Lower Unit Gasket Kit – Fits Tohatsu/Nissan 8-9.8 HP (Replaces 3B2-87321-0, 5040536)
Lower Unit Gasket Kit – Fits Tohatsu/Nissan 8-9.8 HP (Replaces 3B2-87321-0, 5040536) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Lower Unit Gasket Kit – Fits Tohatsu/Nissan 8-9.8 HP (Replaces 3B2-...
Product Details
This Lower Unit Gasket Kit provides all necessary seals for servicing the lower unit on Tohatsu and Nissan 8 HP and 9.8 HP outboards. It is designed for 2-stroke M8B/M9.8B/NS8B/NS9.8B models from 2003 and 4-stroke MFS8A/MFS9.8A/NSF8A/NSF9.8A models from 2004–2014.
This kit offers a direct replacement for Tohatsu part numbers 3B2-87321-0, 3B2873210M, 3B2873211M, 3B2873213M, 3B2873214M, 3B2873215M, and is a cross-reference for Johnson/Evinrude 5040536.
- Engineered for direct-fit installation.
- Backed by a 1-year manufacturer warranty.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Notes |
|---|---|---|
| Tohatsu/Nissan | 3B2-87321-0 | Primary Part Number |
| Tohatsu/Nissan | 3B2873210M | Superseded |
| Tohatsu/Nissan | 3B2873211M | Superseded |
| Tohatsu/Nissan | 3B2873213M | Superseded |
| Tohatsu/Nissan | 3B2873214M | Superseded |
| Tohatsu/Nissan | 3B2873215M | Superseded |
| Johnson/Evinrude | 5040536 | Cross-reference only |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
For Tohatsu & Nissan Models: This kit fits the specific 2-stroke and 4-stroke models listed. Verify your model and serial number prefix.
For Johnson & Evinrude Models: This kit cross-references to OEM part 5040536, but specific model compatibility is not confirmed. Verify your original part number before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Tohatsu | M8B | 8 | 2-Stroke | 2003 | 3B2-87321-0 | |
| Tohatsu | M9.8B | 9.8 | 2-Stroke | 2003 | 3B2-87321-0 | |
| Nissan | NS8B | 8 | 2-Stroke | 2003 | 3B2-87321-0 | |
| Nissan | NS9.8B | 9.8 | 2-Stroke | 2003 | 3B2-87321-0 | |
| Tohatsu | MFS8A2 | 8 | 4-Stroke | 2004 | 3B2-87321-0 | |
| Tohatsu | MFS9.8A2 | 9.8 | 4-Stroke | 2004 | 3B2-87321-0 | |
| Nissan | NSF8A2 | 8 | 4-Stroke | 2004 | 3B2-87321-0 | |
| Nissan | NSF9.8A2 | 9.8 | 4-Stroke | 2004 | 3B2-87321-0 | |
| Tohatsu | MFS8A3 | 8 | 4-Stroke | 2006, 2009–2014 | 3B2-87321-0 | |
| Tohatsu | MFS9.8A3 | 9.8 | 4-Stroke | 2006, 2009–2014 | 3B2-87321-0 | |
| Nissan | NSF8A3 | 8 | 4-Stroke | 2006, 2009–2014 | 3B2-87321-0 | |
| Nissan | NSF9.8A3 | 9.8 | 4-Stroke | 2006, 2009–2014 | 3B2-87321-0 | |
| Johnson/Evinrude | 5040536 | Cross-reference only |
Technical Specs
- Product Type
- Lower Unit Gasket Kit
- Installation
- Direct replacement
- Warranty
- 1 Year (YiheoZux brand)
What’s in the Box
- 3 x GASKET (332-60006-0)
- 1 x O-RING (345-65015-0)
- 1 x OIL SEAL (369-60111-0)
- 1 x GUIDE PLATE GASKET (3B2-65029-0)
- 1 x OIL SEAL (309-60111-0)
- 1 x PUMP CASE GASKET (LOWER) (3B2-65020-1)
- 1 x O-RING (369-66021-1)
- 1 x O-RING (332-66032-0)
- 1 x PUMP CASE GASKET (3B2-65018-0)
Installation Notes
- Disconnect the battery and ensure the engine is securely mounted in an upright position.
- Drain the lower unit gear lubricant completely.
- Carefully disassemble the lower unit, keeping all bolts and components organized. Note the location and orientation of each old gasket and seal.
- Thoroughly clean all mating surfaces to remove old gasket material, sealant, and corrosion. Surfaces must be perfectly clean and dry for a proper seal.
- Install the new gaskets and seals from the kit. Lightly lubricate seals with fresh gear lube before installation.
- Reassemble the lower unit, ensuring all components are aligned correctly. Tighten all bolts to the manufacturer's recommended torque specifications in the correct sequence.
- Refill the lower unit with new, manufacturer-specified gear lubricant to the correct level.
Troubleshooting & FAQ
How do I know if I need to replace my lower unit gaskets?
The most common sign of a failing lower unit seal is milky or discolored gear lube, which indicates water intrusion. Other signs include visible oil leaks around the propeller shaft or drain screws, or a recurring loss of gear lube.
Will this kit fit any Tohatsu or Nissan 8 or 9.8 HP engine?
No, it is model- and year-specific. Please use the compatibility table provided on this page to confirm that this kit fits your exact engine model and year. Do not rely on horsepower alone.
Is any special sealant required with these gaskets?
Generally, these gaskets are designed to be installed on clean, dry surfaces without additional sealant. However, always consult your engine's service manual, as some locations may specify a light application of a specific sealant.
What is the OEM equivalent vs. this aftermarket kit?
This is an aftermarket replacement part, not sourced from the original equipment manufacturer (OEM). It is engineered to meet or exceed OEM specifications for fit, form, and function, using comparable materials. All parts are made in an ISO 9002 certified facility and are batch-inspected for quality assurance.
How fast do you ship and what is the cost?
We offer fast worldwide shipping, with a typical transit time of 5–15 days for most regions. Standard shipping is free. If expedited options are available for your location, they will be presented at checkout.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter a problem, please contact our support team with your order number. Returns are accepted for unused items in their original condition within our standard return period. Please see our full policy page or contact us for instructions.
Safety & Important Info
- Verify images and specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
Payment & Security
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