COMETIC SKU: 68-10306F5

Cometic M8 Molded Rubber Primary Housing Gasket - Harley Milwaukee-Eight

$120.000,00
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About Cometic

Cometic Gasket manufactures multi-layer steel head gaskets and complete gasket kits in Concord, Ohio. On a built V-twin running higher compression or a big-bore kit, the MLS head gasket is what keeps the top end sealed — which is why Cometic is the default spec on so many engine builds.

When servicing your Milwaukee-Eight primary, a reliable gasket is non-negotiable for preventing leaks and ensuring proper function. This Cometic molded rubber primary housing gasket is engineered as a direct replacement, offering a robust seal for your Harley. It's built to OEM specifications, providing confidence in its fitment and performance.

Why riders pick this

  • Molded rubber construction for superior sealing
  • OEM-spec replacement for Milwaukee-Eight engines
  • Direct fit to the primary housing
  • Designed to prevent primary oil leaks

The Cometic molded rubber primary housing gasket is a high-quality replacement designed specifically for Harley-Davidson Milwaukee-Eight (M8) engines. Its molded rubber construction provides a superior and more durable seal compared to standard paper gaskets, effectively preventing oil leaks from your primary cover. This gasket is a direct-fit component, making installation straightforward for riders performing their own maintenance or upgrades.

Enhanced Sealing for M8 Primaries

  • Molded rubber construction for improved durability and seal integrity
  • Direct replacement built to OEM specifications for M8 engines
  • Ensures a precise fit to the primary housing
  • Helps prevent oil leaks from the primary cover

Reliable for Maintenance and Upgrades

Whether you're swapping clutches, inspecting your primary drive, or simply replacing a worn-out gasket, this Cometic primary housing gasket delivers the performance and reliability you expect. It's an essential part for any Milwaukee-Eight owner looking to maintain their bike's integrity and avoid messy oil leaks. Trust Cometic for components that stand up to the demands of your V-twin.

Specifications

  • Brand: Cometic
  • Manufacturer Part #: C10306F5
  • Length: 7 in
  • Width: 6 in
  • Height: 0.05 in
  • Weight: 1 lbs

Common questions

Is this primary gasket compatible with Twin Cam engines?

No, this Cometic gasket is specifically designed for Milwaukee-Eight (M8) engines. Twin Cam models require a different part number and gasket design.

Is this an OEM Harley-Davidson gasket?

This is a Cometic-manufactured replacement gasket that is built to meet or exceed OEM specifications for Harley-Davidson part #257010, ensuring factory-level fitment and sealing performance.

What tools are needed to install this gasket?

Standard hand tools for primary cover removal, along with a gasket scraper for surface preparation, are typically sufficient for installing this primary housing gasket. No specialized tools are required.

Ordering from Vtwinbikers

  • Brand new, sourced through authorized US distribution — never used, never grey-market.
  • Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
  • Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
BRANDCometic
TYPEGaskets/Seals
SKU68-10306F5
WEIGHT1.0 lb
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
CUSTOMER REVIEWS
4.87
15 RATINGS
5★ 13
4★ 2
3★ 0
2★ 0
1★ 0
✓ VERIFIED
Jan 16, 2020

Almost identical to OEM. Good fit. I did miss that they are sold as each and not as a pair. Small detail and my fault but it did slow my project down a bit.

— Anonymous
✓ VERIFIED
Oct 18, 2021

Great seals and gaskets do the job once when you use quality gaskets

— Anonymous
✓ VERIFIED
Sep 26, 2019

Seal good and I haven't had any issues..

— Anonymous
✓ VERIFIED
Jun 27, 2025

It worked like it was suppose to, delivery was quick. <br />Pleased.

— Lloyd S
✓ VERIFIED
Dec 19, 2023

Just what I needed

Needed these when changing out intake manifold. They worked perfect for my ‘03 sporty.

— Carlos L
✓ VERIFIED
Jun 12, 2023

Cometic from here on out

These seals are the only ones I'll use. others came close but, for me, these are best.

— Vincent S