Royal Purple MAX GEAR 75W-140 Gear Oil 1-Quart Pack of 6 — Full-Synthetic, Limited-Slip Protection

Royal Purple MAX GEAR 75W-140 is a full-synthetic, limited-slip-capable gear oil in 1‑quart bottles, sold as a pack of six for heavy-duty and performance differentials.

Built for modern passenger cars, trucks, and performance vehicles that demand high-load protection, this 75W-140 formulation combines synthetic base stocks with friction modifiers to support limited-slip differentials and hypoid gears. The thicker 75W-140 viscosity at operating temperature gives improved film strength under heavy load and high-temperature conditions compared with lighter gear oils, while the synthetic base helps resist shearing and oxidation over time.

How does MAX GEAR 75W-140 protect my differential under load?

MAX GEAR 75W-140 is engineered to maintain a robust lubricating film between gear teeth under heavy torque and shock loads. That film reduces metal-to-metal contact, minimizing wear and extending gear life in towing, hauling, and spirited driving situations.

• 75W-140 viscosity provides high-temperature film strength
• Synthetic base oils reduce viscosity loss from shear
• Additive package enhances extreme-pressure protection

Is this oil suitable for limited-slip differentials and what does the additive do?

This product includes a friction modifier compatible with many limited-slip units to reduce chatter and improve engagement. The additive helps the clutch surfaces inside limited-slip differentials operate smoothly while still transmitting torque as designed.

• Formulated with limited-slip additive for clutch-type diffs
• Balances traction and reduced noise/harsh engagement
• Compatible with many OEM limited-slip requirements — always confirm with your manual

How often should I change the gear oil and can I mix it with other oils?

Change intervals depend on vehicle use, OEM recommendations, and operating conditions; severe duty (towing, racing, off-road) usually requires more frequent changes. While synthetic gear oils are often compatible with conventional oils, mixing reduces performance benefits — for best results, use Royal Purple MAX GEAR 75W-140 exclusively when possible and follow your owner’s manual.

• Follow the vehicle manufacturer’s maintenance schedule
• Severe service may require shortened drain intervals
• Avoid mixing brands/types to preserve additive effectiveness

Will this gear oil work in my car, truck, or performance build?

MAX GEAR 75W-140 is intended for hypoid gears and differentials that call for a 75W-140 viscosity and require limited-slip compatibility. Always verify your vehicle’s specifications before use, including API or OEM approvals listed in the manual.

• Designed for hypoid and conventional differentials needing 75W-140
• Works for many light trucks, SUVs, and performance rear-ends
• Check manufacturer specs for compatibility and approvals

Who is this for: Royal Purple MAX GEAR 75W-140 (1 qt, pack of 6) is aimed at owners and technicians who run heavy-duty or performance-driven differentials—towing enthusiasts, off-roaders, track-day drivers, and fleets—who want a stable synthetic gear oil with limited-slip capability and consistent high-temperature protection. It’s ideal when you need multiple quarts on hand for service or multiple vehicles, and when following the vehicle manufacturer’s recommendations for viscosity and additive needs is a priority.

• Features: For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.