Transmission fluid is a crucial part of keeping the components in your vehicle’s transmission system cool, lubricated, and working great. The role of the transmission system is to make sure that the correct amount of power makes it to the wheels from the engine at any given speed. This is done via changing the gear ratio. Transmission fluid assists the transmission’s moving parts in applying the correct amount of friction.

When not appropriately replaced, transmission fluid loses its ability to function as a lubricant and coolant. Often transmission failures occur due to neglecting to change the transmission fluid. As it degrades, the transmission temperature will increase during use. The heat further degrades the fluid, which then leads to problems such as knocking or banging into gear, pump failure, clutch pack slipping, and eventually, to transmission failure.

As such, it is important to know when to change the transmission fluid, how to check the signs that it needs changing, and how to change it. While you can always take your vehicle into one of our Utah auto repair shops to get the transmission fluid changed, it is always good to know when and how it should be done.

When to Change Your Transmission Fluid and How To Do It

(Tim Samuel/Pexels)

How to Know When to Change Your Transmission Fluid

There are a lot of factors that affect transmission fluid degradation and longevity. Some of these factors include traffic, climate, and towing. These variables will also affect how often you should change your transmission fluid.

For instance, if you are a truck owner that does frequent towing, or if you do lots of city driving that includes constant stopping during heavy traffic, then you may need to look into changing your transmission fluid more often. However, the overall recommendation for changing transmission fluid is every 30,000-40,000 miles–or five years–which is based on usual, everyday driving. Make sure to check your vehicle’s manual as well for specific recommendations.

How to Check Your Transmission Fluid

Generally, transmission oil is checked while the engine is running. Make sure that your vehicle is on a level surface. Find the transmission fluid dipstick and take it out. Wipe it clean and then put it all the way in and then take it out. This will tell you how high the fluid is, as well as the color and smell. To check the quality of the oil you can dab the dipstick onto a piece of paper or another surface. Here are some signs to look for:

  • If the oil appears reddish or pinkish, it is in good condition.
  • The oil should not smell burnt.
  • If the fluid looks foamy, then the transmission fluid may be overfilled.
  • If the color is brown or black and has a burnt smell then you need to get the transmission fluid changed. You also may need to have the transmission checked over as well.
  • If there are metal shavings or grit present in the fluid, then it needs to be changed and the transmission inspected.
  • If the transmission fluid is low, then you may need to get the transmission inspected to find out where the fluid is going.

There are lots of types of transmission fluids, so take a look at the vehicle’s manual to find out which specific fluid your vehicle may require. There may be alternatives, but you should know what is best for your particular vehicle’s transmission. To determine how much oil you will need for a typical transmission fluid change, look for the “pan” capacity for your vehicle. Typically, this is anywhere from three to six quarts of transmission fluid.

How to Change Your Transmission Fluid

  1. Lift the vehicle using a jack or ramps.
  2. Find the transmission’s oil pan and set up a drip pan to catch the old transmission fluid.
  3. Drain the fluid by either using the drain bolt or loosening the bolts to get the transmission fluid dripping until it pours out into the pan. Be careful as the old fluid might be hot. Note that as the bolts loosen, the oil flows faster.
  4. Carefully inspect the transmission pan. Lots of pans will have a magnet on the side to gather any smaller particles from the fluid. Small pieces of metal are pretty normal, but if there are larger pieces then you should get that looked at. Degrease the pan and wipe clean.
  5. Replace the filter and pan gasket.
  6. Place the pan back in and tighten the bolts appropriately.
  7. With a funnel through the dipstick hole, fill the transmission with new fluid until you get to the last half quart in your last bottle.
  8. At this point, start the vehicle, shift it into drive, up to reverse, and back to park, spending about two seconds in each gear. Repeat.
  9. Remove the dipstick and check the transmission fluid level. If needed you can then add the last half quart of fluid. Once the fluid level is at an appropriate level, you will redo step 8 another time to make sure that the fluid is functioning.
  10. With the vehicle running, take a look underneath to make sure there are no leaks. Do a short test drive.

Routine checks of your transmission fluid will go a long way in saving money over time, and obtaining an assessment of the fluid is as simple as getting under the hood and removing the dipstick for a quick clean.