Lower Unit Seal Kit – Fits Suzuki DT55/DT65 (Replaces 25700-94700)
Lower Unit Seal Kit – Fits Suzuki DT55/DT65 (Replaces 25700-94700) 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 Seal Kit – Fits Suzuki DT55/DT65 (Replaces 25700-94700)
Product Details
This Lower Unit Seal Kit is designed for Suzuki 2-Stroke outboard motors, specifically 55–65 HP models manufactured from 1988 to 1999. It provides all the necessary seals for a complete gearcase service.
This kit serves as a direct replacement for Suzuki OEM part number 25700-94700 and aftermarket part Sierra 18-8339.
- Contains all required seals to disassemble and reseal the gearcase.
- Engineered for use with standard marine gasoline engines.
- Professional installation is recommended for optimal performance and safety.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Suzuki | 25700-94700 |
| Sierra | 18-8339 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Suzuki owners, ensure your model and year fall within the ranges specified below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Suzuki | DT55 | 55 | 2-Stroke | 1988–1999 | 25700-94700 |
| Suzuki | DT65J-X | 65 | 2-Stroke | 1988–1999 | 25700-94700 |
Technical Specs
- Product Type
- Lower Unit/Gear Case Seal Kit
- Fuel Type
- Gasoline
- Dimensions
- 7.13″ L × 6.0″ W × 0.63″ H
- Weight
- 38 g (0.08 lb)
- Contents
- Contains all required seals to disassemble and reseal the gearcase
What’s in the Box
- A complete seal kit for lower unit gearcase service, containing all seals required for disassembly and reassembly.
Installation Notes
Professional installation is highly recommended to ensure a proper fit and leak-free performance. The process typically involves draining the gear oil, removing the lower unit, carefully disassembling the gearcase, replacing all seals and O-rings from the kit, and reassembling using the correct torque specifications and fresh lubricant. Always consult your engine's official service manual for detailed, model-specific instructions.
Troubleshooting & FAQ
How do I know if this seal kit fits my Suzuki outboard?
This kit is specifically designed for Suzuki DT55 and DT65 models (55–65 HP) manufactured between 1988 and 1999. To ensure compatibility, please verify your exact engine model and year against the information in the Engine & Model Compatibility table.
What are the signs of a failing lower unit seal?
Common signs that your gearcase seals may need replacement include milky or water-contaminated gear oil (which looks like coffee with cream), visible oil leaks around the propeller shaft or driveshaft, or an unusual burning smell coming from the lower unit after operation.
Can I replace just one leaking seal instead of the whole kit?
It is strongly recommended to replace all seals and O-rings in the kit at the same time. Seals wear at a similar rate, and replacing only one may soon lead to a leak from another old seal. A complete overhaul ensures a reliable, long-lasting repair.
How often should lower unit seals be replaced?
There is no fixed replacement interval. Seals should be inspected for damage, brittleness, or leaks during every routine lower unit service (e.g., annual gear oil change). It is good practice to replace them preventatively after several seasons of use, especially in saltwater environments.
What’s the difference between OEM and aftermarket parts?
This listing is for an aftermarket replacement part, not an original equipment manufacturer (OEM) component. It has been engineered to meet or exceed OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 certified facility and are batch-inspected to ensure quality and consistency.
How fast is shipping and what does it cost?
We ship worldwide, with typical transit times of 5–15 days for most regions. Standard shipping is free. If expedited shipping options are available for your location, they will be presented at checkout for an additional fee.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal use conditions. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original condition. See our official policy page or reach out for detailed instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears on the compatibility list—do not purchase.
- This is an aftermarket replacement part, not an OEM component.
- Professional installation is recommended for safety and optimal performance.
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 parts typically arriving in 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
Payment & Security
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