Drive Shaft Housing Gasket – Fits Mercury/Mariner 15–25 HP (Replaces 27-433374)

$9.40 $15.00

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Drive Shaft Housing Gasket – Fits Mercury/Mariner 15–25 HP (Replaces 27-433374) is backordered and will ship as soon as it is back in stock.

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Product Details

This aftermarket Drive Shaft Housing Gasket is designed for a wide range of Mercury and Mariner 15–25 HP 2-stroke outboard engines from the 1990s through the 2000s, including popular variants like the Sea Pro, Marathon, Super 15, and Jet 20 models.

It serves as a direct replacement for multiple OEM part numbers, including Mercury 27-433374, 27-43337, 27-43337A1, 433374, 433373, 433372, 433371, and 27-96286.

Installation Location: Mounts between the drive shaft housing and the engine block.
Material: Constructed from a durable paper/composite blend for a reliable seal.
Engine Fitment: Compatible with various 15, 20, and 25 HP 2-cylinder models.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Mercury	27-433374
Mercury	27-43337
Mercury	27-43337A1
Mercury	433374
Mercury	433373
Mercury	433372
Mercury	433371
Mercury	27-96286

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This gasket fits a variety of 2-stroke outboards manufactured by Mercury and Mariner.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.
Mercury	15 MARATHON XD	15	2-Stroke	9927000-0P016999	27-433374
Mercury	15 MARATHON XD	15	2-Stroke	0P017000-0P325499	27-433374
Mercury	15 SEA PRO (XD)	15	2-Stroke	9927000-0P016999	27-433374
Mercury	15 SEA PRO (XD)	15	2-Stroke	0P017000-0P325499	27-433374
Mercury	20 (2 CYL.)	20	2-Stroke	9807909-0P016999	27-433374
Mercury	20 (2 CYL.)	20	2-Stroke	0G044027-0G760299	27-433374
Mercury	20 (2 CYL.)	20	2-Stroke	0P017000-0P325499	27-433374
Mercury	20 (2 CYL.)	20	2-Stroke	0G760300-0T979999	27-433374
Mercury	20 (2 CYL.)	20	2-Stroke	0P325500 & Up	27-433374
Mercury	20 JET	20	2-Stroke	9807909-0P016999	27-433374
Mercury	20 JET	20	2-Stroke	0G044027-0G760299	27-433374
Mercury	20 JET	20	2-Stroke	0P017000-0P325499	27-433374
Mercury	20 JET	20	2-Stroke	0G760300-0T979999	27-433374
Mercury	20 JET	20	2-Stroke	0T980000-0T999999	27-433374
Mercury	20 JET	20	2-Stroke	1B000001 & Up	27-433374
Mercury	25 (2 CYL.)	25	2-Stroke	0P325500 & Up	27-433374
Mercury	25 (2 CYL.)	25	2-Stroke	0T980000-0T999999	27-433374
Mercury	25 (2 CYL.)	25	2-Stroke	1B000001 & Up	27-433374
Mercury	25, 25 MARATHON, SUPER 15 (2 CYL.)	25	2-Stroke	9807909-0P016999	27-433374
Mercury	25, 25 MARATHON, SUPER 15 (2 CYL.)	25	2-Stroke	0G044027-0G760299	27-433374
Mercury	25, 25 MARATHON, SUPER 15 (2 CYL.)	25	2-Stroke	0P017000-0P325499	27-433374
Mercury	25, 25 MARATHON, SUPER 15 (2 CYL.)	25	2-Stroke	0G760300-0T979999	27-433374
Mercury	25, 25 SEA PRO, SUPER 15 (2 CYL.)	25	2-Stroke	9807909-0P016999	27-433374
Mercury	25, 25 SEA PRO, SUPER 15 (2 CYL.)	25	2-Stroke	0G044027-0G760299	27-433374
Mercury	25, 25 SEA PRO, SUPER 15 (2 CYL.)	25	2-Stroke	0P017000-0P325499	27-433374
Mercury	25, 25 SEA PRO, SUPER 15 (2 CYL.)	25	2-Stroke	0G760300-0T979999	27-433374

Technical Specs

Product Type: Gasket
Installation: Drive Shaft Housing
Housing Material: Paper/Composite
Dimensions: 22.0 × 12.0 × 0.5 in (approx. 559 × 305 × 13 mm)
Weight: 0.04 lb (0.018 kg)
Other Technical Attributes: Built to OEM specifications

What’s in the Box

1 x GASKET Drive Shaft Housing (Replaces 27-433374)

Installation Notes

Disconnect the battery and ensure the engine is off and cool.
Place a drain pan under the lower unit and drain the gearcase lubricant.
Remove the bolts securing the lower unit (gearcase) to the midsection.
Carefully separate the lower unit to expose the drive shaft housing and the old gasket.
Remove the old gasket and thoroughly clean both mating surfaces, ensuring they are free of old material, oil, and corrosion.
Position the new gasket correctly on the drive shaft housing.
Reattach the lower unit, ensuring the driveshaft and water tube align correctly.
Tighten the bolts to the manufacturer's recommended torque specifications.
Refill the gearcase with the correct type and amount of lubricant.
Once assembled, check for any leaks before operating the engine on the water.

Troubleshooting & FAQ

How do I know if this gasket fits my engine?

This gasket is for specific Mercury/Mariner 15–25 HP 2-stroke models. The most reliable method is to cross-reference your engine's serial number with the ranges listed in the compatibility table above. The "Years" column uses serial number ranges provided by the manufacturer.

What are the signs of a failed drive shaft housing gasket?

Common symptoms include water in the gearcase lubricant (milky or cloudy oil), oil leaking externally from the lower unit, or overheating caused by water pressure loss if the leak is severe. A visual inspection during routine maintenance may also reveal a brittle, cracked, or deteriorated gasket.

Can I reuse my old gasket after disassembly?

No. Gaskets are designed for single use. They compress and deform to create a seal. Once removed, a gasket will not provide a reliable seal again and should always be replaced with a new one to prevent leaks.

How often should this gasket be replaced?

This gasket should be replaced any time the lower unit is removed for service, such as during a water pump impeller replacement. There is no fixed time-based interval, but replacement during other lower unit maintenance is a standard preventative practice.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost?

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns?

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs 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

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