Grease Seal 19643 – Fits Mercury/Mercruiser Sterndrives (Replaces Mercury 19643, SKF 19643)

$5.50

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Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This Grease Seal 19643 is engineered from high-grade nitrile rubber (NBR), designed for demanding industrial and mechanical applications that require reliable lubricant retention. It is specifically manufactured to serve as a direct replacement for multiple Mercury/Mercruiser sterndrive applications, ensuring a precise fit and durable performance.

It provides a direct interchange for Mercury/Mercruiser 19643, SKF 19643, and SEI Marine 98-299-09A/602-98-299-09A.

Designed for high-movement industrial environments.
Constructed from durable nitrile rubber for longevity.
Package includes one grease seal for a complete replacement.

Part Number Matrix

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

Brand	Part Number	Notes
Mercury/Mercruiser	19643	Factory original equipment part
SKF	19643
SEI Marine	98-299-09A/602-98-299-09A

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury/Mercruiser engines, this part is listed as a factory original equipment part replacement. Verify your specific model's requirements.

For Toyota vehicles, this part serves as an aftermarket replacement for the specified OEM number in certain model years. Always cross-reference part numbers.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury	Marine/Mercruiser				19643	Factory original equipment part
Toyota				1983–1988	90311-50003	Aftermarket replacement part

Technical Specs

Product Type: Grease Seal
Material: Nitrile rubber (NBR)
Dimensions: 5.13 × 4.0 × 0.25 in
Weight: 0.06 kg (0.14 lb)
Operating Temperature: Up to 100°C (212°F)
Application: Industrial applications with movement and need for lubricant retention

What’s in the Box

1 × Grease Seal (19643)

Installation Notes

Thoroughly clean the shaft and housing bore, ensuring both surfaces are smooth and free from debris, rust, or burrs.
Lightly lubricate the outer diameter of the grease seal with a lubricant compatible with the housing material.
Apply the same grease that the seal will retain to the inner sealing lip to prevent dry running on startup.
Position the seal squarely at the mouth of the bore, ensuring the sealing lip faces the correct direction to retain the lubricant.
Use a proper seal installation tool or an arbor press to apply slow, even pressure to the seal's outer metal casing. Press it in until it is fully and evenly seated in the bore.
After installation, double-check that the seal is not tilted or damaged and sits flush as intended.

Troubleshooting & FAQ

How do I know if this grease seal will fit my sterndrive?

The best way to confirm fitment is to match your existing part number to the ones listed in our Part Number Matrix. This seal replaces Mercury/Mercruiser 19643, SKF 19643, and SEI Marine 98-299-09A. Always verify the dimensions against your old part if possible.

What are the signs of a failing grease seal?

Common signs of a bad seal include visible grease leakage around the shaft or housing, contamination of the lubricant (e.g., water ingress), or unusual grinding/whirring noises from bearings that have lost their lubrication.

What's the difference between this nitrile rubber (NBR) seal and other types?

Nitrile rubber (NBR) is a versatile and widely used material known for its excellent resistance to oils, fuels, and other petroleum-based lubricants. It provides a durable, cost-effective sealing solution for a wide range of common temperatures and applications.

Can I reuse a grease seal?

No. Grease seals are designed for single use only. The removal process almost always damages or distorts the delicate sealing lip or the outer casing, rendering it ineffective. Always install a new seal during any service or repair.

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

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.

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