How Often Should Differential Fluid Be Changed?

Differentials play a large yet mostly forgotten role in our vehicles, allowing each wheel to rotate at its own speed when going over rough terrain or around corners. When taking turns, the outside wheels will need to rotate slightly further than the inside wheels. Think of an Olympic running track, where the inside lanes are shorter than the outside ones. The vehicle needs to compensate for this difference in distance through the use of a differential. Differentials allow for this independent rotation, maximizing the traction from the vehicle around turns and uneven terrain, and preventing uneven tire wear. 

What is Differential Fluid?

Differentials use a complex set of gears to accomplish this, requiring lubrication to keep the gears rotating smoothly similar to the oil that does the same for our engines. 

By minimizing the friction within the differential, differential fluid keeps the temperature in check. Without this lubrication, the many metal gears and components would encounter high friction, causing a dangerous build-up of temperature and potential failure of the differential.

Why Do I Need to Change Differential Fluid?

Over time, the differential fluid will begin to collect contaminants and degrade from the heat of the differential. This creates a cycle of damage to your fluid, as the degraded and burnt fluid will lose some of its lubricative properties, leading to further friction and heat to cause fluid degradation and problems within your differential. This process is sometimes referred to as “thermal runaway”. Damaged fluid in this high-friction environment can shear, permanently losing viscosity. 

Replacing your old differential fluid with fresh fluid will protect the internals of your differential, lessening the chance for harmful friction and contaminants to cause overheating and wear. 

Symptoms of Bad Differential Fluid

• Chattering or vibrations felt in vehicle
• Smell of burning oil
• Grinding, whining, or whirring sounds
• Uneven and rapid tire wear

How Often Should I Change My Differential Fluid?

Each vehicle and differential setup is different, meaning the exact lifespan of your differential fluid can vary considerably based on both the type of vehicle and the way in which you drive it. 

Those who often use their vehicles for towing will require differential services sooner, as the increased strain put on the axles will translate to the internals of the differential, increasing stress and friction. 

Differential fluid should also always be changed anytime the vehicle is driven into water, specifically deep enough for the differential case to be submerged. Water can leak into your differential, mixing with the fluid and creating a sludge that gums up the internals.

Fortunately, differential fluid lasts much longer than some of the other fluids in your vehicle, like coolant or engine oil. In general, we recommend differential fluid changes around every 30K-60K miles. Of course, you should have your differential looked at as soon as possible if you encounter any of the listed symptoms above. For vehicles that tow often, specifically in hot weather, you may be looking at more like every 30K miles for replacement. 

Differential Services in Summerlin

If you’re encountering unusual sounds or feelings from your drivetrain, you may require a differential service. The expert technicians at Red Rock Repair in Summerlin, Las Vegas have the equipment and training to properly take care of your differential, ensuring smooth operation and preventing dangerous overheating in one of the most important components of your drivetrain. Give us a call at (702) 385-7887 to speak with our friendly and knowledgeable team on the next step for your vehicle!