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Gearcase Gasket and Seal Kit – Fits OMC V6/V8/800 Series (Replaces 982946)

Regular price $32.50

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If the return is due to our error or a defective item, we’ll make it right.


Please contact us before returning any item.

Delivery and Shipping

Orders are typically processed within 1–2 business days.


U.S. orders usually arrive within 6–15 days, depending on stock location and destination.


International delivery times may vary due to customs processing.


Tracking information will be provided once your order ships.

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 Gearcase Gasket and Seal Kit is designed for OMC Stern Drive models, including V6, V8, 800 Series, 3.8L, 5.0L, and 5.7L engines manufactured between 1980 and 1985. It provides the essential components for servicing the lower gearcase. Please note, this kit is not compatible with OMC Cobra Stern Drive models.

It serves as a direct replacement for several OEM and aftermarket part numbers, including OMC 982946/0982946, Sierra Marine 18-2665, SEI Marine 95-105-11K, OBR Red Rhino OS-124, Mallory Marine 9-74400, and GLM 87630.

  • Application: For lower gearcase service.
  • Installation: Professional installation is recommended.
  • Compatibility: Specifically for non-Cobra OMC Stringer drives (1980–1985).

Part Number Matrix

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

Brand Part Number
OMC 982946 / 0982946
Sierra Marine 18-2665
SEI Marine 95-105-11K
OBR Red Rhino OS-124
Mallory Marine 9-74400
GLM 87630

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This kit is engineered for a range of OMC Stern Drive engines produced before the Cobra series.

Brand Model Rated HP Stroke Years OEM Part No. Notes
OMC V6 Stern Drive Various 4-Stroke 1980–1985 982946 Except Cobra models
OMC V8 Stern Drive Various 4-Stroke 1980–1985 982946 Except Cobra models
OMC 800 Series Stern Drive Various 4-Stroke 1980–1985 982946 Except Cobra models
OMC 3.8L Stern Drive Various 4-Stroke 1980–1985 982946 Except Cobra models
OMC 5.0L Stern Drive Various 4-Stroke 1980–1985 982946 Except Cobra models
OMC 5.7L Stern Drive Various 4-Stroke 1980–1985 982946 Except Cobra models

Technical Specs

Product Type
Gearcase Gasket and Seal Kit
Application
For lower gearcase application
Installation
Professional recommended
Dimensions
19.0" L x 12.0" W x 2.0" H
Weight
0.44 lb (0.2 kg)
Warranty
Standard manufacturer warranty

What’s in the Box

  • Complete Gasket and Seal Kit for OMC Lower Gearcase (Replaces 982946)

Installation Notes

  1. Drain the gearcase oil completely.
  2. Remove the propeller and mounting hardware.
  3. Unbolt and carefully separate the lower gearcase from the upper housing.
  4. Systematically disassemble the gearcase, keeping all parts in order.
  5. Remove all old seals, gaskets, and O-rings, taking care not to scratch any mating surfaces.
  6. Thoroughly clean all components and surfaces of old sealant and debris.
  7. Install the new seals and gaskets from the kit, lightly lubricating them with marine grease.
  8. Reassemble the gearcase, ensuring all components are correctly seated.
  9. Torque all bolts to the manufacturer's specified values.
  10. Refill the gearcase with the correct type and amount of marine gear lube.
  11. Check for leaks before and after test operation.

Troubleshooting & FAQ

Is this kit compatible with OMC Cobra models?

No, this kit is specifically for OMC Stringer stern drives from 1980–1985 and is not compatible with any OMC Cobra models.

What are the signs that my gearcase seals are failing?

Common signs include milky or water-contaminated gear oil, visible oil leaks around the propeller shaft or drain plugs, or a persistent need to top off the gear lube.

Does this kit fit both V6 and V8 OMC engines?

Yes, this kit is designed for the lower units on OMC V6, V8, 800 Series, and specific liter-designated engines (3.8L, 5.0L, 5.7L) within the 1980–1985 year range.

What is the difference between this and an OEM kit?

This is an aftermarket kit designed to meet or exceed original equipment manufacturer (OEM) specifications for fit, form, and function. It provides a cost-effective solution without compromising on quality or performance.

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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