Three Possible Reasons Your Car's Transmission Is Overheating

27 October 2022
 Categories: , Blog


If your car's transmission is overheating, you must get it into an auto transmission repair shop for proper diagnostics and repair. Other than adding fluid, transmission problems always require a skilled professional.

An overheating automotive transmission is always a serious situation and is typically caused by one following three issues.

Transmission Fluid Problems 

The first place to investigate when a transmission is overheating is the fluid level and the quality of the fluid contained within the system.

Low transmission fluid can be rectified by adding new fluid into the reservoir. However, missing transmission fluid often signals a small leak somewhere that you must find and have repaired. If a small leak isn't fixed, it will become a bigger problem.

If the transmission fluid looks black, smells burned, or you can see metal filings in it, this is a sure sign you're transmission is damaged. When you see dark or burned transmission fluid when a transmission's gears are wearing it, it needs to be rebuilt. 

Clogged or Damaged Transmission Fluid Cooling Lines

As their name implies, transmission fluid cooling lines pull hot transmission fluid into the radiator, which is cooled off and then transported back to the transmission.

When a transmission cooling line is clogged, the transmission fluid cannot be cooled by the radiator, and this will cause your car's transmission to overheat.

The solution for a clogged coolant line is to flush out the transmission fluid system to remove the clog.

Transmission cooling lines are rubber hoses with metal fittings crimped on both ends. Since the cooling lines are under pressure, they tend to fail where the metal fittings are crimped onto the rubber hose.

When the crimp on the metal piece fails, the transmission cooling line will leak. Once too much fluid has leaked out, then the transmission will overheat.

The solution for a damaged transmission cooling line is to have it replaced at your local auto transmission repair shop.

Excessive Load on the Transmission

Finally, suppose your vehicle's transmission is only overheating when it is put under an excessive load from towing or traveling during scorching weather. In that case, it may need to have an aftermarket transmission cooler installed. 

An aftermarket transmission cooler acts as a heat exchanger. Inside the cooling unit is metal plates or fins. The transmission fluid is rerouted from the radiator through the transmission cooler, and any present heat is dissipated. The cooled fluid is then reintroduced into the transmission.

For more information, contact a company like Summit Transmission Inc.