Rear Diff Fill Tank 12an w/Vented Cap

The Rear Diff Fill Tank 12AN with Vented Cap is a precision fluid management component engineered for serious automotive enthusiasts and performance builders who demand reliable differential lubrication systems. This KEVKO component addresses a critical gap in modified vehicle builds: maintaining proper differential fluid levels and temperature control without relying on factory fill ports that become inaccessible after suspension modifications, custom exhaust work, or tight engine bay configurations. Whether you're upgrading a drag racing platform, street performance build, or off-road rig, this auxiliary fill tank ensures consistent differential servicing and prevents overfill conditions that compromise gear protection.

Constructed with KEVKO's manufacturing precision, the Rear Diff Fill Tank features a 12AN port configuration that integrates seamlessly into custom hydraulic and lubrication circuits. The vented cap design allows atmospheric pressure equalization during thermal cycling, preventing vacuum formation and ensuring stable fluid levels as differential temperatures fluctuate under load—a critical consideration during sustained high-horsepower operation or towing applications. The compact 7.7 x 3.4 x 10.05-inch footprint and lightweight 1.17-pound construction enable flexible mounting in constrained engine bays without adding rotational mass or interference with suspension geometry. The 12AN fitting standard ensures compatibility with industry-standard braided hose and quick-disconnect couplers for clean, leak-free connections.

This fill tank benefits high-performance drag racers, trail riders, and dedicated street builders who've relocated differentials, installed custom chassis components, or require remote fluid monitoring during tuning sessions. Professional mechanics and suspension shops routinely specify KEVKO components for restomod projects and competition vehicles where stock cooling systems and fill locations no longer apply. Installation pairs naturally with custom differential coolers, transmission fluid lines, and integrated lubrication upgrades—especially on IRS conversions, rear-end swaps, or extensively modified platforms. The vented design accommodates both synthetic and conventional gear oils, making it equally valuable for street cruisers and track-only machines.