Mercury MerCruiser Gasket & Oil Seal Kit – 8M0149926

Mercury MerCruiser Gasket & Oil Seal Kit – 8M0149926

Part Number: 8M0149926
Brand: Mercury Marine / Quicksilver
Official Product Type: Gasket & Oil Seal Kit – OEM
System: Engine Sealing / Gasket Set

About This Kit

This is a genuine Mercury OEM gasket and oil seal kit designed to restore proper sealing on Mercury MerCruiser and Quicksilver engines and drive assemblies. OEM seal kits use factory-spec materials — correct durometer rubber, correct lip geometry, and correct dimensional tolerances — to ensure a lasting seal that aftermarket alternatives often can't match. Use this kit during disassembly, resealing work, or any time a sealing surface is disturbed.

Compatible Applications

• Mercury MerCruiser sterndrive engines and drive assemblies where part number 8M0149926 appears on the parts diagram
• Mercury and Quicksilver outboard engines where this seal kit is specified by serial number range
• Any Mercury Marine assembly where the service manual calls for part number 8M0149926

Fitment for seal and gasket kits is diagram- and serial-number-specific. Always verify this part number against the Mercury parts diagram for your exact engine model and serial number before ordering.

Serial Number / Fitment Note

Mercury seal and gasket kits can vary significantly by production serial range — even within the same engine family. Locate your engine serial number on the transom bracket plate (outboards) or engine block tag (MerCruiser), then cross-reference against the Mercury parts diagram for your model to confirm 8M0149926 is the correct kit for your assembly.

Kit Contents

Includes the OEM gasket(s) and oil seal(s) as packaged by Mercury Marine for part number 8M0149926. Exact contents are defined by the Mercury parts diagram for your engine. Confirm kit contents against your service manual before beginning disassembly.

Service Interval / When to Replace

Replace gaskets and oil seals whenever the sealing surface is disturbed during service, or when you observe:

• Oil or fluid leaks at the sealed joint
• Hardened, cracked, or flattened seal lips
• Crushed or compressed gasket material that no longer provides a positive seal
• Any disassembly that requires breaking the original seal

Seals and gaskets are single-use components — always replace rather than reuse.

Installation Notes

• Clean all mating surfaces thoroughly before installation — old gasket material or sealant residue will cause leaks
• Replace all seals and gaskets disturbed during disassembly, not just the failed one
• Follow the Mercury service manual for correct orientation, lubrication requirements, tightening sequence, and torque specifications
• Do not reuse old seals or gaskets

Related Parts

• MerCruiser Oil Seal 14077
• Mercury MerCruiser Remote Oil Filter Adaptor Gasket 16779
• Mercury MerCruiser Quicksilver Oil Seal, Rear – Crankshaft Bearing Cap 14756
• Mercury MerCruiser Quicksilver Oil Filter Adapter Gasket 91892
• Mercury MerCruiser Quicksilver Gasket Set Oil Pan 810846T

Technical FAQ

Can I reuse the old gasket if it looks okay?
No. Gaskets and oil seals are single-use components. Once compressed or disturbed, they will not re-seal reliably. Always install new seals during any reassembly.

Do I need a sealant with this kit?
Follow the Mercury service manual for your specific assembly. Some joints require a thin bead of approved sealant in addition to the gasket; others are dry-fit only. Using sealant where it isn’t specified can cause as many problems as omitting it where it is.

What if my part number has been superseded?
Mercury periodically updates part numbers. If your dealer or diagram shows a different number, order the current number — it will be the correct replacement. Contact us if you need help cross-referencing.

Parts Desk Insights

Best use case: This kit is the right choice for technicians or experienced DIYers doing a full reseal on a MerCruiser engine or drive assembly where 8M0149926 appears on the diagram. It’s particularly valuable during a top-end rebuild, lower unit reseal, or any service job where multiple sealing surfaces are being disturbed at once — buying the kit is almost always more economical than sourcing individual seals.

Common mistakes: The most frequent error is ordering a gasket or seal kit by engine model alone without checking the serial number — Mercury changed seal specifications multiple times within the same engine family. Also watch for customers who only replace the leaking seal and skip adjacent seals that were disturbed during disassembly; this leads to a comeback leak within one season. Always recommend replacing everything in the kit as a set.