Syiono Primary Cover Gasket Kit for Harley Dyna & Twin Cam Softail 1999-2006 Complete Seal & Clutch Set

Syiono's primary cover gasket kit is a complete replacement set designed to restore a leak-free primary and clutch area on 1999–2005 Harley Dyna and 1999–2006 Twin Cam Softail models.

This gasket and seal kit collects the most commonly replaced primary cover parts into one package so you can remove, service, and reinstall the primary cover and derby plate without searching for individual pieces. It includes O-rings, oil seals, foam gaskets and the derby/clutch cover gasket sized for Twin Cam 88" and 95" engines. The components are manufactured from materials selected to match OEM fit and function for a reliable service repair.

What parts are included and why do they matter?

The kit brings together the seals and gaskets you'll typically replace during a clutch or primary cover job. Using fresh gaskets and seals prevents oil seepage and helps maintain proper clutch and primary chain lubrication.

• 11147 O-ring for proper sealing at specified interfaces
• 12052A and 12066 oil seals to stop shaft and bearing leaks
• 25416-70 or 25416-99 derby/clutch cover gasket made for Twin Cam 88" and 95" models
• Inspection foam gasket (60567 series) and primary foam gasket (60539-94) for tight coverage

Which Harley models and years is this compatible with?

This Syiono kit is tailored to the era of Harley engines that share similar primary and derby cover layouts. Confirm the year and engine type before ordering to ensure correct fitment.

• Compatible with Harley Dyna models from 1999 through 2005
• Compatible with Twin Cam Softail models from 1999 through 2006
• Fits Twin Cam 88" and 95" primary/derby configurations

How will using this kit affect a primary or clutch service?

Installing all new seals and gaskets during a primary cover removal reduces the risk of leaks and eliminates the need for repeat disassembly. The comprehensive set saves time and ensures each contact surface has the correct replacement part.

• Reduces post-service oil seepage at cover joints and shafts
• Prevents contamination of clutch components from leaking oil
• Streamlines maintenance by supplying needed parts in one kit

Are these parts OEM or aftermarket, and what material quality can I expect?

Syiono offers aftermarket components engineered to match the original geometry and sealing properties. Materials are selected for durability and resistance to oil, heat, and vibration common in primary housings.

• Foamet inspection and primary gaskets designed for conforming seals
• Oil seals and O-rings molded to resist common service temperatures and fluids
• Derby/clutch cover gasket cut to match Twin Cam cover bolt pattern

Who is this for: This kit is intended for motorcycle owners, independent mechanics, and restoration shops working on late‑1990s to mid‑2000s Harley Dyna and Twin Cam Softail bikes. It’s especially useful when you plan a clutch service, primary inspection, or derby plate removal and want a single, organized set of replacement seals and gaskets to ensure a proper reseal.