQ Mixer Series — Verified for use on the MC12PH and compatible MQ Mixer series concrete mixing equipment.
• Positive Power Transmission — A correctly sized key locks the shaft and hub together as a single rotating unit, preventing the slipping and rotational lag that accelerates wear on both the shaft and driven components.
• Cost-Effective Maintenance Component — Replacing a worn or sheared key at the first sign of drive slippage protects far more expensive jackshaft and hub components from secondary damage.

The jackshaft key is a small rectangular metal piece that fits into matching slots — called keyways — cut into both the jackshaft and the hub of the component it drives. By locking the two together, the key ensures that rotational force from the engine transfers directly and positively to the drum drive system, with no relative movement between shaft and hub. When a key wears, deforms, or shears, the shaft spins independently of the driven component, causing the drum to lose power or stop turning entirely — and allowing the keyway itself to wallow out, turning a minor repair into a costlier one.

Part Details

Compatibility & Fitment

Verify Before You Order

Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.

Why Buy From DHS Equipment

Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.

Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.