Frequently Asked Questions About car Transmissions


Transmissions are complex mechanical systems involving thousands of individual parts and various connections to other crucial engine components. They are also one of the most durable systems in modern vehicles, requiring only minimal regular maintenance and occasional repairs. In the event a transmission needs to be repaired, rebuilt, or replaced, car owners are usually surprised at how complicated the process can be.

That’s why we’ve gathered up the most common questions we hear about transmissions, which will hopefully broaden your understanding of the system and why repairs are anything but simple.

What does a transmission do?

Car engines operate at a high internal speed whether you are driving fast on the freeway or stopped at a light. Transmissions work as an energy middleman, regulating the engine power flowing to the wheels so you can drive at the speed you desire.

What is the difference between manual and automatic transmissions?

Manual transmissions work like a bicycle gearshift, but instead of a chain lifting away from the gears, the clutch in a manual transmission disconnects the system from the engine. After you move the stick shift into a new gear, the release of the clutch reconnects the transmission to the engine.

Automatic transmissions do not involve stick shifts or clutches because they change the gears for you with the help of a torque converter. When the car begins to struggle at a lower or higher speed, the transmission senses the change and shifts into the appropriate gears.

Do transmissions need regular maintenance?

Transmissions should be checked about every 30,000 to 60,000 miles to ensure everything is working properly. Regular maintenance service includes checking the level and condition of the transmission fluid, a road test to check for shifting problems, and a thorough lift inspection to spot any evidence of minor damage before it requires major repairs.

How often does the transmission fluid need to be replaced?

Some manufacturers recommend changing transmission fluid out as often as every 30,000 miles, while others recommend waiting until 100,000 miles. Your car’s owner manual will provide the recommended schedule for your vehicle. But if your vehicle regularly pulls heavy loads, drives in stop-and-go traffic on a daily basis, or accelerates hard frequently, you may want to check your fluid sooner than recommended.

What are the signs of transmission problems?

The most common sign of a transmission problem is a failure to move when the engine is engaged. Other common symptoms include:

  • Slipping gears

  • Delayed shifting response

  • Difficulty moving the stick shift

  • Gears that grind or jump during acceleration

  • Whining, rumbling, clunking, or chattering noises

  • A burnt smell coming from beneath the hood

  • Vehicle shaking while driving at any speed

  • Leaking transmission fluid

  • Check engine light activated

Why is transmission repair so expensive? 

Transmission repairs are complicated and time-consuming due to all the individual components involved. During a major transmission repair, each part is removed, cleaned, and inspected in case damaged parts need to be repaired or replaced. Next, the inspected parts are constructed back together into one of many subassemblies, which also must be adjusted and tested for proper operation before being assembled back into the transmission case. Once the transmission is completely assembled, it must be reinstalled and reconnected to other components of the engine and wheels, with expert technicians testing and adjusting during the entire process. 

What decreases the life of a transmission?

Transmissions can last for years without needing to be repaired, but bad driving habits can damage transmission components and increase your chances for a breakdown. Driving behaviors to avoid include:

  • Driving on a cold day before the engine has a chance to warm the transmission fluid to operating temperature (this usually takes around 30 seconds)

  • Rocking the car back & forth when stuck

  • Shifting into reverse before the vehicle has stopped completely

  • Racing, which can cause heavy damage to the drivetrain

How does the transmission affect other vehicle components?

Some car parts, such as the brakes, have a limited ability to affect other parts of the car when they’re damaged. But damaged transmission components can severely affect the functioning of other car parts, including:

  • The engine: Without a properly working transmission, the energy produced by the engine isn’t used effectively & engine performance will suffer.

  • The driving axle: The driving axle needs the proper amount of power & force to propel the car forward, which isn’t possible with a damaged transmission. 

  • The wheels: The wheels also receive power through the transmission to keep the car driving smoothly & at the intended speed.

Always enlist trained transmission experts to inspect and repair your transmission

One of the biggest mistakes car owners make is taking their car to general auto repair shops that don’t specialize in transmissions when transmission service or repair is needed. At Ruffner Transmission in San Diego, we have over 20 years of experience in transmission repairs on vehicles with manual, automatic, and four wheel drive transmission, as well as continuously variable transmission (CVT) vehicles. Our technicians have the expertise to diagnose your vehicle’s problem quickly and fix it right the first time.