Prop Shaft Oil Seal – Fits Mercury/MerCruiser, Force & OMC (Replaces Mercury 26-14077, 26-76868; Johnson/Evinrude 320862)

Product Details

This replacement Prop Shaft Oil Seal is intended for selected Mercury and MerCruiser sterndrive applications, Mercury V6 2-stroke outboards, OMC Cobra and Stringer drives, and selected Force outboards. Confirm the specific model, serial range, OEM reference and dimensions before ordering.

The seal is designed for applications using a 1.187-inch (30.15 mm) propeller-shaft diameter. Its listed seal outside diameter is 1.687 inches (42.85 mm), with a housing bore specification of 1.692 inches (43.00 mm).

Reference numbers associated with this replacement include Mercury 26-14077 and 26-76868; Johnson/Evinrude 320862, 508520, 775424 and 778172; Sierra 18-2002 and 18-2077; GLM 85130; Mallory 9-76119; and Force F697555.

• Press-fit installation in the gearcase housing.
• Nitrile rubber sealing element with a metal case.
• Many applications use two prop-shaft seals per shaft; verify the service manual for your gearcase before ordering.

Part Number Matrix

Use these references as cross-reference leads and verify the number against your original seal and service documentation.

Engine & Model Compatibility

Compatibility depends on the exact gearcase, model and serial-number range. The tables below summarize the associated applications; they are not a substitute for checking the engine identification plate and service manual.

Johnson/Evinrude and OMC Applications

This seal is associated with selected Johnson/Evinrude outboards and OMC drives using a 1.187-inch propeller-shaft outside diameter.

Force Applications

Associated with selected early-1990s Force outboard applications.

Technical Specs

Product Type

Prop Shaft Oil Seal

Installation

Press fit

Propeller-Shaft Diameter

1.187 inches (30.15 mm)

Seal Outside Diameter

1.687 inches (42.85 mm)

Housing Bore

1.692 inches (43.00 mm)

Width/Height

0.250 inches (6.35 mm)

Material

Nitrile rubber with metal case

Color

Black/metallic

Typical Temperature Range

-40°C to 120°C (-40°F to 248°F) for the listed nitrile material

Application Note

Many gearcases use two prop-shaft seals per shaft; confirm the required quantity for the specific application.

What’s in the Box

• 1 × Prop Shaft Oil Seal

This listing is for one individual seal, not a complete seal set. If your gearcase requires two seals, order the quantity specified by the service manual.

Installation Notes

1. Drain the gearcase lubricant completely and secure the lower unit safely before beginning work.
2. Remove the propeller, bearing carrier and propeller-shaft assembly according to the applicable service manual.
3. Inspect the old seals and note their orientation before removal. Some applications use two seals installed back-to-back.
4. Use a seal puller or suitable tool to remove the old seal without scratching the housing.
5. Clean the housing bore and propeller shaft, removing old sealant, corrosion and debris.
6. Apply a thin layer of suitable marine lubricant to the outer metal edge of the seal and the housing bore if permitted by the service manual.
7. Using a seal driver or correctly sized socket, press the seal evenly and squarely into the bore until it is fully seated.
8. If a second seal is required, install it in the orientation specified by the service manual.
9. Lubricate the sealing lip and shaft surface before reinstalling the shaft to avoid damaging the new seal.
10. Reassemble the components in reverse order, replacing gaskets or O-rings as required and tightening fasteners to the manufacturer’s specifications.
11. Refill the gearcase with the specified lubricant and perform a pressure or leak test before returning the boat to service.

Troubleshooting & FAQ

Safety & Important Information

• Verify the engine or sterndrive model, year or serial range, reference number and dimensions before purchase.
• Compare the replacement seal with the original part before installation.
• Use the applicable factory or professional service manual for disassembly, seal orientation, torque values and pressure testing.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended when lower-unit service tools or procedures are unfamiliar.

About Sea Sierra

• Marine Replacement Parts — Parts selected for common service and repair applications.
• Cross-Reference Support — Product references help customers compare replacement parts with their original components.
• Practical Product Information — Specifications and installation notes are provided to support correct part verification and service planning.