ULTRA 1PLUS 75W-90 Full Synthetic Gear Oil 1 Gallon — API GL-4, All-Season Protection

ULTRA 1PLUS SAE 75W-90 Full Synthetic Gear Oil (API GL-4) is a year-round, high-performance lubricant formulated to protect manual transmissions, transaxles, and differentials under heavy load and extreme temperatures.

Designed for passenger cars and light trucks, this 1-gallon jug of full synthetic 75W-90 meets API GL-4 and SAE J306 requirements. It combines advanced base oils with anti-scuff additives and friction modifiers to maintain a stable lubrication film, reduce wear, and support smooth shifting and limited-slip applications. The formulation focuses on thermal resilience, low-temperature flow, and long service life to lower maintenance intervals and preserve drivetrain components.

How does ULTRA 1PLUS 75W-90 protect gears and bearings?

The formulation creates a durable anti-wear film that resists breakdown under high torque and heavy loads, helping to prevent metal-to-metal contact. Additives reduce scuffing and inhibit deposit formation so gears and bearings run cleaner and last longer.

• Advanced anti-scuff chemistry for extreme-pressure protection
• Friction modifiers that reduce wear on synchronizers and gear teeth
• Stable film strength under sustained loads and shock loading
• Minimizes varnish and sludge buildup for cleaner internals

Will this oil work across seasons and temperatures?

Yes—this product meets SAE J306 viscosity requirements for all-season performance. It flows reliably at low temperatures for cold starts and retains viscosity at high operating temperatures to maintain a continuous protective film.

• Low-temperature fluidity for easier cold-weather shifting
• High-temperature stability to resist thinning during hot operation
• Oxidation resistance reduces viscosity increase and deposits
• Designed for a wide operating range in varied climates

Is ULTRA 1PLUS 75W-90 suitable for limited-slip differentials?

Yes—the oil includes friction modifier technology compatible with limited-slip and clutch-type differentials. It balances friction control and gear protection to maintain smooth differential operation without compromising wear resistance.

• Friction modifiers optimized for limited-slip engagement
• Compatible with passenger car and light truck limited-slip units
• Maintains consistent friction behavior over service life
• Reduces chatter while protecting gear surfaces

How does this choice reduce maintenance and prolong service intervals?

By resisting thermal and oxidative breakdown, the lubricant keeps viscosity and additive performance stable across long service periods. Cleaner internals and reduced wear translate to fewer repairs and extended component life, lowering total cost of ownership.

• Thermal and oxidation stability lowers oil degradation
• Anti-foam and rust inhibitors preserve lubricant function
• Reduced deposit formation simplifies inspections and flushes
• Helps extend the life of synchronizers, gears, and bearings

Who is this for: ULTRA 1PLUS SAE 75W-90 Full Synthetic Gear Oil is intended for mechanics, fleet operators, and individual vehicle owners who need a dependable GL-4 gear lubricant for manual transmissions, transaxles, and differentials in passenger cars and light trucks. Choose this 1-gallon option if you want a cost-effective, full-synthetic solution that supports limited-slip systems, offers robust protection under high-load conditions, and performs consistently across a wide range of temperatures.