Lower Unit Seal Kit – Fits Mercury/Mariner 30-60 HP Outboards (Replaces 26-814669A2, 18-2635)
Lower Unit Seal Kit – Fits Mercury/Mariner 30-60 HP Outboards (Replaces 26-814669A2, 18-2635) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Lower Unit Seal Kit – Fits Mercury/Mariner 30-60 HP Outboards (Repl...
Product Details
This aftermarket Lower Unit Seal Kit is designed to service the small gearcase on a range of outboard motors. It fits Mercury/Mariner 30-60 HP 3-cylinder and 4-stroke 4-cylinder models from 1991–2012+, as well as Force 70-75 HP outboards from 1991–1998.
It serves as a direct replacement for Mercury 26-814669A2, Sierra 18-2635, GLM 87809, and WATERLONG 26-814669A2.
- Engineered to meet OEM specifications for fit and performance.
- Kit contains the necessary seals and O-rings for a lower unit service.
- Professional installation is recommended to ensure a proper seal and prevent leaks.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 26-814669A2 |
| Sierra | 18-2635 |
| GLM | 87809 |
| WATERLONG | 26-814669A2 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is applicable to various 3-cylinder and 4-stroke 4-cylinder Mercury and Mariner outboards, primarily in the 30-60 HP range.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 30 EFI | 30 | 3-Cyl (4-Stroke) | 2006–2012+ | 26-814669A2 | |
| Mercury | 40 | 40 | 4-Cyl (4-Stroke) | 2001–2006 | 26-814669A2 | |
| Mercury | 40 EFI | 40 | 3-Cyl (4-Stroke) | 2006–2012+ | 26-814669A2 | |
| Mercury | 40 EFI | 40 | 4-Cyl (4-Stroke) | 2001–2012+ | 26-814669A2 | |
| Mercury | 40 Carb | 40 | 3-Cyl (4-Stroke) | 2006–2012+ | 26-814669A2 | |
| Mercury | 40 Jet | 40 | 4-Stroke | 1999–2012+ | 26-814669A2 | |
| Mercury | 45 Jet | 45 | 3-Cyl | 1991–2004 | 26-814669A2 | |
| Mercury | 50 | 50 | 3-Cyl | 1991–2006 | 26-814669A2 | |
| Mercury | 50 | 50 | 4-Cyl (4-Stroke) | 2001–2002 | 26-814669A2 | |
| Mercury | 50 EFI | 50 | 4-Cyl (4-Stroke) | 2002–2012+ | 26-814669A2 | |
| Mercury | 55 | 55 | 3-Cyl | 1991–2006 | 26-814669A2 | |
| Mercury | 60 | 60 | 3-Cyl | 1991–2006 | 26-814669A2 | |
| Mercury | 60 Bigfoot | 60 | 3-Cyl | 1998–2004 | 26-814669A2 | |
| Mercury | 60 | 60 | 4-Cyl (4-Stroke) | 2001–2002 | 26-814669A2 | |
| Mercury | 60 EFI | 60 | 4-Cyl (4-Stroke) | 2002–2012+ | 26-814669A2 | |
| Mercury | Formula 60 | 60 | 4-Stroke | 2012+ | 26-814669A2 |
Fits select Force 3-cylinder outboards from the 1990s.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Force | 70 HP | 70 | 3-Cyl | 1991–1995 | 26-814669A2 | |
| Force | 75 HP | 75 | 3-Cyl | 1996–1998 | 26-814669A2 |
Technical Specs
- Product Type
- Lower Unit Seal Kit
- Application
- Small gearcase
- Gear Ratio
- 2:1
- Package Dimensions
- 11.25 × 6.0 × 0.75 in
- Package Weight
- 0.25 kg (0.55 lb)
- Installation
- Professional installation recommended
- Warranty
- Manufacturer dependent
What’s in the Box
Kit contents may vary slightly between aftermarket manufacturers but typically include:
- 1 x Lower Oil Seal (Replaces Mercury 814669)
- 1 x Upper Oil Seal (Replaces Mercury 814670)
- 1 x O-Ring (Replaces Mercury 30224)
- Various other seals and gaskets required for installation.
Installation Notes
While professional installation is recommended, the general steps are as follows:
- Disconnect the battery and shift the outboard into neutral.
- Place a drain pan under the lower unit and remove the upper (vent) and lower (drain) screws to drain the gear lube.
- Remove the propeller nut and propeller.
- Remove the bolts securing the lower unit to the midsection. Carefully lower the gearcase from the housing.
- Using appropriate seal pullers, remove the old driveshaft and propeller shaft seals from the carrier and housing.
- Thoroughly clean all sealing surfaces, removing any old sealant or corrosion.
- Carefully install the new seals and O-rings using seal drivers to ensure they are seated evenly and without damage.
- Reassemble the lower unit in the reverse order of removal.
- Refill the gearcase with fresh, marine-grade lower unit lubricant until it flows from the upper vent hole. Reinstall and tighten both screws.
- After a short on-water test, re-check the gear lube for any signs of water intrusion (milky appearance).
Troubleshooting & FAQ
How do I know if my lower unit seals are failing?
Common signs include milky or discolored gear lube from water intrusion, visible oil leaks around the propeller shaft or driveshaft housing, or a metallic sheen in the oil, which indicates potential bearing wear caused by water contamination.
Will this kit fit a "Bigfoot" or high-thrust model?
This kit is specifically for small gearcase models. While the Mercury 60 Bigfoot (1998–2004) is listed as compatible, it is critical to verify your engine’s specific OEM part number against our cross-reference list before ordering. Bigfoot models often use different gearcase components.
What is the recommended replacement interval for lower unit seals?
As a best practice, lower unit seals should be inspected annually and replaced whenever servicing the water pump impeller, or at least every 2-3 seasons. More frequent replacement may be necessary for boats operated in saltwater or high-hour applications.
Are special tools required for this installation?
Yes, proper installation requires specialized tools such as seal pullers, seal drivers or a bearing press, and snap-ring pliers. Using incorrect tools can easily damage the new seals or the gearcase housing, leading to premature failure.
My engine year is 2014, but the chart says 2012+. Will this fit?
The "2012+" designation suggests that the part fits models from 2012 and newer within that specific engine series. However, manufacturers can make mid-year changes. Always confirm compatibility by matching your engine's required OEM part number to the numbers listed in our Part Number Matrix.
Does this kit include every seal in the lower unit?
This kit includes the primary oil seals for the driveshaft and propeller shaft, along with essential O-rings for reassembly. It is designed to address the most common leak points. For a complete overhaul, additional gaskets or seals might be required depending on your specific model.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and batch-inspected for quality and consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free for most orders, and expedited options will appear at checkout if they are available for your location.
Warranty & returns
This product is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our policy page or reach out 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 component, not an Original Equipment Manufacturer (OEM) part.
- Professional installation is recommended for safety and performance. Incorrect installation can lead to gearcase failure.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with an average transit time of 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
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