Ask The Mechanic: How long does a car transmission last?

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One of the more complex parts of your car is the transmission. As simple as shifting the lever into gear seems, behind the scenes, complex mechanics and software do the work for you. A transmission sends the power produced by your engine to the wheels and enables you to drive at any speed. This is important work. Should the transmission stop or break down, your vehicle will not operate. With that complexity, how long does a transmission last?


How long does a transmission last in a car?

The average mileage lifetime on an adequately maintained transmission driven in normal conditions is more than 120,000 kms. Your mileage may vary considerably depending on the car’s type of transmission. Transmission manufacturer, make and model, driving conditions, maintenance levels and wear and tear all impact mileage. An automatic transmission can last 120,000 kms before needing additional care. Care and maintenance of the car are critical for the life of associated mechanical parts, including the transmission. Let’s look at some of the essential things that affect the life of a transmission.


Transmission fluid maintenance

Similar to engine oil, transmission fluid serves as a coolant for moving parts. Transmission fluid lubricates the bearings and metal parts inside a car’s manual gearbox, keeping them from grinding as they move. Automatic transmission fluid also serves as a hydraulic fluid to make internal components function as designed. The transmission fluid helps with gear lubrication, brake band friction and valve operation. If degraded fluid is not replaced, it will fail to perform these essential functions, and the transmission itself may fail soon, too.


Engine cooling system

Automatic transmissions operate best at or below 200ºF. For every 20º above the limit, you risk cutting the transmission’s expected lifespan by a factor of two. For example, suppose your transmission overheats to 300º. In that case, the heat will reduce the transmission’s lifespan to one-thirty-second of what is considered normal. Even with the temperature going up 40º, the transmission fluid can turn to varnish and won’t properly lubricate the transmission gearing. Overheating can be caused by pulling a load that’s too heavy, low transmission fluid or an overheated engine. The transmission fluid is cooled by coolant located on or near the car’s radiator. If radiator fluid isn’t cooling properly, the heat will also affect the cooling of the transmission fluid and vice versa.



Even the most powerful trucks have limits to the weight they can pull. Hauling or towing weight more than your vehicle was designed for whether you drive a sedan, or an SUV will bring consequences, including the strain on the transmission. Manual and automatic transmission clutches will cease to function and further wear out other components.


Fluid level

When changing your oil, check the radiator coolant, brake fluid and transmission fluid levels. Letting the transmission run out of fluid or operating it with a low fluid level is a guaranteed way to have a transmission break down. The fluid cools and lubricates the transmission’s internal components. When the fluid level gets low or runs out, the internal parts grind and overheat, leading to failure.


Nelson Xavier Ssenyange

Team Leader

Germax Auto Spares & Garage

Lukade Road, Naalya





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