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 engineered for a wide range of marine engines, including Mercury outboards (105-250 HP, 2-Stroke), MerCruiser Alpha One/Gen 2 sterndrives, and OMC Cobra/Stringer drives. It is specifically designed for applications requiring a 1.187" shaft diameter and a 1.687" bore size, ensuring a precise fit for various Johnson/Evinrude models with a 1.187" OD propshaft.

It serves as a direct interchange for Mercury parts 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.

• Installs via press fit into the gearcase housing.
• Constructed from durable nitrile rubber with a steel case for longevity.
• Note that in most applications, two seals are required per propshaft for a complete replacement.

Part Number Matrix

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

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury and MerCruiser models, this seal fits various sterndrives and V6 outboards. Check your serial number range to ensure correct fitment.

This seal fits numerous Johnson/Evinrude outboards and OMC sterndrives that use a propshaft with a 1.187" outside diameter.

Fits select Force outboard models from the early 1990s.

Technical Specs

Product Type

Prop Shaft Oil Seal

Installation

Press fit

Shaft Size

1.187" (30.15 mm)

Seal Outside Diameter

1.687" (42.85 mm)

Housing Bore

1.692" (43.00 mm)

Width/Height

0.250" (6.35 mm)

Material

Nitrile rubber with metal case

Color

Black/metallic

Operating Temperature

-40°C to 120°C (-40°F to 248°F) [typical for nitrile seals]

Other Technical Attributes

In most applications, 2 seals required per propshaft

What’s in the Box

• 1 x Prop Shaft Oil Seal

Installation Notes

1. Start by draining the gearcase oil completely. Safely secure the lower unit to work on it.
2. Remove the propeller, bearing carrier, and the propshaft assembly according to your service manual.
3. Carefully inspect the old seals for wear patterns and note their orientation (lip direction) before removal. Most applications use two seals installed back-to-back.
4. Use a seal puller or a flat-head screwdriver to carefully pry out the old seals from the housing bore. Avoid scratching or damaging the housing surface.
5. Thoroughly clean the seal housing bore and propshaft, removing any old sealant, corrosion, or debris.
6. Apply a thin layer of marine grease or 2-4-C lubricant to the outer metal edge of the new seal and the inside of the housing bore.
7. Using a seal driver or a socket with an outer diameter matching the seal's, gently and evenly press the first new seal into the bore until it is fully seated. Ensure it is straight.
8. Press the second seal into place, oriented according to your manual's instructions (typically back-to-back with the first).
9. Lubricate the inner lip of the seals and the propshaft surface before carefully reinserting the shaft to prevent damage.
10. Reassemble all components in reverse order, using new gaskets or O-rings as required. Torque all fasteners to the manufacturer’s specifications.
11. Refill the gearcase with the correct type and amount of new lubricant, and check for leaks by performing a pressure test before returning to the water.

Troubleshooting & FAQ

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.