Transmission distributes power

The transmission’s main function is to distribute the correct amount of engine power to the wheels by changing gears up and down according to your driving speed.

While today’s automobile manufacturers use five- and six-speed manual transmissions less frequently, the number of gears in automatic transmissions has jumped from four to as many as ten! Some gearboxes are controlled with paddle shifters on the steering column to recreate the experience of driving a stick shift.

Signs of a faulty transmission

  • Red fluid leaking under your vehicle
  • Whining and clunking as gears shift
  • Gears slow to shift
  • Gears grinding
  • Noises when vehicle is in neutral

Transmissions are designed to last a long time, but they will eventually wear out and need repair.

Prolong the life of your transmission by having your transmission fluid replaced on schedule. More than a lubricant, this fluid contains detergents and other additives to protect your transmission. Old fluid does not protect as well as new fluid.


If your transmission is not shifting as smoothly as it should, or if you suspect a transmission leak, have your NAPA AUTOPRO technician perform a routine maintenance and repair any leaks right away. This could prevent a several thousand-dollar repair!

In fact, your NAPA AUTOPRO centre will check your transmission fluid level with a full-service oil change. All automotive manufacturers make recommendations about which kind of transmission fluid to use and how often to change it. Your certified NAPA AUTOPRO technician can check your transmission fluid and replace it with the correct product (regular or synthetic, viscosity, etc.), if required.

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