What Causes A Transmission To Overheat?

For most vehicles, overheating is the key reason for transmission failure. If you want your transmission and engine to work perfectly, you should know what causes a transmission to overheat.

The reason can be burned or low-quality transmission fluid, worn-out or slipped parts inside the transmission, insufficient transmission fluid, faulty lock-up system, hot weather, or bad driving.

Let’s get into the details and find out why your car’s transmission is overheating and how you can fix it.

Transmission Overheating: Causes and Possible Fixes 

In almost 90% of cases, the transmission overheats due to various transmission fluid issues. If the fluid is good and sufficient, it can be the faulty inner components such as clutches, solenoids, or bands. Here are the possible reasons and fixes why your car transmission might be overheating.

Issues with Transmission Fluid 

• Bad Transmission Fluid:

When the inner parts of your car transmission move, they create a huge amount of heat due to friction. The function of transmission fluid is to keep the parts lubricated so that there are less friction and even lesser heat is produced.

Besides, it transfers the produced heat to the engine, where the radiator dissipates the heat. So, if you’re using degraded or low-quality transmission fluid, your transmission will surely overheat more frequently. 

Also, in case the transmission fluid is too old, it also fails to lubricate the parts properly. 

How to Fix?

Well, the solution is simple here, get rid of the bad transmission oil and replace it with a high-quality one. Burnt or contaminated fluid has a weird smell and darker colors such as brown, dark red, or black. 

On the other hand, fresh fluid has a clean pinkish look. The smell and color are the keys to determining whether your transmission fluid is worn out.

As for old transmission fluid, it’s recommended to change the old fluid every 30,000 miles.

Insufficient Transmission Fluid 

While refilling the transmission fluid, you must maintain an optimal level for proper circulation. If there’s any leak in the system or the fill level is incorrect, the components won’t be lubricated properly, causing more and more heat production.

Due to poor circulation, the heat won’t be transferred to the radiator, and the transmission won’t cool down as it should. Hence, your vehicle will start displaying signs such as weird noises, slipping, and overheating. 

You can check out the owner’s manual to know the optimum fluid level. A transmission dipstick will tell you if your vehicle needs more transmission fluid. 

How to Fix?

Monitor the fluid level regularly and refill whenever necessary. However, if the fluid level decreases too fast, there might be a leak somewhere in the system. In this case, you need to visually inspect the transmission system to locate the leak.

To fix the leakage problem, you’ll need help from an expert. You either fix the leak or replace the damaged part to get your transmission working again.

Internal Components Might Cause Transmission Overheating 

• Damaged Solenoid 

A solenoid in your transmission system controls fluid circulation. When the solenoid is damaged or defective, the transmission fluid will either overflow or there will be insufficient fluid for proper lubrication.

In both cases, the transmission will overheat, causing the system to fail. A thorough inspection of the solenoid and underlying circuits will help you address the issue.

How to Fix? 

You need to replace the damaged solenoid to get the system working again. If there’s any problem with the circuit, replacing only the damaged parts will be enough. We recommend taking help from a technician for the replacements.

• Defective Clutches and Brakes 

The inner components of the transmission function together to keep the system running optimally. Defective or worn-out parts such as clutches, bands, or brakes cause transmission slipping. As a result, a huge amount of heat is produced, causing the system to overheat.

How to Fix 

Locate the damaged component and see if it’s worth repairing. Otherwise, get a new replacement to keep the heat checked.

• Malfunctioning Torque Converter 

A torque converter contains the transmission fluid and creates hydraulic pressure. The fluid won’t circulate properly if something goes wrong with this component. Hence, the transmission components will create more and more heat.

How to Fix?

You can take your vehicle to an expert to repair the torque converter. Also, consider adding an aluminum-made deep pan to hold more transmission fluid.

This will keep your transmission lubricated even when the torque converter is malfunctioning.

External Factors Can Also Cause Transmission Overheat 

• Heavy Towing 

If you’re used to loading your vehicle or towing heavy weights frequently, it will put more pressure on the transmission, causing it to run hot. 

How to Fix?

Keep the transmission fluid level checked, and don’t exceed your vehicle’s weight limit.

• High Temperatures 

Hot weather can contribute to overheating the transmission fluid and the system components. This will happen more often if your vehicle lacks a transmission cooler. 

How to Fix?

Adding an external cooling system will help your vehicle to cool down even in the hottest weather. Install a stacked plate cooler to take off the extra pressure from your radiator.

• Driving Conditions 

Thanks to stop-and-go traffic, you need to constantly shift the gears to slow down or accelerate the vehicle. This puts more pressure on your transmission, causing it to overheat due to the friction of its components.

How to Fix? 

If possible, avoid driving while you’re stuck in traffic. Also, try not to pull a hard brake and shift gears more frequently.

Final Words 

So, there you have it all. We have discussed what causes a transmission to overheat and how to fix these issues. If you have good knowledge of car parts, you can easily repair or replace the related components causing your car transmission to run hot.

However, we recommend going to a technician in any situation to ensure maximum safety. Also, you can avoid transmission overheating if you regularly check the transmission fluid level and change the old and burn-out fluid whenever needed.