Toyota Hypoid Gear Oil SX GL-5 85W-90: What It Is and When to Use It
The short answer
Toyota Hypoid Gear Oil SX is Toyota's branded gear lubricant rated API GL-5 with an SAE 85W-90 viscosity grade. It is intended for hypoid gear sets, the type commonly used in differentials. It suits your vehicle only if the owner's manual or service information for your exact model year, market, trim and drivetrain calls for a GL-5 85W-90 oil in that component. If your manual specifies a different grade, a different service class, or a limited-slip-specific fluid, follow the manual instead.
What the label means
Term | Meaning; Hypoid | A gear design with offset, spiral-cut teeth that is commonly used in differentials. The teeth slide against each other under heavy load, so the oil needs strong anti-wear protection. API GL-5 | A service classification for gear oils meant for hypoid gears under severe conditions. These oils carry a high level of extreme-pressure additives. SAE 85W-90 | A multigrade viscosity rating. The 85W part describes cold-temperature behavior, and the 90 describes viscosity at operating temperature. SX | Toyota's product designation within its gear oil range. The supplied material does not define what distinguishes SX from Toyota's other gear oils.
Conditions that change the answer
Manual transmissions: Some manual gearboxes specify GL-4 rather than GL-5. GL-5's additive level may not suit every transmission design, so do not assume a differential oil is right for a gearbox. Limited-slip differentials: Some limited-slip units need an oil formulated for them or a friction-modifier additive. Check whether your vehicle has a limited-slip differential and what fluid the manual specifies for it. Transfer cases and front differentials: On four-wheel-drive and all-wheel-drive models, these components may call for a different fluid than the rear differential. Confirm each one separately. Market and model year: Toyota's fluid specifications can vary between regions and between generations of the same model name. Use the documentation for your specific vehicle. Climate and use: Some manuals list alternative viscosity grades for very cold climates or for heavy towing. Check whether your manual offers this.
How to confirm fitment
Find the lubricant specification table in your owner's manual. It is usually in the maintenance or specifications section. Locate the entry for the specific component you are servicing, such as the rear differential, front differential, transfer case or manual transmission. Check that the listed service class is GL-5 and the viscosity is 85W-90. Also note any mention of a limited-slip-specific fluid. If the manual is missing or unclear, give a Toyota dealer parts department your VIN and ask them to confirm the correct fluid and fill capacity.
Information not covered here
No vehicle fitment list, part numbers, container sizes, fill capacities, change intervals, prices, availability or test data were supplied for this article, so none are stated. For those details, rely on Toyota's service documentation or a dealer lookup for your specific vehicle.