Gear Oil Differential - JAX Service Inclusion

The short answer is no. The differential oil and transmission fluid are not the same. While both are types of lubricants used in your vehicle's drivetrain, manufacturers designed them for different purposes and have other properties.

Here are some of the main differences in the makeup of transmission fluid and differential oil:

• Viscosity: Differential oil typically has a higher density than transmission fluid because the differential system's gears and bearings are subject to higher stress levels and pressure. The thicker oil provides better protection against wear and tear.
• Additives: Both transmission fluid and differential oil contain additives, but the specific additives are different. Transmission fluid contains friction modifiers and anti-wear agents. In contrast, differential oil has special additives that protect against extreme pressure, heat, and corrosion.
• Composition: Differential oil made with mineral, synthetic, or a blend of both. Transmission fluid, on the other hand, can be made from various base oils, such as mineral oil, synthetic oil, or a combination of both, and may contain additional ingredients such as detergents, dispersants, and seal conditioners.
• Purpose: the primary purpose of differential oil is to lubricate and protect the gears and bearings in the differential system, while the primary function of transmission fluid is to lubricate and cool the moving parts of the transmission system and to facilitate the smooth shifting of gears.

Suppose the level of differential oil is low. In that case, it can have several adverse effects on the performance and longevity of the differential system.

Here are some of the potential consequences of low differential oil:

• Reduced fuel efficiency: the differential system is crucial in transferring power from the engine to the wheels. Low oil levels can increase fuel consumption if the system is not operating efficiently.
• Increased friction and wear: Differential oil lubricates the gears and bearings in the differential system, reducing friction and wear on the moving parts. If the oil level is low, there may not be enough oil to adequately lubricate the gears and bearings, leading to increased friction and wear, which can cause damage and shorten the lifespan of the differential system.
• Increased noise and vibration: Low differential oil levels can also lead to increased noise and vibration in the differential system. This is because there may not be enough oil to cushion and dampen the sound and vibrations generated by the gears and bearings.

Suppose the differential gear oil in a vehicle is old, contaminated, or degraded. In that case, it can lead to various adverse symptoms that permanently damage the metal components, leading to costly repairs and replacements. To avoid damaging your differential system, here are some of the common symptoms to look out for:

• Overheating: Differential oil also helps reduce heat generated by the moving parts in the differential system. When there are low oil levels, there is not enough oil to absorb and dissipate the heat, which can cause the differential to overheat and potentially seize up.
• Burnt oil smell: The smell signifies that the diff is overheating due to improper lubrication due to old, expired or low oil providing improper lubrication.
• Whirring noises: A symptom of a bad differential oil is humming, whining, or howling strange noises, indicating there may not be enough oil to adequately lubricate the gears and bearings, leading to increased friction and wear.
• Difficulty shifting gears: Bad differential gear oil can also make it challenging to shift gears, particularly in manual transmissions, as the friction and wear on the gears and synchronisers increases.

Changing the differential oil is essential to maintaining the smooth running of your differential and preventing costly repairs. Over time, if you don't change the differential oil regularly, the oil breaks down and becomes contaminated with dirt, debris, and metal shavings from the gears, leading to increased friction, wear, and overheating. This can cause the differential to make noise, vibrate excessively, and reduce fuel efficiency, eventually leading to the failure of the differential system.

The recommended service interval for differential gear oil varies depending on the make and model of the vehicle, as well as the type of engine. As a general guideline, differential oil is typically replaced every 50,000 to 80,000 kilometres or every 2 to 3 years, whichever comes first. However, suppose you frequently engage in heavy-duty driving, such as towing or off-roading. In that case, we recommend changing the oil regularly, typically every 25,000 kilometres or every year.

It's essential to consult your vehicle's owner's manual or check with a qualified mechanic for the manufacturer's specific recommendations for your particular vehicle. If unsure, chat with your local JAX expert for professional advice.

Manufacturers designed differential and gearbox oil to have distinct compositions and properties. Here are some of the differences in the makeup of differential oil and gearbox oil:

• Viscosity: Differential oil has a higher viscosity than gearbox oil, making it thicker and more flow-resistant. This helps to provide better lubrication and reduce wear in the high-pressure, high-temperature environment of the differential system. In contrast, gearbox oil has a lower viscosity, allowing for smoother shifting and improved fuel efficiency.
• Additives: Differential and gearbox oil contain additives to improve performance and protect against wear, corrosion, and oxidation. However, the specific additives used in each type of oil can vary. For example, differential oil may contain friction modifiers to reduce friction and improve fuel efficiency. In contrast, gearbox oil may contain detergent additives to help clean and prevent the buildup of deposits in the transmission system.
• Composition: Differential oil is typically formulated using mineral oil or synthetic base oils, while, conversely, gearbox oil can be formulated using mineral oil, synthetic oil, or a blend of the two. The specific composition of the oil can affect its performance, such as its ability to withstand high temperatures or resist oxidation.