Description

The Sherwood 09959K Impeller Kit is a complete raw water pump service kit designed for Sherwood pump systems used in marine engine cooling applications. This kit includes a precision-molded neoprene impeller along with multiple gaskets and an O-ring to ensure proper sealing and reliable water flow.

Built with a marine-grade neoprene impeller and a brass hub with a keyed drive, this kit delivers excellent durability and performance in both freshwater and saltwater environments. Replacing a worn impeller helps restore cooling efficiency, prevent overheating, and protect critical engine components.

This is a very common Sherwood impeller for gasoline inboards and light diesel applications, especially in PCM, Crusader, and Chrysler marine engines.

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Key Features

• Genuine Sherwood impeller service kit
• Marine-grade neoprene rubber construction
• 12-blade flexible impeller design
• Brass hub with 5/8″ keyed shaft (3/16″ keyway)
• Includes multiple gaskets and O-ring
• OEM-spec fit and performance

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Engine Compatibility

PCM (Pleasurecraft Marine)

• GM 5.0L / 5.7L / 8.1L
• Ford-based PCM engines (belt-driven pumps)
• Pre-2004 crank-driven systems (non-serpentine)

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Crusader Marine Engines

• Interceptor series
• GM-based V6 & V8 engines

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Chrysler Marine Engines

• 318 / 340 / 360
• 383 / 413 / 440

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Chris-Craft Marine Engines

• Model 350 and various classic V8 platforms

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Gray Marine Engines

• Fireball V8
• Compact V8 and 6-cylinder engines

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Perkins Diesel Engines

• 4-108
• 4-154

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Onan Marine Generators

• Diesel and gasoline generator sets using Sherwood pumps

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Universal / Westerbeke

• Light plant and marine diesel applications

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OMC / Volvo Penta (Pump-Based Fitment)

• Select 4, 6, and 8-cylinder engines using Sherwood pumps

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Sherwood Pump Compatibility (Primary Fitment)

Fits a wide range of Sherwood pumps, including:

A03, A16
B06
D55*, D60**, D65**, D75**
F15, F85
G1, G2, G15, G20, G21, G22
G30-2, G30-2B, G65, G95-1
G9901, G9902, G9903
H5, H10
J70, J90
K75, K75B
L9920G, L9930G
M10065G, M10180G, M10210G, M10263G, M10264G, M10270G, M10280G
N10390G**, N10410G, N10460, N10470, N10510G
P10550G*, P10560G**, P10610G, P10650G, P10700G, P10710G**
Q10755G, Q10765G, Q10770G, Q10855G**
R50G, R991, R10870G, R10920G, R10925G, R10930G, R10935G**, R10955G
RPGC

* Some pumps use 09959K + 10615K combo
** Some pumps use dual 09959K impellers

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Serial Number Fitment Notice

Fitment depends on:

• Pump model
• Shaft size (5/8″ keyed shaft required)
• Engine application

Always confirm compatibility using your pump model or engine serial number before ordering.

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Impeller Specifications (Fitment Critical)

• Diameter: 2-7/16″ (61–62 mm)
• Width: 1-1/4″ (31–32 mm)
• Shaft: 5/8″ keyed
• Keyway: 3/16″
• Blade Count: 12 blades
• Material: Neoprene rubber with metal hub

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What’s Included in the Kit

• Impeller
• O-ring
• Multiple gaskets (varies by kit version)

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When This Part Needs Replacement

Replace the impeller if you notice:

• Reduced or no cooling water flow
• Engine overheating
• Cracked, missing, or stiff vanes
• Reduced performance under load

Recommended service interval: every 100 hours or annually

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Installation Notes

• Lubricate impeller before installation
• Install with correct vane direction
• Ensure key is properly seated
• Replace all included gaskets and O-rings
• Inspect pump housing and wear plate

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Alternate / Superseded Part Numbers

OEM Cross References

• Sherwood: 09959K
• Replaces: 09959, 10685, 10687, 11422, 18656

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Aftermarket Cross References

• Sierra: 18-3061 / 18-3084 (verify)
• JMP: Equivalent applications (verify)
• Jabsco: Cross application (verify)

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Shipping

Shipping: Ships same or next day for fast Canada wide shipping.

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Parts Desk Insight

The 09959K is one of the most widely used Sherwood impellers in gas inboards. The key identifier is the 2-7/16″ diameter + 5/8″ keyed shaft—and note that some pumps run it paired with a 10615K, which is a common source of confusion