All calls welcome. We're here to help you!

You can also send us an email.

3133 Saturn Road Garland, Texas 75041

Repairing and Restoring Classics Since 1986Click here to see the vehicles we work on
Wilson Auto Repair News Sign Up
You love looking at classic cars. We've got them for you! GET PHOTOS OF OUR EYE-OPENING CLASSIC RESTORATIONS DELIVERED MONTHLY TO YOUR INBOX: ·  See pictures of car & truck restorations in progress ·  Get classic car care tips and resources ·  Discover restoration tips for do-it-yourselfers
Wilson's Auto Restoration Blog

Are Transmission Flushes Necessary?

A lot of car owners ask whether a transmission flush is necessary. The quick answer is yes, they are important. Like any other component of a car, the transmission fluid deteriorates over time and thus, needs to be replaced. What car owners should focus on then is the frequency: how often should you do a transmission flush?

This article will help you learn more about what a transmission flush is, how often you should do it, and when not to do it.

What is a transmission flush?

A transmission flush is a more thorough method of cleaning the transmission. It is usually done with a machine strapped to the transmission cooler lines. In this process, the machine gently pumps out the old transmission fluid and replaces it with the new fluid. Sometimes, the mechanic uses a cleaning solvent to remove the buildup of dirt and debris in the transmission. This ensures that when the new fluid is introduced, the transmission will work properly.

To note, a transmission flush is not the only want to change the transmission fluid. The other method is a transmission fluid change. In this method, the old transmission fluid is drained out naturally. However, this process allows you to remove most but not all of the old fluid. Both processes are helpful and may help extend the lifespan of the transmission.

The question lies in frequency

As mentioned earlier, a lot of the debates surrounding transmission flush revolve around how often you should do it. Some mechanics recommend doing a flush every 30,000 miles while others argue that the car should reach 100,000 miles first before doing a transmission flush.

The best thing to do is to consult your car’s manual. Some cars need little maintenance, and thus, they may not need a transmission flush every so often. However, other factors can affect the deterioration of transmission fluid. This includes:

  • Climate
  • Trailer towing
  • Carrying heavy loads
  • Frequent stop-and-go city driving

These factors influence the transmission’s operating temperature. More heat places more strain on the transmission and the fluid, thus speeding up the deterioration process. Aside from the transmission fluid breaking down, you also need to deal with the deposits of grime and dirt that may have built up inside the transmission.

How do you know if you need a transmission flush?

Here are the things to look out for:

  • Strange or grinding sounds from the transmission
  • Problems in shifting gears
  • Sudden surge forward or fall backward
  • Delay in movement after putting into gear

Another thing that you can check is the color of the transmission fluid. If the color is bright, it means it is clean. If the transmission fluid is comparably darker, it may mean that it has become dirty. A slightly darker transmission fluid is not a basis of a flush, however. It is best to consult the manual first.

When you should NOT do a transmission flush

If you find that the transmission fluid is black, smells burnt, and has little specks on it, do not flush it. It may mean that the transmission itself is damaged but has not shut down yet. A transmission flush will not solve mechanical problems if the transmission itself is the problem. In these cases, it is best to replace or rebuild the transmission entirely.

Overall, it is best to do a transmission flush before the transmission fluid has become too dark. If your car carries heavy loads, it is recommended to drop by the auto repair shop more often. If not, it is best to stick by the guidelines written in the manufacturer’s manual.




Subscribe to the Wilson Auto Repair Newsletter

Comments are closed.