Why Is Your Automatic Transmission Leaking?

You notice something pooling beneath your car, so you grab a clean towel and place it on the ground underneath your car’s engine block. A few hours later, you return to find reddish drops soaked into the towel and sigh. You probably have a leak in your transmission.

Leaks in your automatic transmission are serious even in their early stages, but they grow worse the longer they’re allowed to persist. Without the transmission fluid to protect the internal mechanisms and gears of your transmission, they’ll be exposed to high levels of friction and wear down. When that happens, what began as a simple job of locating and fixing a leak suddenly turns into a job to rebuild the automatic transmission.

But what causes such problems?

The Pan

One of the most common reasons for a leak in the automatic transmission comes down to the pan. The transmission and its pan are located beneath your vehicle, so rocks and debris get kicked up and smash into the pan all the time. While pans can certainly take quite a beating, if a large enough object hits it with enough speed, it can crack a hole in it. No matter how small the hole, transmission fluid will find its way out of it and onto the ground.

The Pan’s Gasket

Unlike a head gasket, a pan gasket is actually easy to replace and inexpensive as well. Catching it early is the key, however, as driving with low transmission fluid is extremely damaging to your vehicle. The gasket normally fails due to heat exposure.

The Drain Plug

The drain plug does exactly that: plugs the drain in your vehicle’s transmission. This is the primary mechanism for keeping transmission fluid inside, where it can cycle through the transmission and lubricate it. However, plugs can wear down over time, and eventually, they develop a little give. Or, if you’ve had your transmission recently serviced, perhaps the mechanic didn’t tighten the plug properly. Both of these are relatively simple fixes that will save a ton of money down the road.

The Seals

Another common reason for a transmission leak comes down to the seals. A vehicle’s automatic transmission has several seals, located in the pan, plug, speedometer input seal, and finally in the tail housing seal, that expand and contract, doing so between hot and cold temperatures. Unfortunately, these seals can eventually start to crack, causing a leak.

The Fluid Line

Made from either aluminum or steel, fluid lines have a somewhat limited lifespan. Despite being durable, many cars and trucks will need to have them replaced at some point, especially as they’re subjected to the same kinds of assaults as the pan. In time, they’ll eventually either crack or break off.

The Torque Converter

Lastly, the torque converter is what pushes the transmission fluid through the system, acting as a kind of pump. If the torque converter is to blame, it’s usually because its body has cracked. When that happens, the needle bearings will become damaged the longer you drive. Unfortunately, this part can’t be repaired and must be replaced. Usually, you’ll have to have this problem diagnosed by a mechanic who can check the pan’s bolts.

The Key Is to Properly Maintain Your Automatic Transmission

When it comes to car repairs, transmission problems can be some of the most expensive, which is why it’s so important to take care of your transmission.

To this end, you should remember to check the transmission fluid’s levels once in a while, but remember to check with your owner’s manual to see if your vehicle’s engine needs to be running as you do this. Also, don’t forget to make sure you have the correct fluid.

You should also make transmission flushes a regular part of your automobile’s maintenance. Typically, you’ll want to do this every 30,000 miles. You can have your mechanic check the cooling system at this time as well, and once a year, they should check over the entire transmission to ensure that it’s in good working order.

Any problems with the transmission should be dealt with as soon as possible to prevent even more costly repairs down the road.

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