What to Know About Transmission Fluids

While they may not be at the top of your routine maintenance list, transmission fluid and differential fluid are important lubricants that serve a role in any heavy-duty fleet vehicle. The recommended timeline for replacing these fluids varies by manufacturer, application, and environment. For mile after mile, both of these fluids will deteriorate.

Signs Differential Fluid Needs to Be Replaced

There are some telltale signs that differential fluid needs to be replaced, including:

• The fluid is contaminated with other chemicals or metal particles
• Grinding noises when turning
• Presence of water and dirt in the differential fluid
• Humming while driving due to gears rubbing
• Increase in vibrations

Depending on your fleet, some vehicles may use a combined transmission and differential fluid. This is most common in front-wheel drive vehicles, while all-wheel drive and four-wheel drive vehicles have separate differential and transmission components.

Signs Transmission Fluid Needs to Be Replaced

A few specific situations are clear indications that it’s time to replace a vehicle’s transmission fluid, such as:

• Clogged transmission fluid filter, which prevents the normal flow of fluid and results in contaminated fluid
• Transmission seals have ruptured, resulting in lower transmission fluid levels
• Slipping gears, sharp or abrupt shifts, or clunking

How Often to Change Transmission Fluid or Differential Fluid? 

Every vehicle manufacturer provides specific instructions for replacing all your vehicle lubricants, including both transmission fluid and differential fluid. Always check with the owner’s manual or work directly with the manufacturer for their recommendation. Many mechanics recommend changing this fluid between 30,000 and 60,000 miles.

Fleet Vehicle Maintenance

Regular servicing is the key to getting long, reliable life out of your fleet. Encourage drivers to keep weekly notes on how their vehicles are performing, paying close attention to any of the transmission and differential warning signs noted above, so small issues are caught before they become big ones. Pair that vigilance with only the highest quality lubricants, and your fleet will log more miles, perform better on every job, and avoid the costly repairs and downtime that come with unexpected breakdowns.

Download: 8 Tips for Truck Maintenance

Maintain Your Fleet with Tilley Distribution

Having a reliable, quality lubricant supplier is an important part of ensuring your vehicles are running at peak performance for the long road ahead. We offer businesses the best lubricants and dynamic sourcing to make sure we deliver what you need, when you need it. Whether your order is 6,000 gallons or a couple of quarts, you can rely on our commitment to excellent service.

Talk to a Tilley team member today.