Transmission repairs on Mazda 6 vehicles can be expensive because of the cost of individual components and the labor associated with complicated installation. Common issues to look out for include transmission overheating, clutch problems, mechanical flywheel failure and torque-converter faults.
If the transmission system in your Mazda 6 is hot to the touch or its fluid heats past 200 degrees Fahrenheit, you may see the transmission circuit producing smoke. The solution is to install a transmission cooler, the size of which can vary and must be matched to the maximum allowable weight of cargo, including passengers and luggage, you carry on a regular basis. Transmission coolers work to reduce the temperature of the transmission circuit by increasing the airflow around the hot components. Install it as close to the transmission as possible, between the radiator and the air conditioning condenser.
Check the transmission fluid dipstick for low fluid levels. This condition can reduce the transmission's efficiency, performance and engine-cooling power. If there is insufficient fluid level for an extended period of time, the whole car will suffer as a result, and you could see the engine fail. Black, dirty and burnt fluid indicates the fluid needs to be changed. According to Samarins, you should change the fluid between 30,000 and 50,000 miles. Mazda recommends using M-V fluid in 2.3L automatics, T-IV in 3.0L automatics, and GL-4 or GL-5 in manuals.
Often an intermittent sound, rattling in low gears is a common problem and has been identified as a transmission-related issue. The steering wheel will shake between 25 and 37 miles per hour. Rattling has also been noticed in some Mazda 6 wagons at slower speeds. To fix this issue, you will need to examine the half-shafts that link the differential with the wheels and replace them if they are showing signs of wear and tear, excessive motion or loss of grease. You can also replace the transmission bearings.
Some Mazda 6 transmission systems cause jolting in the vehicle. This issue can begin as a small annoyance but will become increasingly frequent and severe. Jolting is due to a problem with the torque converter or the solenoid inside the valve body. Look for damaged components and replace them if necessary.
Shifting or Slipping
Sudden shifts, also called slips, in gears can be an issue while driving. The revolutions per minute (RPM) counter on the dashboard of the vehicle will change dramatically with the sudden change in component performance. Check and replace the transmission valve body as this problem is potentially dangerous: regular gear slippage can cause significant damage to the clutch and gear mechanism; and if the gears fail at high speed, accidents can occur. Some gearboxes can also lose their shifting ability on an intermittent basis or will fail entirely.
As the term implies, delayed engagement means that the gears hesitate before meshing. To test your Mazda 6 for this issue, shift the car into park and start the engine. Keep your foot on the brake then shift into reverse. If the transmission engages immediately, it works fine. If it does not, you have a sign that the transmission is faulty or, at the very least, in need of some attention. No jolting or jerking should occur. Try alternative gears using the same technique. According to Samarins, if the delay is 1 second or longer, there is an issue.