Water Pump Impeller Kit – Fits Tohatsu/Nissan 40/50 HP 2-Stroke TLDI & 4-Stroke Outboards (Replaces 3T5-87322-3)
This water pump impeller service kit is designed for Tohatsu and Nissan 40–50 HP, 2-Stroke TLDI & 4-Stroke outboard motors from 2010–2014. It provides a reliable solution for maintaining your engine’s cooling system to prevent overheating and ensure optimal performance.
Engineered as a direct replacement for multiple OEM part numbers, this kit simplifies maintenance and ensures a precise fit. It directly replaces Tohatsu/Nissan parts 3T5-87322-3, 3T5-87322-2, 3T5-87322-1, and 3T5-87322-0 series, as well as Mercury/Mariner part 46-8M0046094.
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Complete Service Kit: Includes a neoprene impeller, housing liner, key, gaskets, and bolts for a full-system refresh.
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Durable Materials: Features a tough neoprene rubber impeller for wear resistance and a high-strength Nylon PA66 plastic housing.
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Direct Installation: Built to match OEM specifications for a straightforward, direct replacement installation.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Tohatsu/Nissan |
3T5-87322-3 / 3T5-87322-3M |
| Tohatsu/Nissan |
3T5-87322-2 / 3T5-87322-2M (Superseded) |
| Tohatsu/Nissan |
3T5-87322-1 / 3T5-87322-1M (Superseded) |
| Tohatsu/Nissan |
3T5-87322-0 / 3T5-87322-0M (Superseded) |
| Mercury/Mariner |
46-8M0046094 |
Compatible Engine Models
Confirm your engine model/year in the table below.
Tohatsu Outboards
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Tohatsu |
MD40B2 |
40 |
2-Stroke TLDI |
2010–2014 |
3T5-87322-3 |
- |
| Tohatsu |
MD50B2 |
50 |
2-Stroke TLDI |
2010–2014 |
3T5-87322-3 |
- |
| Tohatsu |
MFS40A |
40 |
4-Stroke |
2014 |
3T5-87322-3 |
- |
| Tohatsu |
MFS50A |
50 |
4-Stroke |
2014 |
3T5-87322-3 |
- |
| Tohatsu |
MD40B(AQ) |
40 |
2-Stroke TLDI |
2006 |
3T5-87322-3 |
- |
| Tohatsu |
MD50B(AQ) |
50 |
2-Stroke TLDI |
2006 |
3T5-87322-3 |
- |
Nissan Outboards
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Nissan |
NSD40B2 |
40 |
2-Stroke TLDI |
2010–2014 |
3T5-87322-3 |
- |
| Nissan |
NSD50B2 |
50 |
2-Stroke TLDI |
2010–2014 |
3T5-87322-3 |
- |
| Nissan |
NSF40A |
40 |
4-Stroke |
2014 |
3T5-87322-3 |
- |
| Nissan |
NSF50A |
50 |
4-Stroke |
2014 |
3T5-87322-3 |
- |
| Nissan |
NSD40B(AQ) |
40 |
2-Stroke TLDI |
2006 |
3T5-87322-3 |
- |
| Nissan |
NSD50B(AQ) |
50 |
2-Stroke TLDI |
2006 |
3T5-87322-3 |
- |
Technical Specifications
| Specification |
Value |
| Product Type |
Water Pump Impeller Service Kit |
| Installation |
Direct replacement |
| Housing Material |
Nylon PA66 Plastic |
| Housing Color |
Black |
| Impeller Material |
Neoprene Rubber |
| Warranty |
1 Year |
Package Contents
- 1 x Water Pump Impeller (3C8-65021-2)
- 1 x Impeller Key (332-65022-0)
- 1 x Pump Case Liner/Insert (3T5-65011-0)
- 1 x Water Pump Guide Plate (3C8-65025-0)
- 1 x Guide Plate Gasket (3C8-65029-0)
- 1 x Pump Case Gasket (3C8-65018-0/3T5-65018-2)
- 4 x Screw/Bolt (910113-5855/9101E3-5855)
Installation Guide
- Disconnect the battery and shift the outboard into the neutral position.
- Remove the lower unit (gearcase) by unbolting it from the engine's midsection and disconnecting the shift linkage.
- Place the lower unit on a workbench and remove the bolts securing the water pump housing.
- Slide the housing up the driveshaft to expose the old impeller. Pay attention to the original orientation of the impeller vanes.
- Remove the old impeller, woodruff key, gaskets, wear plate, and housing insert. Thoroughly clean all surfaces of any old gasket material or debris.
- Install the new pump case liner and guide plate gasket.
- Place the new impeller key in the driveshaft slot.
- Apply a light coat of marine grease to the inside of the new impeller and slide it onto the driveshaft. Rotate the driveshaft clockwise to help seat the vanes correctly inside the housing.
- Lubricate the inside of the pump housing with grease and install it over the impeller, ensuring it is properly seated.
- Fasten the housing with the new bolts, tightening them to the manufacturer's specified torque.
- Re-install the lower unit onto the outboard, re-connecting the shift linkage and all bolts.
- Once fully assembled, reconnect the battery and test the engine in the water, confirming a strong, steady stream of water from the tell-tale outlet.
Troubleshooting & FAQ
How do I confirm this kit will fit my specific engine?
Start by checking the "Compatible Engine Models" table on this page. Compare your engine's brand, model, horsepower, and year against the listed models. It is also critical to cross-reference your existing part number with those in the "Part Number Cross-Reference" table to ensure an exact match.
What are the common signs of a failing water pump impeller?
The most common symptoms include the engine running hotter than usual, a weak or non-existent water stream from the tell-tale (water discharge outlet), or an engine overheat alarm. If you notice any of these signs, inspect your water pump system immediately.
How often should I replace the water pump impeller?
For preventative maintenance, it is recommended to replace your water pump impeller and service the kit every 100-200 operating hours or at least once a year, whichever comes first. This is especially important if you frequently operate in sandy, silty, or saltwater environments.
OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.