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U-Joint Oil Seal – Fits MerCruiser Bravo (Replaces 26-807006, 26-18816)

Regular price $15.00
Shipping calculated at checkout.

U-Joint Oil Seal – Fits MerCruiser Bravo (Replaces 26-807006, 26-18816) is backordered and will ship as soon as it is back in stock.


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

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 aftermarket U-Joint Oil Seal is designed for MerCruiser Bravo series (I, II, III, X, XR, XZ) and Blackhawk stern drives manufactured from 1988 and later, fitting serial numbers 0B664190 and up. It provides a secure seal within the drive shaft housing to prevent gear lube leakage and water intrusion.

It serves as a direct replacement for MerCruiser OEM part numbers 26-807006 and 26-18816, as well as GLM part 86730.

  • Installs in the upper drive shaft housing.
  • Constructed from a durable rubber and metal housing.
  • Package includes one oil seal.

Part Number Matrix

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

Brand Part Number
MerCruiser 26-807006
MerCruiser 26-18816
GLM 86730

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This seal fits a wide range of MerCruiser Bravo and Blackhawk stern drives. Please verify your drive model and serial number to ensure correct fitment before purchasing.

Brand Model Years OEM Part No. Notes
MerCruiser Bravo I 1988 and up 26-807006, 26-18816 Serial Range: 0B664190 and up
MerCruiser Bravo II 1988 and up 26-807006, 26-18816 Serial Range: 0B664190 and up
MerCruiser Bravo III 1988 and up 26-807006, 26-18816 Serial Range: 0B664190 and up
MerCruiser Blackhawk 1994–1995 26-807006, 26-18816 Serial Range: 0F186717 and up

Technical Specs

Product Type
U-Joint Oil Seal
Installation
Drive Shaft Housing
Housing Material
Rubber/Metal
Dimensions
2.25" OD × 1.6875" ID × 0.31" Thickness (57.15 mm × 42.86 mm × 7.87 mm)
Weight
0.07 lbs (0.032 kg)
Other Technical Attributes
For Universal Joint and Drive Shaft Housing

What’s in the Box

  • 1 x Oil Seal (Replaces 26-807006, 26-18816)

Installation Notes

  1. Ensure the engine is off and the stern drive is tilted to a safe, accessible working position.
  2. Remove the drive components nécessaires to access the U-joint and drive shaft housing area.
  3. Carefully pry out the old oil seal using a seal puller, taking care not to scratch the housing surface.
  4. Thoroughly clean the seal bore in the housing, removing any old sealant, corrosion, or debris.
  5. Apply a thin layer of 2-4-C marine grease to the inner and outer lip of the new seal.
  6. Position the new seal squarely over the bore.
  7. Use a seal driver or a socket of matching diameter to gently tap the seal into place until it is fully seated.
  8. Reassemble all stern drive components according to the manufacturer's specifications and torque values.

Troubleshooting & FAQ

How do I know if this seal will fit my MerCruiser drive?

This seal fits MerCruiser Bravo I, II, III, X, XR, and XZ drives from 1988+, and Blackhawk drives (1994–1995). The key is to match your drive's serial number. It must be 0B664190 or newer for Bravo drives and 0F186717 or newer for Blackhawk drives.

What are the symptoms of a failed U-joint oil seal?

The most common sign is gear lube leaking from the upper drive housing, often visible on the outside of the drive or in the bilge. Another critical symptom is milky or creamy gear lube, which indicates water has entered the drive through the failed seal.

When should I replace this seal?

It is highly recommended to replace this seal preventatively whenever you are servicing the U-joints, gimbal bearing, or bellows. There is no fixed service interval, but replacing it during other drive maintenance can prevent costly water intrusion and bearing failure.

Can I install this myself?

While DIY installation is possible for experienced mechanics, it requires specific tools like a seal puller and driver. Due to the critical nature of preventing water intrusion into the drive, professional installation is recommended to ensure a proper, leak-free fit.

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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