What kind of oil goes in a rear diff?
The type of oil that goes in a rear differential (or rear diff) depends on the specific vehicle and manufacturer recommendations. Generally, a gear oil or hypoid gear oil is used in the rear differential to lubricate and protect the gears and bearings.
Understanding Rear Differentials
The rear differential is a crucial component in the drivetrain of a vehicle. It is responsible for transferring power from the transmission to the rear wheels, while also allowing the wheels to rotate at different speeds when turning. This differential movement is necessary to prevent binding and uneven tire wear.
Inside the rear differential, there are a set of gears and bearings that need to be properly lubricated to function effectively and prevent premature wear. The type of oil used in the rear diff can vary depending on the vehicle make, model, and year, as well as the specific design of the differential.
Recommended Rear Differential Oils
The most common types of oil used in rear differentials are:
- Gear oil: A specialized lubricant designed for the high-load, high-speed conditions found in differentials and other gear-driven components. Gear oils typically have a higher viscosity than engine oils.
- Hypoid gear oil: A type of gear oil specifically formulated for hypoid gear sets, which are commonly used in rear differentials. Hypoid gear oils have additional additives to protect against wear and provide better lubrication.li>
The exact oil specification required for your vehicle's rear differential can be found in the owner's manual or by consulting with your vehicle manufacturer. It's important to use the recommended oil type and viscosity to ensure proper lubrication and protection of the differential components.
Changing Rear Differential Oil
In addition to using the correct oil type, it's also important to change the rear differential oil at the recommended intervals specified by the vehicle manufacturer. Neglecting to change the oil can lead to increased wear and potential failure of the differential components.
When changing the rear differential oil, be sure to dispose of the old oil properly and refill the differential with the recommended amount and type of new oil. Consult your owner's manual or a professional mechanic if you're unsure of the proper procedure.
Can I use 75W90 instead of 75W80?
If both 75W80 and 75W90 are approved for your car, you have the choice. Basically, the gear oils do not differ much from each other. 75W90 has a higher kinematic viscosity than 75W80.
What is the difference between 80w90 and 75W90 gear oil?
When run under real-world line-haul conditions, the use of 75W-90 can improve the efficiency of a Class 8 axle by an average of 0.5% over an axle using 80W-90. Considering that axles themselves are 95% efficient, a gain of 0.5% is significant.
What fluid should never be used in a rear differential?
Never, under any circumstances, put engine oil in your differential. This will result in devastating damages to your engine. Engine oil is much different than gear oil, mostly it cannot withstand high pressure.
Which grade of oil is used in differential?
Separate differentials usually have higher pressure between metal parts than gearboxes and therefore need higher GL-rating. For example, most modern gearboxes require a GL-4 oil, and separate differentials (where fitted) require a GL-5 oil.
What fluid would most likely go in a rear differential?
Gear oil (e.g., SAE 75W-90, 75W-140, 80W-90, 80W-140, 85W-140) is the most common differential fluid. Some differentials use limited slip additives.
Which lubricant would one expect to be used in a rear differential?
Normally it will be an Extreme Pressure (EP) Gear Oil, typically EP80. However, some rear diffs such as limited slip diffs (LSD's) require a special LSD oil which will be specified by the diff manufacturer if fitted as an 'add on' for special use or by the vehicle manufacturer if fitted as OE.
Which is thicker 75W90 or 75W140?
So, the difference between "75W90" and "75W140" is that at operating temperature, the 75W140 will be considerably thicker than the 75W90 but at room temperature they will be about the same viscosity.
Is gear oil the same as rear differential fluid?
The differential fluid, also known as gear oil, is specifically formulated to lubricate and protect the gears and bearings within the differential housing. On the other hand, transmission fluid is responsible for lubricating and cooling the intricate components of your vehicle's transmission system.
What oil to use in rear differential?
75W90 GL-5 Gear Oil
The go-to gear oil for most differentials.
What can you use instead of gear oil?
Typically, semi-fluid greases such as NLGI #000 or #00 are recommended for small gearboxes that frequently are run to fail. This strategy simplifies maintenance practices by reducing the chance of a leak and the need to top up components.
