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Start ShoppingCometic C9151 Twin Cam Transmission Gasket - Reusable AFM Gasket for Harley-Davidson 5-Speed
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Description
Ensure optimal performance and reliability for your Harley-Davidson Twin Cam 5-speed transmission with Cometic's purpose-built C9151 gasket. Engineered to withstand extreme heat and torque cycles, this reusable AFM gasket delivers unmatched sealing performance for power sports enthusiasts.
Key Features
- Reusable AFM Material: Non-metallic composite construction resists warping and maintains sealing integrity through repeated heat and torque cycles.
- Specifically Designed for Twin Cam 5-Speed: Precision-engineered fit for Harley-Davidson transmissions to prevent leaks and ensure proper operation.
- Heat and Torque Resistant: Advanced material formulation handles extreme engine conditions without degradation or failure.
- No Sealer Required: Eliminates need for messy sealants, simplifying installation and reducing maintenance.
- Green AFM Color: Visually distinct color aids in identifying correct gasket during installation.
Why Choose This Product
Cometic's C9151 gasket combines military-grade durability with user-friendly design. Its reusable construction saves costs compared to disposable gaskets, while the AFM material ensures consistent sealing under harsh operating conditions. Manufactured in the USA, this gasket is built to meet the rigorous demands of power sports applications, providing peace of mind for riders who demand top-tier performance from their motorcycles.
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Ensure optimal performance and reliability for your Harley-Davidson Twin Cam 5-speed transmission with Cometic's purpose-built C9151 gasket. Engineered to withstand extreme heat and torque cycles, this reusable AFM gasket delivers unmatched sealing performance for power sports enthusiasts.
Key Features
- Reusable AFM Material: Non-metallic composite construction resists warping and maintains sealing integrity through repeated heat and torque cycles.
- Specifically Designed for Twin Cam 5-Speed: Precision-engineered fit for Harley-Davidson transmissions to prevent leaks and ensure proper operation.
- Heat and Torque Resistant: Advanced material formulation handles extreme engine conditions without degradation or failure.
- No Sealer Required: Eliminates need for messy sealants, simplifying installation and reducing maintenance.
- Green AFM Color: Visually distinct color aids in identifying correct gasket during installation.
Why Choose This Product
Cometic's C9151 gasket combines military-grade durability with user-friendly design. Its reusable construction saves costs compared to disposable gaskets, while the AFM material ensures consistent sealing under harsh operating conditions. Manufactured in the USA, this gasket is built to meet the rigorous demands of power sports applications, providing peace of mind for riders who demand top-tier performance from their motorcycles.| SKU | GMBCA749B2 |
|---|---|
| MPN | C9151 |
| Brand | Cometic |
| Category | Gaskets/Seals |
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Featured Review
| Make | Model | Years |
|---|---|---|
| Harley-Davidson | Dyna models with Twin Cam 88 (5‑speed) | 1999-2005 |
| Harley-Davidson | Softail models with Twin Cam 88B (5‑speed) | 2000-2006 |
| Harley-Davidson | Touring models with Twin Cam 88 (5‑speed) | 1999-2006 |
Frequently Asked Questions
No. The C9151 is intended for Twin Cam models equipped with the earlier 5‑speed transmission. It does not fit 6‑speed Cruise Drive transmissions. Always match by year/model and transmission type.
Normally no. Cometic AFM/fiber gaskets are designed to be installed dry on clean mating surfaces. Only use sealant if specifically instructed by the Harley‑Davidson service manual for your exact model.
Cometic AFM gaskets are marketed as re‑usable in many applications, but best practice is to inspect it any time the cover is removed. If it is torn, crushed, or contaminated, replace it. For critical leak‑free service, many technicians prefer a new gasket each time.
Yes. The gasket is compatible with common transmission and primary lubricants, including synthetic oils, as long as they meet Harley‑Davidson specifications for your model.
No. It is a sealing gasket only and does not affect gear ratios or shifting characteristics when installed correctly.
Installation Guide
Difficulty
Medium
Est. Time
45 min
Tools Required
- Harley‑Davidson service manual for your model
- 1/4" or 3/8" drive ratchet
- Socket set (SAE) for transmission top cover bolts
- Inch‑pound or foot‑pound torque wrench (per service manual spec)
- Shop rags
- Plastic scraper or gasket remover (non‑metallic)
- Brake cleaner or solvent for mating surfaces
- Threadlocker (if required by OEM spec)
Pro Tips
- Dry‑fit the gasket first to confirm orientation and bolt hole alignment.
- Clean mating surfaces to bare metal and wipe with brake cleaner just before installation.
- Install bolts finger‑tight, then torque in a criss‑cross pattern in 2–3 stages to the factory spec.
- Inspect the shifter shaft seal and other transmission seals while the cover is off; replace if weeping.
- After the first ride, inspect for seepage around the cover and re‑check bolt torque if your service manual allows.
Common Mistakes to Avoid
- Over‑tightening transmission top cover bolts and crushing the gasket
- Using RTV or silicone sealant with a Cometic AFM gasket (not needed and can cause leaks)
- Not fully cleaning old gasket material from the case and cover surfaces
- Re‑using distorted or corroded bolts or washers
- Cross‑threading or tightening bolts in the wrong sequence
Comparison vs Stock/OEM
Functionally equivalent replacement for the OEM Harley‑Davidson transmission top cover gasket on Twin Cam 5‑speed models.
Improvements
- High‑quality AFM/fiber construction designed to maintain seal under repeated heat cycles
- Often more durable and re‑usable compared with many OEM paper gaskets
- Consistent thickness and cut quality for precise fit
Considerations
- Must be installed on clean mating surfaces with proper torque sequence
- Not interchangeable with gaskets for 6‑speed transmissions or other engine families
Durability & Warranty
Expected Lifespan
Typically lasts the service life of the transmission top cover service interval when installed correctly; replacement usually only needed when the cover is removed again or if disturbed.
Warranty
Subject to Cometic’s standard gasket warranty via retailer (no specific extended warranty details published).
Maintenance
No direct maintenance required; periodically inspect the transmission top cover area for seepage during routine service.
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