Sinclair Conventional Gear Oils

Industrial Lubricants and Greases

Conventional Gear Oils

Driveline designs are changing, and operating conditions are getting more and more severe. So, you need gear lubricants that keep pace, with exceptional load-carrying capability whenever extreme pressure and shock loads can be expected. Like the advance driveline gear oils developed by Sinclair, formulated to give you an effective balance of protection, toughness and endurance.

Benefits include:

Thermal degradation protection.

Oxidation reduction.

Reductions in both wear and corrosion.

Better shear stability.

Sinclair gear oils are designed for use on-highway passenger cars, SUVs, light- and heavy-duty trucks, buses, and vans. Off-highway industries, such as construction, mining, quarrying and agriculture engines are also ideal for Sinclair Gear oils.

However, Sinclair Gear oils are not recommended/intended for applications requiring API GL-4 level performance or automatic, manual or semiautomatic transmissions for which engine oil or automatic transmission fluids are recommended. For more information, please consult your owner’s handbook for the specific OEM application requirements for your vehicle or equipment.

Formulated to Combat Friction and Wear

Our advanced formulation features a molecular bond that creates a shield designed to reduce friction and wear.

Holds Up Even Under Extremes

Not even the harshest cold or most punishing heat can keep Sinclair Gear Oils from outstanding protection against pressure, power density, micropitting or oxidation, shrinking sump sizes or separation of air and water.

Sinclair Conventional Gear Oils: Performance You'll Notice

Sinclair Conventional Gear Oils are specifically engineered and formulated to give you:


Against load, shear and shock.


Excellent protection against wear and corrosion.


Long-lasting thermal stability means longer life for gear, bearings and seals.

Typical Properties

Viscosity Grade 80W-90 85W-140
Brookfield Viscosity at -26°C, cP ASTM D2983 92,000 -
Color ASTM D1500 7 8
Flash Point °C ASTM D92 224 235
Flash Point °F ASTM D92 435 455
Gravity, °API ASTM D287 27.76 25.69
Pour Point °C (°F) ASTM D5950 -33°C (-27°F) -18°C (0°F)
Specific Gravity @ 60°F (15.6°C) ASTM D4052 0.8885 0.9002
Viscosity @ 100°C cSt ASTM D445 13.98 26.39
Viscosity @ 40°C cSt ASTM D445 130.9 347.7
Viscosity Index ASTM D2270 104 100
Brookfield Viscosity at -12°C, cP ASTM D2983 - 55,000

Industry/OEM Approvals

Title 80W-90 85W-140
API GL-5 Meets Requirements Meets Requirements
Limited Slip Top Off/Service Fill Suitable for Use Suitable for Use
Mack GO-J, GO-H, GO-G Meets Requirements Meets Requirements
MT-1 Meets Requirements Meets Requirements
SAE J2360, MIL-2105E/F Meets Requirements Meets Requirements