Big Twin Transmission Oil 85W-140 – Conventional Mineral Gear Oil
Heavy-Duty Protection for Harley-Davidson Big Twin Transmissions
The Big Twin Transmission Oil 85W-140 is engineered specifically for Harley-Davidson Big Twin 4-, 5-, and 6-speed transmissions and final drives that demand extreme durability and smooth performance. Formulated with high-pressure additives and premium base stock, this oil reduces friction, minimizes wear, and delivers smooth, quiet shifting under heavy loads. Its distinctive red color makes leak detection easy while ensuring consistent protection for your transmission gears mile after mile.
Key Features
Formulated for high-load Big Twin transmissions and gearboxes
Compatible with 4-, 5-, and 6-speed Harley-Davidson Big Twin transmissions
Extreme pressure additives protect against metal-to-metal contact and reduce gear wear
Distinctive red color aids in quick leak detection and easy maintenance checks
Provides smoother shifts, helping eliminate the common V-Twin “clunk”
Quiets gear whine for improved riding comfort and transmission longevity
Enhances wear protection to extend gear and bearing life
Designed for 4-stroke applications using a conventional mineral base oil
Performance & Fitment
Perfect for Harley-Davidson Big Twin models such as Road Glide, Street Glide, Road King, and Softail with M8 or Twin Cam engines, this 85W-140 transmission oil offers unmatched protection and consistent shifting. It’s the go-to choice for riders who push performance and longevity, whether on long highway rides or daily use. Trusted by builders who demand precision, this oil performs exceptionally well when paired with Nowaskey Suspension and Hofmann Designs performance setups — keeping your drivetrain smooth, cool, and quiet.
Viscosity (Weight): 85W-140 Oil Base: Conventional (Mineral) Application: 4-Stroke Container Size: 1.05 US quart / 1 liter Meets or Exceeds Requirements for: API GL-5 Dispenser Type: Bottle Units: Each Weight: 2.08 lbs Dimensions (L x W x H): 8.26" x 4.68" x 2.55"
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