TECH TIP

What should you do if you have a vehicle come in for its first ATF change at 75,000 miles?

In this case, you probably should not change the automatic transmission fluid (ATF). After 75,000 miles, the fluid would be oxidized and would be far thicker than new ATF. Accordingly, the transmission's clutch packs would be worn, having become accustomed to the thicker oil. In such a situation, the clutch packs may be engaging only due to the very thick ATF. If you drained the transmission and filled it with new, thinner ATF, the transmission might not shift or work properly.

Before you perform an automatic transmission fluid change for your customers, be sure to ask them about the maintenance history of their vehicles. If a vehicle has 60,000 or more miles on it and has never had its ATF changed, the transmission fluid should be left alone. If a customer does not know the exact maintenance history of his/her vehicle or when the last ATF change was done, you probably should not change the ATF. Also, look over the customer's vehicle if it appears to have been poorly maintained; changing the ATF may be a bad risk.