Signs of transmission failure and ways to prevent it

Learn the signs and symptoms of transmission failure and how to keep yours running optimally.

Pictured: An original manual transmission in a 1996 Toyota Corolla.

Transmissions “transmit” power created by the engine to the wheels to move the vehicle forward. Without the transmission, your car would start but it wouldn’t drive. Some transmissions can last the life of a vehicle, but they are also capable of wearing out. Keep reading to learn the signs and symptoms of transmission failure and how to prevent it.

Luckily there may be some potential DIY fixes before a bad or failing transmission blows out completely, leading to a costly repair or new vehicle entirely.

Are transmission repairs expensive?

Sometimes a bad transmission can be fixed with a filter and fluid change, which on many vehicles is a DIY job that you can do at home with the right tools. If the fluid needs to be changed and you want to fix it yourself, check out our video library to see if we have a how-to video for your year, make, and model.

Other times a bad transmission may cost more to fix. Transmission repairs are often expensive. Because it is a complex part, repairs usually require mechanics who specialize in them. Lots of parts make up a transmission, and fixing a single part is usually not worth the time and trouble for the price—especially in older vehicles. Sometimes it’s more practical to just buy a new vehicle.

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Signs of a failing transmission

Leaking fluid

In some cases, leaking fluid means there’s a bad seal or cracked transmission oil pan, but transmission fluid is important and necessary for properly functioning gears and parts. Without fluid, the gears won’t switch as intended and may overheat, which can cause transmission damage.

Check engine/warning light

Your owner’s manual will explain how your vehicle will indicate transmission failure before it becomes a problem. In newer vehicles, the check engine light will illuminate. Computer fault codes can make diagnosing the problem easier.

Grinding, whining, or buzzing sounds

Feeling or hearing these sounds may mean internal parts have worn or are wearing. In vehicles with manual transmissions, the noise is quick and could mean the clutch or transmission synchronizers are wearing. Sometimes changing the fluid will fix these sounds, but they are better diagnosed by a professional.

Rough shifts

Transmissions were designed to shift smoothly. A continuous jolting nearly every time the car shifts means there may be something wrong internally and can be inspected by a professional mechanic.

Delayed shifting/slipping

Similar to rough shifting, if the transmission takes some time to shift into the right gear and the engine revs up faster than the transmission shifts gears, the issue may be the transmission.

Dirty fluid

Dirty or old fluid can keep the transmission from working efficiently and make it more difficult to keep its internal parts cool. Clean transmission fluid is pink and clear. On many vehicles, you can inspect it with a transmission oil dipstick.

Ways to prevent a failing transmission

Check and change the fluid regularly

Check your owner’s manual for best practices on checking the transmission fluid. Inspect the fluid level and color periodically as recommended or every few months, and change the oil and filter as recommended or every 30k-60k miles. Check out our how-to videos to learn what steps are involved and how to do it yourself.

Be attentive to acceleration and shifting

To extend the life, it helps to stay aware of how you’re driving. Accelerate gently to allow the transmission to shift smoothly. If your vehicle has an automatic transmission, don’t shift from drive to reverse or reverse to drive while the vehicle is moving.

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2 thoughts to “Signs of transmission failure and ways to prevent it”

    1. It could be a lot of things, but a weak ignition coil is where I would start. Ignition systems typically malfunction under load, so the fact that it happens in overdrive would make sense.


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