Shop Talk

Q: Greg, when should I change the transmission fluid in my Honda Accord? I hear something different from everyone I ask. — Doug P., Holiday, Fla.

A: Doug, you don’t say whether you have an automatic or manual transmission, and they are very different in how they break down the fluid. Remember that just like the oil in your car’s engine, transmission fluid degrades or contaminates from heat, dirt, dust and debris.

Manual transmissions have less heat buildup than automatics, but more contamination occurs as tiny metal particles enter the oil every time the synchronizer is used and gears are changed. As the transmission fluid ages, oiling abilities break down as those tiny metal contaminants build up, leaving your vehicle’s transmission vulnerable to breakdowns.

In an automatic transmission, heat is the big culprit, and the fluid can actually break down because of the heat after going past the fluid-change mileage or time period. However, just as in a manual, tiny particles also contaminate the fluid, making it twice as bad to miss changing the fluid in an automatic-equipped car.

A complete transmission flush that replaces all the fluid in the transmission will assure you many miles of protection and reliability. Automatics will also need a new filter and gasket.

After a transmission flush, you’ll notice the smoother shifting and better performance overall. Don’t hesitate to get it done, and follow the owner’s manual for change dates and mileage schedule. The rule of thumb is 30,000 to 50,000 miles for manual transmissions, and 30,000 miles and up for automatics. (Some new automatics have lifetime fluids.)

Your dealer or independent garage can easily handle the chore. Expect to pay $45 to $75 for a normal automatic transmission.