BIGLKNM Primary Gasket Kit for Harley Twin Cam 1999–2006 Dyna/Touring — Full Seal Set with Silicone Gasket & Oil/Mainshaft Seals

If your Harley shows oil seepage from the primary cover or you’re doing a clutch or primary-service job, this kit supplies the seals and gaskets needed to rebuild the primary assembly to factory-style fit. The set includes the primary cover gasket, derby and inspection gaskets, an O-ring, oil and mainshaft seals, plus locating screw gaskets, all made to resist engine heat and oil exposure.

What parts are included and do they match OEM numbers?

The kit contains every routine primary-seal component required for a full cover service: primary cover gasket, inspection cover gasket, derby cover gasket, O-ring, oil seal, mainshaft seal and two locating screw gaskets. The parts correspond to common OEM references to simplify fitment checks.

• Primary cover gasket and inspection cover gaskets for a complete seal
• Derby cover gasket for clutch access and O-ring for tight mating
• Mainshaft and oil seals for rotating shafts
• Locating screw gaskets to prevent fastener area leaks
• Referenced OEM numbers: 12052A, 12066, 25416-99C, 34901-94(A/B/C), 34906-85(A/B/FM), 11147

How does the material hold up under riding conditions?

BIGLKNM uses a ribbed silicone-based compound for the primary cover gasket and durable sealing materials for the oil and mainshaft seals. These materials are chosen for oil resistance and thermal stability so they maintain sealing performance through normal engine cycles and road conditions.

• Ribbed silicone-style primary gasket for improved compression and seating
• Oil- and heat-resistant seals to withstand crankcase temperatures
• Factory-style O-ring and screw gaskets to reduce leak paths

Will this kit fit my Harley Dyna or Touring model?

The kit is built for Harley-Davidson Twin Cam engine models from 1999 through 2006 — primarily Dyna and Touring families that share the same primary cover geometry. Always cross-check the listed OEM numbers and your bike’s year and engine type before purchase to ensure match.

• Compatible years: 1999–2006 Twin Cam engines
• Designed for Dyna and Touring models with corresponding primary cover layout
• Compare part references on your service manual or existing gaskets prior to installation

What’s included in the package and is installation straightforward?

The box ships ready with all gaskets and seals needed for a standard primary cover rebuild, so you won’t need to source additional small parts. Installation follows typical primary-cover procedures; basic mechanical experience and the right torque specs are recommended to avoid leaks.

• Package includes: 1 O-ring, 1 oil seal, 1 mainshaft seal, 2 locating screw gaskets, 1 derby cover gasket, 1 primary cover gasket, 1 inspection cover gasket
• Installation requires primary cover removal, cleaning, and proper torqueing of fasteners
• Replacement is best performed with service manual guidance or professional help

Who is this for: Riders and home mechanics who own 1999–2006 Harley Twin Cam Dyna or Touring motorcycles and need a full primary cover seal replacement during routine maintenance, clutch work, or to stop oil seepage. The kit is aimed at people seeking an OEM-referenced, complete gasket set that covers all the common sealing points in the primary assembly, whether doing a DIY rebuild or preparing the bike for professional installation.