manual gearshift

Transmissions and How They Work

Many people only think about their car’s transmission when there’s a problem, but proper maintenance and care is essential if you want your vehicle to have a long life. Let’s take a closer look at the transmission and how it works. From there, we’ll be able to determine the best way to prolong its durability and reliability so you don’t end up stranded on the side of the road.

What is a Car Transmission?

The transmission’s main job is to allow your engine to operate at a variety of speeds while providing the proper output. Without your transmission, you would only be able to utilize one gear ratio.

So, let’s say you only have the equivalent of third gear. This would make it very difficult to accelerate when you first pull out. Then, at higher speeds, your engine would scream. This won’t get you anywhere quickly and puts a lot of wear on the engine.

With the transmission, your engine makes better use of its torque. The transmission dictates the speeds your engine operates at.

manual transmission

How Does a Transmission Work?

There are two basic types of transmissions: the manual and automatic. Either one acts as the mediator between your engine and wheels. It converts power from the engine to the axles which rotate your wheels.

Your engine operates at high rotational speeds. On the flip side, your wheels rotate much slower. Without the transmission, you can’t control the speeds between the two. That’s why you need gear ratios.

Your transmission uses toothed gears which interact with one another for torque production. So, if you have a 20-tooth input gear working with a 10-tooth output gear, your output gear needs to rotate twice to make a full rotation of the input gear.

The gear ratio is calculated when you take the number of output gear teeth and divide it by the input gear number. So, in our example the gear ratio is 1:2 but often gets simplified to 0.5:1. This tells you how many times your output gear needs to rotate for one full rotation of the input gear.

The transmission has many gears of varying sizes. This allows for multiple gear ratio combinations. On top of that, you also have neutral, park and reverse. When you are in neutral, your engine completely disconnects from your drive wheels. When utilizing reverse, your wheels rotate the opposite way. Finally, in park, your car uses a latching mechanism which locks your wheels to prevent them from turning at all.

In a manual transmission, the driver is responsible for switching the gears. The automatic does it on its own with the help of fluid pressure. The fluid tells the clutches and bands when to change gears. This transmission uses a planetary gearset which consists of one sun gear surrounded by small planet gears enclosed in the ring gear.

Differences Between an Automatic and Manual Transmission

Anyone who has driven an automatic and manual transmission knows there are distinct differences between the two. The first thing you’ll notice is that the automatic car doesn’t have a clutch pedal. There’s also no gear shift; all you need to do is put the car in drive and get going.

Automatic gearshift in car

Overall they do the same thing, just differently. Let’s take a look at the advantages and disadvantages of each.

Advantages of Automatic Transmissions

  • The driver doesn’t need to worry about shifting gears. They stay focused on the road.
  • It’s easier when in rush hour traffic.
  • You can multitask while driving (even though we don’t recommend it).
  • Newer automatics shift faster than manual options.

Disadvantages of Automatic Transmissions

  • Aren’t good for starting on a hill.
  • Get worse gas mileage.
  • Doesn’t offer as much control.
  • More expensive to repair because of technology.
  • More expensive to purchase a car with one.

manual gearshift

Advantages of Manual Transmissions

  • Get better gas mileage (most of the time).
  • Allows more control over the way you drive your car.
  • Less expensive for repair.
  • Cheaper option in cars.

Disadvantages of Manual Transmissions

  • Requires additional learning.
  • Harder to find.
  • Difficult to get parts for.
  • Less convenient

What Does it Cost to Repair a Transmission?

One of the most expensive jobs a mechanic offers is transmission replacement. The average cost ranges from $1,800 to $3,400. A big chunk of this cost comes down to the transmission itself. For example:

  • Salvage/used transmissions cost $800 to $1,500
  • Rebuilt transmissions cost $1,100 to $2,800
  • Remanufactured transmissions cost $1,300 to $3,400

Then, there’s the labor involved in removing the old transmission and installing a new one. You are looking at four to ten billable hours which is going to run $500 to $1,200 depending on the shop’s rates.

used transmission

Basic transmission jobs are going to cost significantly less at just $300 to $1,400. For example, if you need your manual transmission clutch replaced, you’ll only pay between $800 and $1,500.

Many factors affect your repair cost. They include:

  • Make of your vehicle (domestic cars cost less than imports)
  • Damage extent
  • Older newer (newer cars tend to have easier to find parts)
  • Manual Automatic (manual transmissions cost less to repair or replace)
  • Shop prices
  • Your location

Why Does the Transmission Break?

The top three reasons that an automatic transmission fails are because of leaking transmission fluid, low fluid and a clogged fluid filter. On the other hand, the most common issues with an automatic transmission include a slipping clutch, difficulty getting into gear and having a clutch that sticks. Thankfully, most transmission issues, manual or automatic, are easily preventable.

How to Maintain and Service Your Transmission

The best way to prevent repairs to your transmission is to properly maintain the system. You need to follow these ten steps to maintain your automatic transmission:

  1. Check your fluid often. If it’s low, add more. If it doesn’t look new, it might be time to change it.
  2. Make sure you use the right type of fluid according to your manual.
  3. Maintain your cooling system. This reduces the workload on the transmission.
  4. Have your transmission flushed as per your owner’s
  5. Don’t change gears while you’re in motion.
  6. Let the car warm up as you drive.
  7. Change your transmission filter as per the owner’s manual.
  8. Don’t tow more than you need to.
  9. Have someone inspect your transmission each year.
  10. Don’t drive on a spare tire for too long.

mechanics under car

There are also some steps to follow to prevent wear on your manual transmission.

  1. Check and flush the fluids just as you would with an automatic transmission.
  2. Use your clutch carefully.
  3. Avoid using the engine to brake.
  4. Schedule regular inspections with your local service center.

Keep in mind that anytime you haul heavy objects or tow, your transmission burns through more transmission fluid due to the extra heat. To protect your transmission during these times, make sure you equip your vehicle with a transmission cooler.

Final Thoughts

The transmission is an amazing piece of machinery that deserves your respect. Without it, you won’t go anywhere in your car. That’s why you need to service it and care for it properly. Maintenance costs far less than repair, so treat your transmission with the gentle touch it deserves.


Get a new clutch for your car right here.



About Nishal Singh

Car enthusiast since before I could drive.

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