The Multiquip 21570 Woodruff Key #406 1/8" x 3/4" is a genuine OEM Woodruff Key designed for the HHN34TVD ride-on power trowel and MQD2H, MQD3H, MQD2HA, and MQD3HA diaphragm pump models. As a factory-sourced component, it delivers the exact dimensions and material spec required for proper shaft-to-hub alignment in these machines. DHS Equipment supplies this part direct, so you can be confident you're ordering the correct piece for your equipment. Verify your model code against the fitment list before ordering to ensure a correct match.
Key Features
- Genuine OEM Dimensional Accuracy — Manufactured to Multiquip's exact #406 profile at 1/8" x 3/4", ensuring the key seats fully and holds torque transfer without slop or rocking.
- Drop-In Shaft Replacement — Machined to the standard Woodruff key slot profile, this part installs directly into the existing keyway with no filing or shimming required.
- Broad Multiquip Fitment — Compatible with the HHN34TVD ride-on power trowel and MQD2H, MQD3H, MQD2HA, and MQD3HA diaphragm pumps, covering both trowel and pump applications in the Multiquip lineup.
- Shaft-to-Hub Lock Integrity — A correctly sized Woodruff key prevents rotational slippage between the shaft and mounted component, maintaining full power transfer and protecting both mating surfaces from wear damage.
- Drive Safety in Pump and Trowel Applications — In diaphragm pump and power trowel drive systems, a worn or undersized key can allow the driven component to slip under load — using the correct OEM key eliminates that risk.
A Woodruff key is a small, semi-circular metal key that fits into a matching slot milled into a shaft, locking a gear, pulley, or hub in place so that rotational force is transferred cleanly from the shaft to the mounted component. Without it, or with a worn or incorrect key, the driven component can spin freely on the shaft, causing lost power, accelerated wear on the keyway, and potential damage to surrounding drive components. Replacing a worn Woodruff key promptly is one of the lowest-cost ways to protect a much more expensive shaft or hub assembly.
Part Details
| Part Number | 21570 |
|---|---|
| Brand | Multiquip |
| Part Type | Genuine OEM |
| Description | Woodruff Key #406 1/8" x 3/4" |
Compatibility & Fitment
| Name | Model |
|---|---|
| Whiteman Ride-On Power Trowels | HHN34TVD |
| Diaphragm Pumps | MQD2H |
| Diaphragm Pumps | MQD3H |
| Diaphragm Pumps | MQD2HA |
| Diaphragm Pumps | MQD3HA |
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.
