Drain Screw Gasket – Fits Mercury/MerCruiser & Johnson/Evinrude Lower Units (Replaces 12-19183, 307552)
This drain screw gasket is designed for a wide range of outboard and stern drive lower units. It fits all Mercury/MerCruiser outboards and stern drives with 3/8-16 drain/fill screw holes (excluding Japanese-origin models), as well as all Johnson/Evinrude and Chrysler/Force/US Marine outboard lower units that use the same 3/8-16 thread size.
This gasket is a direct aftermarket replacement for multiple OEM part numbers, including Mercury 12-19183 / 12-19183Q02, Johnson/Evinrude 307552, Sierra 18-2945, GLM 31170, and Mallory 9-60101, ensuring broad compatibility and a secure fit.
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Material: Constructed from rubber-coated stainless steel to form a durable, tear-resistant seal without over-compression.
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Compatibility: For use with 3/8-16 drain/fill screw holes on specified models.
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Installation: Recommended for replacement with every gearcase oil change to prevent leaks.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury |
12-19183, 12-19183Q02, 12-19183K02, 12-191833, 191832, 19183, 19183B, 20260B, 20260 |
| Johnson / Evinrude |
307552, 300434 |
| Sierra |
18-2244, 18-2945, 18-29451-9 |
| GLM |
31170 |
| Mallory |
9-60101, 9-60102 |
| SEI Marine |
98-102-09 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson Serial Number Guide.
Mercury/MerCruiser
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Mercury |
Outboard Motors |
All |
2-Stroke & 4-Stroke |
All |
12-19183 |
Except Japanese origin models |
| Mercury |
Outboard Lower Units |
All |
2-Stroke & 4-Stroke |
All |
12-19183 |
For 3/8-16 drain/fill screw holes |
| MerCruiser |
All Stern Drives |
All |
N/A |
All |
12-19183 |
For 3/8-16 drain/fill screw holes |
| MerCruiser |
4.3L, 5.0L, 5.7L, 6.2L |
All |
N/A |
All |
12-19183 |
Confirmed fit |
| MerCruiser |
350, 377, 383 MPI |
All |
N/A |
All |
12-19183 |
Confirmed fit |
Johnson/Evinrude
| Brand |
Model |
Rated HP |
Stroke |
OEM Part No. |
Notes |
| Johnson/Evinrude |
Outboard Lower Units |
All |
2-Stroke & 4-Stroke |
307552 |
For 3/8-16 drain/fill screw holes |
| Johnson/Evinrude |
Multiple Models |
18-75 HP |
2-Stroke & 4-Stroke |
307552 |
Used with compatible drain screws |
Chrysler/Force/US Marine
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Chrysler/Force/US Marine |
Outboard Lower Units |
All |
2-Stroke & 4-Stroke |
All |
F50556, F8077, F8186 |
For 3/8-16 drain/fill screw holes |
Technical Specifications
| Specification |
Value |
| Product Type |
Drain/Fill Screw Gasket |
| Installation |
Use with 3/8-16 drain/fill screw holes |
| Housing Material |
Rubber-coated stainless steel |
| Housing Color |
Yellow (newer design) or Blue (older design) |
| Fitting Type |
Washer/Gasket |
| Thread Size |
3/8-16 |
| Other Technical Attributes |
Designed to form tear-resistant seal without requiring compression |
Package Contents
- 1 x Drain Screw Gasket (Replaces OEM 12-19183Q02)
Note: Please be aware that different vendors sell these gaskets in various pack quantities (e.g., 1, 2, 4, or 20 per package). This listing is for a single gasket.
Installation Guide
Always replace gaskets when changing gearcase oil to ensure a proper seal. Professional installation is recommended.
- Position a suitable drain pan underneath the lower unit’s drain screw.
- Using a large flathead screwdriver, remove both the lower drain screw and the upper vent screw.
- Allow the gearcase oil to drain completely. Check the old oil for a milky color (water intrusion) or metal shavings (gear wear).
- Discard the old gaskets from both screws. Thoroughly clean the sealing surfaces on the gearcase, removing any old gasket residue.
- Place the new gasket onto the drain screw.
- Insert the gear lube pump nozzle into the bottom drain hole and pump in fresh lubricant until it flows out of the upper vent hole.
- Install the upper vent screw with its new gasket and tighten it securely.
- Quickly remove the filler nozzle and reinstall the lower drain screw with its new gasket.
- Tighten the drain screw firmly until snug. Do not overtighten, as this can damage the gasket or threads.
- Wipe the area clean and inspect for any leaks after a short period.
Troubleshooting & FAQ
Q: How can I be sure this gasket fits my engine?
A: This gasket is designed for all Mercury, MerCruiser, Johnson/Evinrude, and Chrysler/Force lower units that use a 3/8-16 drain/fill screw. It is a direct replacement for part numbers like Mercury 12-19183 and Johnson/Evinrude 307552. Please note, it does not fit Mercury models of Japanese origin.
Q: How often should I replace my drain screw gaskets?
A: For best results and to prevent leaks, you should install a new gasket every time you change your gearcase oil. Reusing old gaskets can lead to a poor seal and potential water damage to your lower unit.
Q: My old gasket was blue, but this one is yellow. Is it the right part?
A: Yes. The color indicates the design version, with blue being an older style and yellow being the newer one. Both are made from rubber-coated stainless steel and are functionally identical, providing the same tear-resistant seal.
Q: What should I do if my drain plug still leaks after installing the new gasket?
A: First, ensure the sealing surface on the gearcase is completely clean and free of old gasket debris. Second, verify the screw is tightened to be snug but not overtightened. Excessive torque can damage the gasket. If leaks persist, inspect the threads on both the screw and the gearcase for damage.
Q: OEM vs. Aftermarket?
A: 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.
Q: How fast do you ship and how much does it cost?
A: 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.
Q: What is your warranty and return policy?
A: 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.