The Top Gear Oil Seal (Old Model) is a vital sealing component designed for the gearbox of vintage Royal Enfield motorcycles, specifically those with the 4-speed right-shift cast-iron engine. It is installed behind the top gear (sleeve gear) to prevent primary or gearbox oil from leaking into the final drive or onto the chain area. Key Features Leak Prevention: Engineered to create a tight, high-pressure seal around the sleeve gear, ensuring oil stays within the gearbox housing. Heat & Friction Resistance: Made from high-quality nitrile rubber or specialized synthetic compounds that withstand constant rotational friction and high engine temperatures. Dual-Lip Design: Often features a dual-lip construction that keeps oil in while simultaneously preventing road dust and grime from entering the gearbox. Vintage Compatibility: Sized specifically for the output shafts of old-generation 350cc and 500cc Bullet and Standard models. Essential for Maintenance: Replacing this seal is a common part of gearbox overhauls to fix the “oil weep” typically found near the front sprocket area of older Enfields. Technical Specifications Feature Details Compatibility Bullet 350, Standard 350, Bullet 500 (Old 4-Speed Cast Iron Engines) Material Heavy-duty Nitrile Rubber with internal metal reinforcement Placement Gearbox Output / Sleeve Gear (Top Gear) Function Final Drive Oil Containment
