Sherwood 762-09959K Impeller Kit – Neoprene w/ Gasket & O-Ring

The Sherwood 09959K is a complete flexible impeller service kit for a broad range of Sherwood engine-cooling raw-water pumps. Its 12-blade neoprene impeller uses a 5/8-inch keyed hub with a 3/16-inch keyway and is designed to restore reliable freshwater or seawater circulation through compatible marine cooling systems. The kit includes the 09959 impeller, associated gaskets, O-ring and technical service instructions.

Key Features

• Sherwood manufacturer part number: 09959K
• Distributor SKU: 762-09959K
• Neoprene flexible impeller
• 12 flexible blades
• Outside diameter: 2-7/16 inches / approximately 62 mm
• Width: 1-1/4 inches / approximately 32 mm
• Shaft diameter: 5/8 inch / approximately 15.9 mm
• Drive connection: keyed hub
• Keyway: 3/16 inch
• Maximum published neoprene operating temperature: 130°F
• Kit includes impeller, gasket or gaskets, O-ring and technical guide
• UPC: 734943102865

Pump Compatibility

Sherwood’s technical application guide associates 09959K with numerous genuine Sherwood pumps, including:

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

Certain dual-impeller pumps require two 09959K kits, while some pump assemblies use one 09959K together with one 10615K.

Engine Compatibility

Pump-based application references associate this impeller with selected marine engines and generators from:

• Chris-Craft
• Chrysler Marine
• Crusader
• PCM and Pleasurecraft
• Perkins
• Onan
• Universal
• Westerbeke
• OMC and Volvo Penta installations equipped with compatible Sherwood pumps

It is also commonly used in PCM Ford belt-driven raw-water pumps and Commander Ford installations fitted with the Sherwood J70 pump. Exact engine compatibility depends on the installed pump model rather than engine brand alone.

Fitment Notice

Confirm that the installed pump requires:

• Sherwood 09959K
• 2-7/16-inch impeller diameter
• 1-1/4-inch impeller width
• Twelve flexible blades
• 5/8-inch shaft
• 3/16-inch keyway
• Keyed hub rather than a splined connection

Several Sherwood impellers have similar diameters but differ in width, shaft size or drive configuration. Always match the pump model and original impeller dimensions before ordering.

When This Part Needs Replacement

Replace the impeller when:

• Cooling-water flow becomes weak or intermittent
• The engine begins operating hotter than normal
• Cooling or exhaust-temperature alarms activate
• The vanes are cracked, torn, stiff or permanently bent
• Pieces are missing from the impeller
• The keyed hub shows wear or begins slipping
• The pump has operated without an adequate water supply
• The pump has ingested sand, silt or debris
• The scheduled cooling-system service interval has been reached

A damaged impeller may continue rotating while producing significantly reduced cooling-water flow.

Installation Notes

Before installation:

• Shut down the engine and isolate the starting system
• Close the raw-water seacock
• Remove the pump cover and existing sealing components
• Note the direction of the old impeller vanes
• Recover all broken rubber fragments from the pump and downstream cooling circuit
• Inspect the pump cover, cam, housing, shaft and drive key
• Lubricate the new impeller with glycerine, soapy water or an approved rubber-safe lubricant
• Align and seat the 3/16-inch key correctly
• Install the supplied gasket and O-ring
• Reassemble the pump according to its technical guide
• Reopen the seacock and confirm strong cooling-water flow before operating under load

Never operate a flexible impeller pump dry.

Alternate / Cross-Reference Part Numbers

• Sherwood: 09959K
• Distributor SKU: 762-09959K
• Sherwood impeller-only number: 09959
• Alternate format: 09959K-SHW
• Earlier Sherwood references: 10685, 10687, 11422, 18656 and 18838
• Perkins: 24880178
• Perkins: NA900012
• Onan: 132-0117
• Onan: 132-0317
• Universal/Westerbeke: 11418
• Universal/Westerbeke: 11907
• Universal/Westerbeke: 33104
• Sierra: 18-3061
• UPC: 734943102865

Parts Desk Insight

The 09959K and 10615K both use a 5/8-inch keyed shaft, but they are different sizes: 09959K is 1-1/4 inches wide, while 10615K is 1-5/8 inches wide. Confirm the pump model and impeller width carefully, particularly on Sherwood pumps that use both impeller sizes in the same assembly.

Compatible & Related Products

• Sherwood 09959K Impeller Kit – Alternate listing / cross-reference
• Sherwood Water Pump Cam Alignment Pin S21566 – Required for correct cam orientation on reassembly
• Sherwood Impeller Puller 25106 – Recommended for safe impeller removal
• Sherwood Impeller Puller 17000K Series – Alternative removal tool

Parts Desk Insight – Best Use

The 762-09959K is a complete service kit — the "K" suffix confirms it includes all sealing components (gasket + O-ring) alongside the impeller blade. Note that an alternate listing exists in the catalog (09959K without the 762- prefix); verify with your supplier data which part number your customer's pump manufacturer references to avoid duplicate-order confusion. Before installation, inspect the pump housing bore for scoring; a worn bore will shorten impeller life regardless of kit quality. Use an impeller puller for removal to prevent blade tearing and fragment ingestion into the cooling circuit. Confirm cam orientation with alignment pin S21566 before closing the pump cover. Neoprene is the correct material for raw water applications at normal operating temperatures.