Multiquip 21812 Gearbox Housing Machined HHN

The Multiquip 21812 is a genuine OEM Gearbox Housing Machined HHN designed for Whiteman HHN and HHX series ride-on power trowels, including the HHN31V, HHN34TVD, HHXD5, HHXG5, HHXD5-ES, HHXDF4-DF5, and HHNG5. As a direct Multiquip OEM component, part 21812 is manufactured to the exact tolerances and specifications of the original housing, ensuring correct gear alignment and proper load transfer within the trowel's gearbox assembly. Sourced through DHS Equipment as an authorized Multiquip parts distributor, you can be confident this is the right part for your machine.

Key Features

• Genuine OEM Machined Housing: — Cast and precision-machined to original Multiquip specifications, maintaining the exact bore tolerances required for proper gear mesh and bearing seating in the HHN gearbox.
• Direct-Fit Replacement: — Matches the original mounting bolt pattern and internal geometry of the HHN series gearbox, allowing straightforward installation without reworking mating components.
• Broad HHN and HHX Series Fitment: — Compatible with HHN31V, HHN34TVD, HHXD5, HHXG5, HHXD5-ES, HHXDF4-DF5, and HHNG5 Whiteman ride-on power trowels.
• Blade Drive Integrity: — A structurally sound gearbox housing keeps the trowel's blade rotation consistent and true; a cracked or worn housing allows gear misalignment that accelerates bearing failure and degrades finish quality.
• Operator Safety Relevance: — A compromised gearbox housing on a ride-on trowel can lead to sudden drivetrain failure under load — replacing a damaged housing promptly maintains safe, controlled blade operation.

The gearbox housing is the structural core of the trowel's blade drive system, enclosing the gears and bearings that transfer engine power to the finishing blades. It holds all internal drivetrain components in precise alignment so that torque is transmitted smoothly and blade pitch can be adjusted accurately. When the housing becomes cracked, worn at the bearing bores, or damaged, gear alignment is lost — leading to accelerated internal wear, abnormal vibration, inconsistent blade speed, and ultimately drivetrain failure mid-pour.

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.