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FLASHSALE26

Gear Housing to Pivot Gasket – Fits OMC Cobra Stern Drive 2.3L-5.8L (Replaces 915840, 911836)

Regular price $12.38

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


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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 Gear Housing to Pivot Gasket is designed for OMC Cobra stern drives, fitting a wide range of engines from 1986 to 1993. It's compatible with 2.3-3.0L 4-cylinder (85-130 HP), 4.3L V6 (160-165 HP), and 5.0-5.8L V8 (185-240 HP) models, ensuring a precise seal between the gear housing and pivot connection.

It serves as a direct replacement for OMC part numbers 915840, 0915840, 911836, and 0911836, and interchanges with Sierra 18-2918, GLM 34730, Mallory 9-62650, and Barr OMC47-911836.

  • Engineered for direct replacement and easy installation.
  • Seals the gear housing to the pivot connection to prevent leaks.
  • Constructed from a durable paper/composite material for a reliable fit.

Part Number Matrix

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

Brand Part Number
OMC 915840 / 0915840
OMC 911836 / 0911836
Sierra 18-2918
GLM 34730
Mallory 9-62650
Barr OMC47-911836

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For OMC applications, this gasket fits various Cobra stern drive models produced between 1986 and 1993.

Brand Model Rated HP Stroke Years OEM Part No. Notes
OMC Cobra Stern Drive 85-130 4-Stroke 1986–1993 915840 2.3-3.0L 4-cylinder engines
OMC Cobra Stern Drive 160-165 4-Stroke 1986–1993 915840 4.3L V6 engines
OMC Cobra Stern Drive 185-240 4-Stroke 1986–1993 915840 5.0-5.8L V8 engines
OMC Cobra 2.5L 120 4-Stroke 1986 915840
OMC Cobra 5.7L 230 4-Stroke 1987 915840
OMC Cobra 2.3L 100 4-Stroke 1987–1990 915840
OMC Cobra 3.0L 130 4-Stroke 1988 915840
OMC Cobra 5.0L 200 4-Stroke 1988 915840
OMC Cobra 4.3L 175 4-Stroke 1989–1990 915840
OMC Cobra 5.8L 240 4-Stroke 1989 915840
OMC Cobra 4.3L 185 4-Stroke 1991 915840
OMC Cobra 5.0L 200 4-Stroke 1993 915840
OMC Stern Drive 584APLAMH 230-240 4-Stroke 1992 915840 5.8L V8

Technical Specs

Product Type
Gear Housing to Pivot Gasket
Installation
Direct replacement
Housing Material
Paper/Composite
Housing Color
Black
Dimensions
29 x 19 cm (approx. 11.4 x 7.5 inches)
Weight
0.11 kg (0.25 lbs)
Warranty
Varies by seller (typically 1 year against manufacturing defects)
Other Technical Attributes
Used to seal the gear housing to pivot connection in OMC Cobra stern drives

What’s in the Box

  • 1 x Gear Housing to Pivot Gasket (915840/0915840)

Installation Notes

  1. Disconnect the battery and follow all manufacturer safety precautions.
  2. Drain the gearcase lubricant completely into an approved container.
  3. Carefully disassemble the components required to access the gear housing to pivot connection.
  4. Remove the old gasket and thoroughly clean both mating surfaces. Ensure they are free of old gasket material, sealant, oil, and debris.
  5. Position the new gasket correctly onto the cleaned surface.
  6. Reassemble the stern drive components, tightening bolts to the manufacturer's specified torque in the correct sequence.
  7. Refill the gearcase with the recommended lubricant to the proper level.
  8. After reassembly, check for any leaks around the new gasket before and after running the engine.

Troubleshooting & FAQ

How do I know if this gasket will fit my engine?

This gasket is for OMC Cobra stern drives (1986–1993) across various engine sizes (2.3L to 5.8L). The best way to confirm fitment is to check your model and year against the compatibility table on this page. Also, verify that your current part number matches one of the cross-references like 915840, 911836, or Sierra 18-2918.

What are the signs of a failed gear housing gasket?

A common sign of failure is water intrusion into the gear lube (milky or creamy-looking oil) or gear lube leaking out of the stern drive unit. You may notice an oil sheen on the water around the drive or a consistent drop in your gear oil level.

Do I need to use sealant with this gasket?

This is a common question. Generally, modern gaskets like this one are designed to be installed dry on clean, flat surfaces. However, some mechanics prefer to apply a very thin layer of a non-hardening sealant. Always consult your specific engine's service manual for the official recommendation.

How often should this gasket be replaced?

This gasket does not have a set replacement interval. It should be replaced anytime the gear housing is separated from the pivot housing for service, or if you detect a leak in that area.

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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