ULTRA 1PLUS SAE 75W-90 Full Synthetic Gear Oil 6-Quart — API GL-5 MT-1, Limited-Slip Protection

This 6-quart pack of full synthetic SAE 75W-90 gear oil combines extreme-pressure additives, friction modifiers for limited-slip differentials, and thermal stability to help extend gear and bearing life in a wide range of passenger cars, light trucks, and off-road equipment. It meets API GL-5 and MT-1 specifications and is engineered for dependable cold-flow performance and oxidative resistance across seasonal conditions.

How does ULTRA 1PLUS protect gears under heavy load?

The formula includes anti-scuffing extreme-pressure agents that form a robust lubricating film under shock loading and high torque. That film reduces metal-to-metal contact and helps prevent pitting and wear during severe service.

• Anti-scuffing additives that resist gear tooth damage
• Stable film strength under high torque and shock loads
• Reduces maintenance needs by extending gear and bearing life

Will this oil work in limited-slip differentials without noise or chatter?

Yes—ULTRA 1PLUS contains dedicated limited-slip (LS) additives and friction modifiers to minimize differential chatter and ensure smooth torque transfer. The result is consistent limited-slip performance across varied driving conditions.

• LS chemistry tuned to prevent engagement noise in clutch-type differentials
• Smooth, predictable torque transfer for cornering and traction situations
• Compatible with systems specifying GL-5/MT-1 performance

How does the 75W-90 synthetic blend perform in cold and hot climates?

The SAE 75W-90 full synthetic base delivers reliable cold-start flow and maintains protective viscosity at elevated temperatures. Its oxidative and thermal stability resists varnish and foaming, helping preserve lubricating properties over extended drain intervals.

• Excellent low-temperature pour and pumpability for cold starts
• Resists oxidation and varnish for longer service life
• Maintains viscosity to protect gears at high operating temperatures

Is this available in other sizes or for fleet use?

While this listing covers the convenient 6-quart pack for individual servicing, the ULTRA 1PLUS formulation is also offered in larger containers for shops and fleets. The bulk options reduce per-unit cost for frequent service on multiple vehicles or heavy-use equipment.

• 6-quart packs ideal for one-vehicle differential or axle service
• Bulk pails available for shops and fleet maintenance needs
• API GL-5 and MT-1 ratings suitable for a wide range of gearboxes

Who is this for: ULTRA 1PLUS SAE 75W-90 Full Synthetic Gear Oil is designed for owners, mechanics, and fleet managers who need a high-performance, limited-slip-capable gear lubricant that performs across seasons. It fits light- and medium-duty differentials and axles requiring API GL-5 or MT-1 specifications, and is a practical choice for anyone seeking extended gear protection, reduced maintenance, and consistent limited-slip operation.