What Can Make a Transmission Go Bad? Reasons, Diagnosis, Preventions!

Transmissions are one of the most important components of any vehicle, and when they go bad, it can be a major inconvenience and a costly repair. But have you ever wondered what can cause a transmission to fail? 

So, today I will answer what can make a transmission go bad?

The common reasons that can make a transmission go bad are burnt or contaminated fluid, overheating, wear and tear, dirty oil chamber, etc. Other major reasons include damaged transmission bands, faulty torque converter, towing/hauling heavy loads, braking/parking on an incline, etc.

Now, let’s discuss the causes and symptoms of a failed transmission in detail.

What Can Make A Transmission Go Bad? Common Reasons

Transmission can go wrong for low transmission fluid, oil leakage, using the wrong fluid types, and worn-out or damaged gears. Other significant reasons include overheating, broken/damaged transmission bands, faulty torque converter, clogged transmission oil filter, faulty clutch, etc. The causes may vary depending on the transmission type.

There are primarily two types of transmissions: Automatic Transmission and Manual Transmission. Manual and automatic transmissions can be divided into the following subcategories. All of them have their advantages and disadvantages.

  1. iMT (Intelligent Manual Transmission)
  2. AMT (Automated Manual Transmission)
  3. CVT (Continuously Variable Transmission)
  4. DCT/DSG (Dual Clutch Transmission/Direct-shift Gearbox )
  5. Manual Transmission

Now, let’s discuss the common reasons first that can make a transmission go bad. I’ll move to the dedicated reasons for the automatic and manual transmission later on.

Reason 1: Contaminated/Burnt Transmission Fluid

Contaminated transmission fluid can cause potential damage to the transmission system. Overheating and contamination can decrease the viscosity of transmission oil, making it less lubricating and effective. 

Additionally, contaminated oil can clog the fuel filter, reducing the oil flow. Thus, make sure you check the transmission oil regularly and change it if necessary. Furthermore, the fuel may get burnt due to overheating and needs to be replaced.

Maintenance: To check your transmission fluid’s condition, place the dipstick on a white surface, such as a paper towel. The color of the fluid indicates its condition and, to some extent, the transmission’s condition. A reddish-pink color indicates a healthy fluid, while brownish-red signals the need for replacement. 

Additionally, dark brown or black color transmission fluid is a cause for concern as it may indicate internal transmission damage. Furthermore, dark fluid with metal shavings and a burning odor indicates the transmission’s internal components are damaged.

Image Source: Pinterest

Reason 2: System Overheating

Overheating is the most common cause of all types of transmission systems. The internals of the transmission can overheat for several reasons. These are:

  • Fluid level too low: Lack of transmission fluid is the main reason behind an overheating transmission system. When the transmission system lacks an adequate amount of transmission fluid, it causes the parts to produce more friction. As a result, it overheats the system damaging the components.
  • Clogged fuel filter: The fuel filter of the transmission is responsible for filtering the fuel from all sorts of contamination. Over time, the fuel filter can be clogged and dirty, leading to low or no flow of lubricant in the system. This produces overheating and system malfunction.
  • Failed cooling system: The transmission cooling system is located behind the radiator. It helps to dissipate the heat generated by the transmission system. Hence, a malfunctioned cooling system can lead to overheating. 

Prevention:  To prevent transmission overheating, follow the below maintenance guide:

  • Use the correct fluid type: Transmission fluid (types and required amount) varies depending on the vehicle’s requirement. You can find the recommended fluid type in the vehicle’s user manual. The transmission will fail if you don’t use the correct fuel type, and its longevity will also be shortened.
  • Ensure sufficient transmission fluid: The transmission system needs an adequate amount of transmission fluid for optimal performance. Check the fluid level and condition periodically and make necessary changes.
  • Change old transmission fluid: Make sure you perform routine maintenance and change the transmission fluid at the appropriate intervals. The changing interval of your transmission fluid depends on the type of transmission you have. 

For manual transmissions, it’s recommended to change the fluid every 30,000 to 60,000 miles, according to most manufacturers. For automatic transmissions, the changing interval can be extended to 60,000 to 100,000 miles.

  • Use an external cooler: If you use your vehicle to carry heavy loads like automotive parts, wood, or other heavy materials, it puts more stress on your transmission system. An external transmission cooler is a smart choice for your vehicle.

External transmission coolers can help reduce friction in an automatic transmission by reducing the temperature of the transmission fluid. When the transmission fluid is too hot, it can break down and become less effective at lubricating the transmission’s moving parts. 

This can increase friction and cause excessive wear and tear on the transmission, potentially leading to costly repairs or even transmission failure. External coolers can reduce the temperature of transmission fluids, thereby enhancing their lubricating properties and potentially extending their lifetime.

  • Add a deeper transmission pan: The transmission pan holds the transmission fluid required to flow through the system. A deeper pan will allow the system to hold more transmission fluid, dissipate the heat and quickly remove it from the transmission. Use a deep aluminum pan, which dissipates heat faster than steel.

There are downsides to using a deeper pan as well, such as the fluid taking longer to cool down. Furthermore, deeper pans are more expensive than regular ones, and they may require additional modifications to fit in some cars. Finally, they’re more prone to get hit from external sources, increasing the risk of pan leakage.

Reason 2: Mechanical Wearing

Due to excess friction, the internal moving components can wear over time. The transmission system consists of lots of moving gears. If any of the gears get damaged or the teeth get worn out, it can cause severe malfunctions and costly repairs. Replace the worn-out parts to reduce internal friction, as well as ensure regular maintenance.

Symptoms: Here some symptoms you may face:

  1. Unusual sounds when the vehicle is in neutral.
  2. Gears slipping or not engaging properly.
  3. Clutch sticking or not releasing fully.
  4. Fluid leaks from the vehicle.
  5. Illumination of the check engine light.
  6. Grinding or shaking sensations while driving..

Prevention: To minimize wear and tear on your transmission, follow these steps:

  1. Avoid overloading your vehicle, especially during hot weather or long trips.
  2. Regularly check your transmission fluid and get professional service as needed.
  3. Avoid excessive revving of the engine and rapid gear changes.

Reason 3: Improper Driving Style

Improper driving style can put the transmission system at risk. You should never shift between the gears without stacking the RPM properly. Now you might be wondering, what is RPM stacking. 

Every gear needs to reach a certain RPM count for optimal gear shifting and smooth driving, shifting earlier or over-revving will cause damage to the engine. 

Reason 4: Dirty Oil Chamber

A dirty oil chamber is another reason for transmission system failure. Every car has a pan-sized oil chamber that holds the transmission oil. The oil travels to the transmission system through pipes. If the oil chamber is dirty, it can contaminate the oil. 

Periodically clean the oil chamber to prevent oil contamination. You can watch this.How to do a Transmission Flush at Home for $12

Reason 5: Broken Oil Seal

Oil seals, also known as shaft seals, prevent the oil from leaking from the transmission system. It seals the gaps between the housing and shaft. Additionally, it keeps contaminants such as dust, dirt, and water out of the transmission system. If the seal is broken, it can cause the oil to leak, and external contaminants can enter the system.

Solution: Replace the oil seals/shaft seals to prevent further oil leaking and contamination. Consider watching this Oil Seal Removal and Installation


The common reasons for a transmission going bad are dirty/burnt/old transmission fluid, transmission system overheating, broken oil seal and mechanical wear. Other reasons include improper driving and a dirty oil chamber.

What Can Make A Transmission Go Bad? Automatic & Manual

Apart from the above reasons, there are other major reasons for transmission failure. Luckily, most of them are easily fixable. Here goes the list

Reason 1: Damaged Transmission Band 

Transmission bands are rubberized bands that are responsible for controlling the transmission gears. If the transmission band is damaged or worn out, it can cause the gear to slip or fail to engage properly. Similarly, if the bands are too tight, they can cause wear and tear on the gears, eventually causing them to break.

Solution: To fix a transmission band, have your vehicle inspected by a professional mechanic. The repair process will vary depending on the specific issue with the band. Certain bands may only need to be adjusted, while others may require replacement. 

Additionally, the problem may be related to another component of the transmission, such as the fluid, so it’s essential to get a thorough diagnosis. Hence, get the help of a mechanic to diagnose and identify the source of the issue thoroughly.

Reason 2: Faulty Torque Converter 

The torque converter is a critical component of an automatic transmission system. It is responsible for transferring power from the engine to the transmission and allows the vehicle to shift gears smoothly.

The torque converter uses hydraulic fluid to transfer power from the engine to the transmission. The fluid is pumped and pressurized by the torque converter, which allows it to operate effectively. If the torque converter malfunctions, it can cause a drop in fluid pressure, which can lead to gears slipping out of place or operating erratically.

Solution: Have your vehicle checked by a mechanic and perform a replacement. Here’s a video guide on the general understanding of the replacement process. How to Replace a Torque Converter for an Automatic Transmission

Reason 4: Defective Valve Body

The valve body is known as the control center of the transmission system. It’s responsible for carrying the transmission fluid to clutches and bands. A defective valve body can lead to fluid leakage and delay in shifting gears. 

Symptoms: Here are some major symptoms to determine if the transmission has a defective valve body.

  1. Difficulty downshifting to lower gear.
  2. Unexpected gear slipping.
  3. Automatic upshifting or downshifting.
  4. RPMs surge during upshifting.
  5. Loud banging noise when shifting gears.
  6. Delayed or hesitant shifting during acceleration or deceleration.
  7. Check engine light is on, and one of these P codes is detected: P2707, P0829, P0715, P0783, P0751.

Prevention: You need to replace the defective valve body to solve this issue. Here’s a video guide to give you an idea of the replacement procedure. Get your car to the nearest service center or hire a mechanic who will do the replacement for you.AUTOMATIC TRANSMISSION VALVE BODY REPLACEMENT REMOVAL ON A CAR

Reason 5: Braking & Parking On An Incline

Braking on an incline can potentially damage a transmission due to the increased strain it puts on the transmission. When you brake on an incline, the weight of the vehicle is shifted forward onto the front wheels. 

As a result, the transmission has to work harder to keep the vehicle in place. This can cause the transmission to overheat, wear down the clutch or bands, and lead to premature transmission failure over time. 

Similarly, frequent parking of your car on an incline makes the transmission go bad. The park position on a transmission works by inserting a metal arm, called a pawl, into a gear, which jams the transmission and keeps the car from moving. It is designed to hold the car on relatively flat surfaces.

If the car is parked on a very steep hill, the pawl or gear can be damaged. The difficulty of pulling the transmission lever out of the park position when the car is inclined indicates that it is being over-stressed. 

Reason 7: Launching the Vehicle

Launching the vehicle typically refers to what we did in the racing games in our childhood. Holding both the acceleration and brake pedal at the same time for a quick burst of acceleration. Incorrect or excessive launching can damage a vehicle’s clutch, transmission, and driveline components and the tires. Here is what you can watch.

Reason 8: Inching Forward

Inching forward your vehicle refers to the practice of lightly engaging the clutch and moving forward slowly without fully disengaging the clutch or pressing the accelerator. Inching forward can damage the transmission and shorten its lifespan.

It’s because inching forward can cause the clutch system to wear out more quickly, as the clutch is not fully engaged and is not receiving the proper lubrication. Additionally, it creates friction and heat on the clutch and pressure plates, ultimately damaging the transmission system.

Reason 9:  Towing Heavy Loads

Towing heavy loads can cause damage to transmission over time due to the added strain it puts on the transmission components. Transmissions generate excessive heat as they transfer power from the engine to the wheels. This can cause damage to the clutch, gears, bearings, and other components, leading to transmission failure. 

That’s why some automotive experts recommend automatic transmissions for safety purposes since they make shifting gears a simpler process, and some come with a tow/haul mode. However, manual transmissions may be better for towing off-road on uneven terrain. Automatic transmissions offer better control in tricky driving situations and are more efficient. 


The major reasons for an automatic or manual transmission going bad are  damaged transmission bands, faulty torque converter, and towing heavy loads. Other reasons include braking/parking on an incline, vehicle launching, and inching forward while driving.

Now let’s look at the potential symptoms of transmission system failure. Automatic and manual transmissions may show different and unique symptoms. Here goes the list.

What Are The Symptoms Of a Bad Transmission? (Automatic /Manual)

Now, let’s discuss the major symptoms of a bad transmission. Automatic and manual transmission have different symptoms as follows.  

Bad Automatic/Automated Manual & Manual Transmission Symptoms

Here are the possible automatic or automated manual transmission (AMT), and manual transmission failure symptoms:

Symptom 1: Check Engine Light On

Check engine light can come on for several reasons, including when the transmission system or any of the sensors malfunctions. So if the light is on, you should stop driving and get the car diagnosed by an expert as soon as possible.

Symptom 2: Transmission Won’t Engage

The first and the most common symptom of an automatic transmission failure is when the gear won’t engage. It can be caused by low transmission fluid, damaged or disconnected shifter cable, problems with the valve body, etc.

Symptom 3: Delayed/Hesitate Shifting

If the transmission system is damaged, you will feel a slight delay while shifting between gears, known as sluggish transmission. This can generally be caused by insufficient fuel pressure, a faulty fuel pressure pump, or a worn-out clutch. 

Symptom 4: Gear Slipping/High Engine Revs

When a transmission is unable to engage with the engine properly, it may slip, causing a loss of power and eventually resulting in a complete breakdown. Common causes of transmission slipping include computer control problems, lack of maintenance, and excess wear and tear.

Symptom 5: Weird Noises When Shifting

Transmission can sometimes cause grinding, buzzing, or clunking noises. The main reason for these weird sounds is inadequate transmission fluid. Friction between the gears can cause noise if the transmission’s mechanical components aren’t lubricated.

Symptom 6: Burning Smell

If something smells like burning, it primarily indicates that the transmission fluid needs service. It can also happen if you use the wrong transmission fluid. Additionally, it can happen if the transmission fluid overheats due to contamination or friction. 

Symptom 10: Engine Stalling

Engine stalling issue is common in the transmission that has a torque converter. The torque converter is responsible for managing the transmission fluid and keeping the engine running while at the stop. If there’s a problem with the torque converter in the transmission system, the clutch will fail to engage, causing the engine to stall.  


Common symptoms of a transmission going are check engine light on, transmission won’t engage, delayed/hesitated transmission, and gear slipping. Other reasons include weird noises, burning smells, and engine stalling.

Bad Manual Transmission Symptoms

Now, let’s check out the potential symptoms of manual transmission failure.

Symptom 1: Hard Shifting to Gears

If you find it harder to shift between the gears while driving, it primarily means loose linkage, broken or worn-out shift cable or bearings. Some other causes include:

  1. Insufficient amount of transmission oil.
  2. Using incorrect transmission oil type.
  3. Worn out internal parts like shafts, lever, etc.
  4. Synchronization issue due to bad motor mount.
  5. Misalignment in the transmission (After service).

Symptom 2: Transmission Stuck In Gear

Transmissions stuck in gear can indicate underlying problems that require attention. One of the first things to check for is low oil levels, as this can cause friction and heat to build up, which can cause the transmission to stall. 

Additionally, problems with linkage or shifter assembly, internal components, worn-out or broken drive gear teeth, a stuck shift rail, or a misaligned transmission can also cause the transmission to get stuck in gear.

Symptom 3: The Transmission Jumps Into Neutral

The main reason for the transmission jumping into neutral is worn or damaged gears. If the gears in the transmission are worn or damaged, they may not be able to engage and disengage the gears properly. This can cause the transmission to jump out of gear.

Worn-out gears also cause the input shaft to vibrate. Other reasons include misaligned or loose transmissions (possibly after a service/repair), misaligned clutch housing, a loose shift cover, or worn-out gear sprockets. 


Manual transmission symptoms include hard shifting, transmission stuck in gear, and the transmission jumping into neutral on its own. These symptoms indicate that your transmission is going bad and needs to be checked and fixed immediately.

Can a Transmission Go Bad From Sitting?

No, the transmission system can’t go bad solely from sitting in the car for a long time. However, the transmission oil and other components may degrade over time, compromising the performance and functionality of the transmission system. Here is how sitting in the car for a longer period of time can affect the transmission.

  • The oil can degrade over time: If your car is sitting for too long, it can negatively affect the critical fluids in your car. Transmission oil can degrade over time from sitting idle. Over time, moisture from the elements can cause corrosion in certain areas. 
  • Seals can dry out:  If the seals can dry out, fail, or weaken, the transmission fluid can leak from hoses and gaskets over time. As a result, the contaminant can enter the transmission system and pollute the oil, causing damage to the transmission.
  • Bad or weak battery: Sitting your car for a long time also negatively affects the battery. The automatic transmission system and sensors are electronically controlled in automatic transmissions. So a bad or weak battery will affect their performance.

Frequently Asked Questions

Can Transmission Go Bad Without Any Warning?

Yes, transmission can go bad without any prior warning or showing any symptoms, just like any other automobile parts. In some cases, the transmission may fail suddenly due to a catastrophic failure, while in other cases, the failure may occur gradually over time. That’s why regular maintenance is essential to ensure everything is working fine. 

Can you drive a car with transmission problems?

You can drive with transmission problems but you shouldn’t drive since there could be any unexpected circumstances that can put your life at risk. Also, force driving a car with bad transmission can lead to further internal damages and costly repairs. You should first diagnose the problem and get it fixed immediately before giving your car another drive.

Can transmission damage be repaired?

Yes, minor repairs like a defective solenoid, sealing leaks, replacing worn parts, etc can be repaired. These repairs are relatively simple and can be done quickly. However, major transmission repairs, such as disassembling the transmission and thoroughly inspecting all of its components, are more labor-intensive and can be quite costly.

The Bottom Line

That was everything about transmission and your query on what can make a transmission go bad. Hopefully, you’ve got all the reasons and potential symptoms to identify transmission issues. 

Never ignore the symptoms and get immediate assistance. Ignoring them can be fatal and can lead to expensive repairs. Ensure regular maintenance and routine checkups.

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William Baldwin

This Is William Baldwin, The Founder & Managing Editor of this website. Me and my team share automotive tips, tricks, and news

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Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at Autoglobes.com with a passion for the automotive industry.