Transmission Fluid Change vs. Flush | Sun Devil Auto

Should I Get a Transmission Flush or Fluid Change?

Your car’s transmission plays an important role as it delivers enough power to the wheels to drive at certain speeds. Most drivers know that transmission problems are synonymous with expensive repairs. However, you can attempt to circumvent transmission repairs by using your parking brake when parking, coming to a complete stop before shifting gears from reverse to drive, and most importantly, by performing simple maintenance. Just like your engine needs oil for lubrication, your transmission also relies on transmission fluid for cooling and lubrication. Transmission maintenance includes transmission fluid changes as well as flushes. What is the difference, and should you choose one over the other?

Why Maintain Your Transmission?

Transmission maintenance benefits your vehicle in three ways:

  1. Prevents Overheating – Over time, particles from within the transmission and metal shavings accumulate in the transmission fluid. As it moves, the transmission as well as the fluid, begins to heat up significantly causing particles to burn and overheat internal components, resulting in system failures.
  2. Improves Gear Operation – When the transmission begins to overheat, the transmission fluid turns into a thick, gooey sludge, clogging gears making shifting between speeds difficult.
  3. Improves Fuel Efficiency – When the transmission is functioning optimally, less strain is placed on other mechanical components within the vehicle. By reducing the amount of friction produced by moving and rotating parts, the amount of energy is increased and is then transferred to the wheels, improving fuel economy.

Transmission Fluid Change Versus Flush

Now that you understand the importance of transmission maintenance, you’ll need to decide which service is best for your vehicle. What’s the difference between a transmission flush versus a change, and how often should they be done?

Transmission Fluid Change

When a technician performs a transmission fluid change, the transmission pan is dropped and drained, and the filter is replaced, if applicable. The technician then refills the transmission. Not all fluid is able to be

Hand pouring transmission fluid

removed, however, leaving up to half in the torque converter and cooler lines. Still, while not all fluid is new, much of the old, dirty fluid is removed making it more effective than before. By not replacing transmission fluid, and in some cases where transmission fluid is badly contaminated, it can pose a real danger to your transmission by causing overheating and making it work harder than necessary. Ineffective transmission fluid greatly reduces the life span of your transmission and may lead to failure. A fluid change is recommended every 30,000 miles or every two years, whichever comes first.

Transmission Flush

The benefits of a flush are self-evident. All the old, dirty fluid is removed and replaced with fresh, high-quality fluid. As a result, your transmission should run cooler and receive maximum protection against wear to clutches, gears, and bearings. You’ll also notice smoother, more consistent shifting since the new fluid will provide more effective frictional properties. Performing a flush also helps to cleanse the transmission. Sludge and other contaminants can accumulate in the fluid due to extreme heat breaking down the fluid. These contaminants then circulate throughout the transmission before lodging in the filter. Before the filter can safely capture the contaminants, however, they run the risk of lodging in the narrow passages inside the valve body, leading to poor shift quality. Performing a flush also allows you to use a flush additive to help clean the transmission and more effectively remove accumulated sludge and other contaminants. Transmission flushes are recommended every 45,000 miles or 3 years in place of a drain and fill or to replace fluid changes altogether.

Many people will argue that a transmission flush is more effective than a drain and refill because old fluid remains in the transmission after the change, contaminating new fluid, thus, diminishing performance. With a flush, all old fluid is removed with a flush machine and then new fluid is added, allowing the transmission to perform at its best. However, the cost of a flush is significantly more than a simple drain and refill. In any case, choosing a fluid flush or a drain and refill is better than not performing any kind of maintenance on your transmission. With some vehicles, a fluid flush or change is irrelevant as they may have a sealed transmission. Refer to your owner’s manual to be sure.

Maintenance Versus Repair

It’s important to note that a transmission flush is not a repair. While transmission flushes can aid in preventing major transmission troubles down the road, it’s not a guarantee. Many transmissions fail after a transmission flush, not because of the flush, but because the transmission was already at the threshold of failure. A transmission flush is not intended to fix transmission problems, it is meant to help maintain the transmission.

Transmissions are a large part of the movement of your vehicle. Without a functioning transmission, you won’t be going far. To keep your transmission operating to the best of its ability, be sure to have maintenance performed on it regularly. Whether you choose a drain and fill or a complete fluid flush or your transmission needs repair, seek out the Transmission Experts at Sun Devil Auto. You’ll be confident knowing our technicians have the knowledge and expertise to perform maintenance and diagnose and repair transmissions properly. We guarantee our work in writing with a 2-year/24,000-mile Nationwide warranty and work as quickly as possible to get your vehicle back on the road. For your next transmission inspection, service, or repair, give Sun Devil Auto a call.