21581531 Hub | Genuine Volvo Penta Part

🔧 Product Description

A genuine heavy-duty hub used in the engine-to-reverse-gear connecting components on Volvo Penta D11A-A marine propulsion installations with ZF325A-E or ZF325-1A transmissions. It forms part of the torque-transfer and alignment arrangement between the flexible coupling and reversing gear.

🚤 Compatibility

Typically suits:

• Volvo Penta D13C1-A MP
• Volvo Penta D12C-A MP
• Volvo Penta D12D-A MP
• Volvo Penta D12D-B MP
• Volvo Penta D12D-C MP
• Volvo Penta D12D-D MP
• Volvo Penta D12D-E MP
• Volvo Penta D12D-F MP
• Volvo Penta D12D-G MP
• Volvo Penta D12D-H MP
• Volvo Penta D13B-B MP
• Volvo Penta D11B3-A MP
• Volvo Penta D11A-A
• Volvo Penta D11A-B
• Volvo Penta D11A-C
• Volvo Penta D11A-E
• Volvo Penta D11A-D MP
• Volvo Penta D11B1-A MP

• Engine Family: D
• HP Range: Approximately 625-725 HP
• Year Range: Approximately 2007 - 2015

⚙️ Key Features

• Genuine Volvo Penta driveline connection hub
• Used with ZF325A-E and ZF325-1A reverse gears
• Precision-machined pilot, spline and mounting surfaces
• Designed for high-output D11 marine propulsion loads
• Direct replacement for the exact catalogued hub
• Engine type: 10.8L inline six-cylinder turbocharged marine diesel with ZF reverse gear

🔌 Function

Transfers engine torque into the reverse gear while maintaining concentric alignment between the flywheel-side coupling and transmission input.

⚠️ Common Signs of Failure

• Driveline vibration under load
• Fretting or movement at the hub mounting faces
• Spline or pilot wear
• Loose fasteners or coupling noise
• Misalignment causing premature coupling or bearing wear

🛠️ Service Notes

• Get the hub off with the correct puller rather than levering or hammering it; a hub driven off or on is enough to damage the shaft, the bearing behind it and the hub itself
• Clean and inspect the shaft, keyway or taper and check for scoring, wear steps and fretting; a hub will not run true on a damaged seat and the fault will come straight back
• Inspect and renew the seal that runs on or behind the hub while access is good, and check the sealing surface for a wear groove
• Draw the hub on square, fully home to the position the workshop manual for your engine gives, and tighten the retaining fastener to the manual figure with any specified locking method
• Check the drive belt alignment and run-out after fitting, then run the engine and watch for wobble, noise or a belt tracking off to one side

🔄 Supersession & Cross Reference

OEM / Related Numbers

• 3848150 - related reversing-gear assemblies
• 3848151 - related reversing-gear assemblies
• 3848152 - related reversing-gear assemblies
• 21509619 - roller kit
• 3589507 - companion flange
• 3808128 - engine anchorage
• 21532583 - flexible coupling
• 995056 - spacer
• 21588215 - control valve

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging