MerCruiser Drive Install O-Ring Kit – Fits Bravo 1/2/3 Stern Drives (Replaces 16755Q1)

$99.99

Shipping calculated at checkout.

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 MerCruiser Drive Install O-Ring Kit provides the essential O-rings and gaskets needed for the installation of the bell housing on MerCruiser Bravo 1, Bravo 2, and Bravo 3 series stern drives. The kit ensures a proper seal to prevent water intrusion and lubricant leaks.

This kit serves as a direct replacement for Mercury MerCruiser part number 16755Q1.

Designed for bell housing installation on Bravo series drives.
Includes all required seals for a complete service.
Meets or exceeds OEM specifications for fit and function.

Part Number Matrix

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

Brand	Part Number
Mercury MerCruiser	16755Q1

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For MerCruiser applications, this kit is specifically designed for the Bravo drive series listed below.

Brand	Model	Rated HP	Stroke	OEM Part No.
MerCruiser	Bravo 1	All	4-Stroke	16755Q1
MerCruiser	Bravo 2	All	4-Stroke	16755Q1
MerCruiser	Bravo 3	All	4-Stroke	16755Q1

Technical Specs

Product Type: Drive Install O-Ring Kit
Installation: Bell Housing
Fitting Type: O-Rings and Gaskets
Dimensions: L: 0.25 in x W: 7.13 in x H: 6.0 in
Warranty: OEM Warranty

What’s in the Box

1 x Seal Bell Housing to Driveshaft Housing (16755)
2 x O-Ring .924 X .103 (25-29845)
1 x O-Ring 1.046 X .139 (25-35027)
1 x O-Ring 1.424 X .103, Special (25-457101)
1 x O-Ring .739 X .070 (CP) (25-62705)

Installation Notes

Disconnect the boat's battery and follow all safety precautions.
Drain the stern drive gear lube completely.
Carefully remove the stern drive unit from the bell housing assembly.
Remove the bell housing to access the old seals and O-rings.
Thoroughly clean all mating surfaces, ensuring they are free of old gasket material, corrosion, and debris.
Lightly lubricate the new O-rings with a suitable marine grease before installation.
Install the new O-rings and gaskets from the kit in their correct locations.
Reinstall the bell housing and stern drive, torquing all fasteners to the manufacturer's specifications.
Refill the drive with fresh gear lube and check for leaks before operating.

Troubleshooting & FAQ

How do I know if this kit fits my Bravo drive?

This kit is designed for all MerCruiser Bravo 1, 2, and 3 stern drive models. To guarantee fitment, always cross-reference the OEM part number 16755Q1 with the part you are replacing.

What are the signs of a failed bell housing seal?

Common symptoms include water in the gear lube (which gives it a milky or creamy appearance), visible lubricant leaking from the drive, or water getting into the universal joint bellows.

When should these seals be replaced?

It is best practice to replace these O-rings and gaskets every time the stern drive unit is removed for any type of service. This preventative maintenance helps ensure a watertight seal.

What is the most common installation mistake?

The most frequent error is failing to properly clean the sealing surfaces before installing the new seals. Any old gasket material, salt deposits, or corrosion can compromise the seal and lead to immediate leaks.

Can I reuse my old seals if they look okay?

No. O-rings and gaskets are single-use components that compress and conform to the surfaces they seal. Reusing them significantly increases the risk of leaks and subsequent damage to the drive components.

Is any special lubricant needed for installation?

Using a small amount of 2-4-C marine grease or gasket sealing compound on the O-rings can help hold them in place during assembly and ensure a better seal. Do not use heavy grease that could block passages.

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.

Payment & Security

Payment methods

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.