Why does my Car have a Transmission Fluid Leak?

Your car may have a transmission fluid leak for a variety of reasons, but before we talk about why you have a transmission fluid leak, it’s important to talk about how to identify one. You’ll notice a bad transmission fluid leak when parked when you see some funny color or funny smelling oil on the garage floor when you move your car. Transmission fluid is often red and has a distinctly unpleasant odor. This doesn’t guarantee a transmission leak, as many power steering systems also use transmission fluid as the working fluid. While you’ll likely notice when transmission fluid is leaking fast, if you’ve got a slow leak, you might be experiencing shifting problems or you might not have any other indication that something is wrong. Since these symptoms can be misleading, it’s important to actually check your transmission fluid level looking for signs of a leak.

On most cars, you can check your transmission fluid level using the dipstick much like checking your engine oil. The dipstick is often a different color or say “trans” on the handle and will be towards the middle or back of your engine bay. You have to check the fluid level when your car is warmed up, after a 20-30 minute drive, and with the engine idling in Park on level ground. If the level is low, the only cause could be a leak. It’s important to stop a leak quickly to keep your transmission fluid at the correct level to prevent damage to your transmission.

Causes of a Transmission Fluid Leak:

Not changing transmission fluid often enough
Impact or accident
Normal wear and tear

Not changing fluid often enough

Since there aren’t a lot of ways for the transmission fluid to leak out, there aren’t many causes of leaks. One of the main culprits is simply not hanging your transmission fluid often enough. Your vehicle’s owner’s manual will give you the recommended service intervals for changing your transmission fluid under normal and extreme driving conditions. If you’re wondering how often you should change your transmission fluid, most vehicle’s owner’s manuals can be found online easily! As you drive, your transmission fluid picks up tiny bits of metal as the components inside wear. If you don’t change your fluid often, these bits of metal add up and can start wearing down the seals and gaskets in your transmission prematurely.

Impact or accident

If one of your wheels or axles is hit during an accident it can cause a transmission fluid leak. Your transmission has between 1 and 3 outputs shafts that are either driveshafts or CV axles leading differentials or out to your wheels. If any of these shafts are pushed into or jarred hard enough they can damage the seals in your transmission causing leaks after the accident. If you suspect this to be the cause of your leak, it’s often best to replace the seals and check the transmission casing for cracks or damage.

Normal Wear and Tear

Normal wear and tear can cause transmission fluids leaks simply due to the operating environment of your transmission. For example, the output shafts all come in direct contact with the seals around them so the motion of the shaft will eventually wear down the seal and cause a leak. Also, the temperature swings and constant shifting of the transmission can cause movement between the seals and gaskets in your transmission eventually leading to leaks as well.

Often times, replacing the leaking gaskets or seals in your transmission can be extremely expensive due to the labor cost associated with the repair. A less expensive way to seal your current leak, or prevent future issues with your car leaking transmission fluid, is to add BlueDevil Transmission Sealer to your transmission. BlueDevil Transmission Sealer is not like other transmission sealers that fill your transmission with powders or a thick sludge, to clog up your leaks, and consequently other parts of your transmission. BlueDevil Transmission Sealer is safe to leave in your transmission fluid until your next fluid change and will not clog or harm your transmission in any way. BlueDevil Transmission Sealer will expand and soften the seals and gaskets in your transmission to restore them to their original condition sealing your leaks permanently.