AMSOIL 100% SYNTHETIC V-TWIN PRIMARY FLUID

AMSOIL 100% Synthetic V-Twin Primary Fluid is a purpose-built primary chaincase lubricant that delivers consistent clutch feel, prevents slip, and protects the chain, gears, and compensator bearing in Harley-Davidson, Triumph, and pre-2013 Indian motorcycles.

The primary chaincase in a V-twin is a demanding environment. It houses the clutch pack, primary chain, compensator, and sprocket assembly, all sharing the same fluid. A generic oil or multi-purpose formula can lead to clutch slip, inconsistent engagement, and accelerated wear on the compensator bearing. Riders dealing with notchy shifts into neutral, grabby clutch engagement, or premature chain wear often trace the problem back to using the wrong fluid in the primary.

CONSISTENT CLUTCH FEEL AND SMOOTH ENGAGEMENT
AMSOIL Synthetic V-Twin Primary Fluid is formulated with a balanced additive system designed specifically around wet clutch operation. It passes the JASO T 904 friction test at both MA and MA2 levels, confirming it maintains the friction characteristics a wet clutch needs for predictable engagement. That translates to confident takeoffs at a stoplight without killing the engine and easier neutral-finding in stop-and-go traffic. Riders running Rekluse auto-clutch systems, which specifically call for JASO MA2-rated fluids, can run this product with confidence.

PREVENTS CLUTCH SLIP UNDER LOAD
Clutch slip is more than annoying. It robs power, generates excess heat, and accelerates plate wear. This fluid's superior load-holding capacity resists the compression forces between clutch plates during hard acceleration and high-torque situations. Whether pulling away from a stop on a loaded bagger or rolling on the throttle through a highway merge, the clutch grabs and holds.

PROTECTS THE COMPENSATOR, CHAIN, AND GEARS AGAINST WEAR
The primary chaincase sees significant shock-loading, especially through the compensator assembly. AMSOIL V-Twin Primary Fluid delivers a Four-Ball Wear Test scar diameter of just 0.37 mm (ASTM D4172, 40 kgf, 150°C, 1800 rpm, 1 hour), reflecting a heavy dose of anti-wear additives and strong film strength under extreme pressure. That protection extends to the primary chain and sprockets, reducing the kind of wear that eventually leads to chain stretch and compensator noise.

RESISTS THERMAL BREAKDOWN IN EXTREME HEAT
Primary chaincases run hot, especially on air-cooled V-twins in summer traffic. This fluid features a flash point of 238°C (460°F) and a fire point of 258°C (496°F), with a thermally stable synthetic base that resists breakdown at sustained high temperatures. A viscosity index of 144 means the fluid maintains its protective film across a wide temperature range, from a cold morning startup to extended highway cruising in triple-digit heat.

MAXIMIZES ENERGY EFFICIENCY AT STARTUP
With a pour point of -35°C (-31°F), this fluid flows readily in cold conditions, reducing drag on the primary chain and clutch pack during cold starts. Less drag means smoother shifts at startup and less energy wasted before the bike reaches operating temperature.

SPECIFICATIONS AND COMPATIBILITY
AMSOIL Synthetic V-Twin Primary Fluid meets JASO MA/MA2 friction standards. It is designed as a direct replacement for OEM primary chaincase fluids used in Harley-Davidson Big Twin models (Sportster models use a shared sump and do not have a separate primary), Triumph V-twin models, and pre-2013 Indian motorcycles. It is Warranty Secure, meaning it will not void your motorcycle's factory warranty, and is backed by the AMSOIL Limited Warranty.

SERVICE LIFE
AMSOIL recommends Synthetic V-Twin Primary Fluid for up to 10,000 miles (16,000 km) or one year, whichever comes first.