75W90 Synthetic Rear End Oil Qt. Valvoline

The 75W90 Synthetic Rear End Oil Qt. by Valvoline is purpose-built for differential and limited-slip rear end assemblies in high-performance and heavy-duty vehicles. This synthetic formulation is engineered for mechanics and enthusiasts who demand superior protection under extreme load conditions, whether you're running a stock truck, towing heavy trailers, or pushing modified differentials on the street or track. A quart container provides convenient portioning for top-ups, drain-and-fill service intervals, or as a backup supply for serious builders.

The 75W90 weight grade delivers optimal film strength and gear protection across a wide temperature window, preventing wear on hypoid gearsets while maintaining smooth operation during cold starts and high-speed highway runs. Valvoline's synthetic base stock resists thermal breakdown and shear better than conventional mineral oils, extending drain intervals and protecting against rust and corrosion inside the housing. The formulation includes friction modifiers that enhance performance in limited-slip and locking differentials without causing chatter or excessive drag on open applications, making it a versatile choice for various rear end configurations.

This product suits truck owners, off-road builders, street performance enthusiasts, and mechanics performing routine maintenance or differential rebuilds. Verify your vehicle's factory specification or consult your owner's manual to confirm 75W90 compatibility—many modern differentials call for this grade, while some Ford and Chrysler models may require 80W140 or proprietary formulations. When converting to synthetic, drain the old oil completely, inspect your differential cover gasket and drain plug for leaks, and confirm fill capacity before topping off with this quart container.