5 Causes of Automatic Transmission Fluid Leaks
Automatic transmissions contain many moving components and parts. Like parts in an engine, the moving parts in a transmission also generate a lot of heat when they rub against each other.
This means that transmission parts also need to be lubricated in a similar way to an engine; the only difference is that gearboxes use gear oil instead of oil as a lubricant.
Having the right amount of transmission fluid inside your transmission reduces friction between components, ensuring your transmission stays cooler and functions as intended. What Causes a Gear Oil Leak?
Typically, you can wait until you’ve driven 60,000 to 100,000 miles before you need to change your automatic transmission fluid. However, if a leak develops anywhere in the transmission system before your regular oil change interval, this oil can be lost.
The most obvious sign of a transmission leak is if you notice a small puddle of reddish fluid under your car where the transmission case is. This red fluid is usually associated with transmission fluid, but old or burnt oil is more likely to be brown.
If you see transmission fluid under your car, you should take it seriously and have the leak repaired immediately. To help you pinpoint the exact location of the leak, here are the most common places where automatic transmission fluid leaks:
1) Faulty Transmission Pan Gasket
All vehicles with automatic transmissions are equipped with a transmission pan that stores transmission fluid. The mechanical seal between the pan and the transmission is called the transmission pan gasket.
This component prevents transmission oil from leaking from the pan into the transmission. If the seal is damaged or torn, transmission fluid will leak. If you don’t replace this seal, what starts as a small crack can get much worse.
2) Torque Pump Failure
The torque pump ensures that the transmission oil circulates throughout the transmission system. If the pump breaks, the oil will no longer circulate or you will develop a leak. Either way, you have a bigger problem that needs to be fixed immediately.
3) Transmission Oil Pan Damage
In most cases, the transmission oil pan will last the entire life of the vehicle. However, because the oil pan is attached to the transmission via fasteners and probably has at least one drain plug, if any of these parts become loose or damaged, it can easily develop a leak.
In fact, if you get into an accident or accidentally drive over a large rock that the transmission pan can’t get through, the oil pan itself can be damaged. You could end up with a dent or crack in your tub without even realizing it. If you determine that the transmission pan is the source of the leak, replacement is usually the best option.
4) Broken Gearbox Seal
The transmission seal in an automatic transmission maintains oil pressure in the lines. The only problem is that these seals are constantly exposed to heat while the transmission is in operation.
The seals will eventually wear down and crack when exposed to heat over time. The seals will leak transmission fluid. Any seal can lose this fluid: shift housing seal, plug seal, tail housing seal, output shaft seal, etc.
5) Broken Fluid Line
Transmission fluid lines are made from either aluminum or steel, so they are designed to last. However, if the lines are damaged by excessive heat, they will eventually crack and leak transmission fluid — no aluminum or steel is strong enough to prevent this.