Sherwood — Water Pump Cam Alignment Pin — S21566
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The Sherwood 21566 Water Pump Cam Alignment Pin is a genuine-style internal pump hardware component used in compatible Sherwood G-Series marine raw water pumps. This pin helps secure and align the internal cam plate inside the pump housing so the flexible impeller can compress properly and move cooling water through the engine’s raw water system.
It is a small but important service part when rebuilding or repairing Sherwood pumps where the cam plate, impeller, cover plate, or pump housing has been removed.
Key Features
- Sherwood raw water pump cam alignment pin.
- Part number: 21566.
- Common typed format: S21566 pin.
- Component type: pump cam alignment / plate pin.
- Secures the internal offset cam plate inside the pump body.
- Helps maintain proper cam-to-impeller alignment.
- Supports correct impeller compression and raw water flow.
- Used during pump repair, cam replacement, or raw water pump rebuild service.
- Built for compatible Sherwood G-Series marine cooling pumps where specified.
Pump Compatibility
Common application context includes Sherwood G-Series raw water pumps where 21566 is shown in the pump parts diagram, including:
- Sherwood G1804
- Sherwood G1805
- Sherwood G1806
- Sherwood G1807
- Sherwood G1808
- Sherwood G1810
- Sherwood G1811
- Sherwood G1814
- Sherwood G1815
- Sherwood G1816
- Sherwood G2201
- Sherwood G2902
- Sherwood G2903
- Sherwood G2904
- Sherwood G3001
These pump families are commonly used on marine raw water cooling systems for engines and generator packages from manufacturers such as Caterpillar, Cummins, Kohler, and John Deere where the pump model and parts diagram confirm this pin.
Fitment Notice
Confirm fitment by Sherwood pump model, pump serial or casting details, cam plate part number, and pump parts diagram before ordering. Sherwood G-Series pumps may share similar housings but use different cams, impellers, cover plates, pins, seals, and rebuild components depending on pump configuration.
This listing is for the cam alignment pin only. It is not the cam plate, impeller, cover gasket, shaft, seal kit, bearing kit, or complete pump assembly.
When This Part Needs Replacement
Replace the cam alignment pin if it is missing, bent, corroded, worn, loose, damaged during disassembly, or no longer holds the cam plate securely in the pump housing. Replacement is also recommended during pump rebuilds if the original pin shows saltwater corrosion or poor seating.
A worn or missing cam pin can allow the cam plate to shift, which may reduce raw water flow, damage the impeller, accelerate vane wear, or cause pump noise and overheating issues.
Installation Notes
Disassemble the pump according to the Sherwood service procedure and inspect the pump housing, cam plate, pin bore, impeller cavity, wear plate, and cover surface. Install the cam alignment pin fully into the correct location so the cam plate seats squarely and cannot move under impeller load.
When rebuilding the pump, inspect related parts at the same time, including the impeller, cam, cover plate, cover gasket or O-ring, shaft seal, bearings, and mounting hardware. After reassembly, prime the pump properly, check for leaks, and confirm strong raw water discharge after startup.
Related Service Parts
- Sherwood 21566 — cam alignment / plate pin
- Sherwood G-Series cam plate — verify by exact pump model
- Sherwood G-Series impeller kit — verify by pump model and impeller dimensions
- Sherwood cover gasket or O-ring — verify by pump model
- Sherwood pump rebuild kit — verify by pump model and service requirement
- Sherwood shaft seal / bearing components — verify by pump model
Parts Desk Insight
This pin controls the cam plate’s position inside the pump. If the cam shifts, the impeller may not compress correctly, which can reduce cooling flow and damage the rubber vanes. During any G-Series pump rebuild, verify the cam, pin, impeller, and cover plate together rather than replacing only the visible worn part.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
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We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
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Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
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