The box that contains the gears is called a gearbox. The gearbox is one of the most important parts of the vehicle. It helps to increase or reduce the vehicle speed.
When the gearbox goes bad, it generates different symptoms. This article mainly explains the bad transmission symptoms, causes and how to fix it.
What is a Gearbox?
The gearbox is also known as a transmission. The main function of the gearbox or transmission is to vary speed and torque between a drive (such as an electric motor) and a load according to the requirements.
Most car engines have high operational rpm, so transmission allows the machinery to work effectively and also helps to slow or shut down the machinery.
Signs of a bad Gearbox
As the gearbox goes bad, it generates one of the below-given signs:
- Overheating
- Transmission Fluid Leak
- Check Engine Light
- Poor response from the gearbox
- Abnormal Noise
- Shaking or Grinding
- Burning Smell
- Car struggles to change gear
- Gear Slippage
- Dragging Clutch
- Vehicle Won’t Go into Gear
- Excess Noise When in Neutral
- Limp Mode
- Automatic Transmission Doesn’t Pull
- Jumping out of gear
1) Gearbox Overheating
An overheated gearbox is one of the major symptoms of a faulty gearbox. The transmission fluid is used in the vehicle transmission system. This fluid helps to decrease friction between the gears and prevents overheating. When the transmission fluid starts to leak, it may lead to some serious problems.
2) Transmission Fluid Leak
The transmission fluid leak indicates that your transmission system is damaged.
When the fluid starts to leak, you may notice bright red fluid pooling under your car. However, if your vehicle fluid burns due to friction in the transmission, it can turn black or brown. In this case, you may need to inspect and repair the gearbox.
Read More: Symptoms of Transmission Fluid Leak
3) Check Engine Light
The check engine light illumination is one of the clear symptoms of a bad transmission.
The check engine light tells you about the problem before it goes severe. Don’t try to ignore this warning. When your check engine light illuminates, immediately stop the vehicle and diagnose the reason for the problem.
In such conditions, Inspect the level of the transmission fluid and engine coolant or take your vehicle to a mechanic.
However, your vehicle’s check engine light can indicate different problems such as a faulty fuel injector, a bad spark plug, insufficient engine oil, or a coolant leak.
Read More: Causes of Check Engine Light Illumination
4) Poor response from the gearbox
The poor response or inefficient working of the gears is one of the common signs of a bad gearbox. In such a condition, you may face problems with gear change.
Signs of hesitation or total refusal to shift gears may also indicate a hydraulic, electrical, or mechanical problem with the transmission.
If the transmission is damaged, you may observe a clear difference between shifting gears and the actual increase in engine speed. The car can also accelerate more slowly than the desired speed.
5) Abnormal Noise
Abnormal noise is also a clear symptom of the bad gearbox. If your gearbox is making noises such as buzzing, howling, rattling, or humming that you have never heard before, there may be a problem with your gearbox.
The gearbox contains multiple moving parts. This unexpected noise may occur due to a damaged part.
Although the symptoms of gearbox bearing failure in a manual gearbox tend to be “clunk,” while automatic gearbox usually produces buzz or hum noise.
Remember that this type of noise may also generate due to damaged exhaust valves, driveshaft, or engine. In any case, you must drive your vehicle to the mechanic for inspection.
6) Shaking or Grinding
As the gearbox goes bad, your vehicle may start grinding, jerking, or shaking while driving.
When the automatic gearbox goes bad, it starts trembling, slipping, or hesitating when changing gears. However, when the manual gearboxes go bad, they are more likely to be ” grind. ” The gearbox mount or a bad engine may also cause shaking or jerking.
7) Burning Smell
If you observe a rubber-like burnt smell accompanied by fluid leakage, you may have an issue with your gearbox. Smoke can also be seen.
The burning smell indicates that your transmission is not getting sufficient fluid and moving parts are overheated that are producing a rubber-like burning smell.
8) Car struggles to change gear
If your vehicle struggles to change gears, it means that there is something wrong with the gearbox. However, this issue may also be occurred due to low transmission fluid, a solenoid failure, a sensor failure, or a clogged filter. In such conditions, you should drive your vehicle to a professional.
9) Gear Slippage
Gear slippage is one of the noticeable symptoms and warns that the manual or automatic transmission has failed and your vehicle requires professional attention.
10) Dragging Clutch
The dragging clutch occurs when the flywheel and clutch disc do not unlock as the clutch pedal is depressed.
A dragging clutch issue leads to gear clashing and unintended vehicle movement during gear changes. This problem is typically a result of mechanical malfunction or improper alignment of the clutch components.
Read More: Symptoms and Causes of Low Engine Oil
11) Vehicle Won’t Go into Gear
If you find yourself in a stationary car with a running engine that won’t move, it may point to issues with the gearbox. It’s also possible that your transmission is stuck in first gear.
There are numerous potential causes for your car’s inability to shift gears, such as using the wrong type of transmission fluid, defective sensors, malfunctioning clutch connections, mechanical breakdown, clogged filters, misaligned shift cable, failed solenoids, or a faulty computer system.
12) Excess Noise When in Neutral
Unusual noise while your car is in neutral mode may also indicate an issue with the transmission. If your car produces an excessive banging sound while in neutral, an engine inspection is necessary. However, your vehicle may produce such noise due to insufficient transmission fluid.
13) Limp Mode
When your gearbox goes bad, your vehicle’s computer may trigger the limp mode. The limp mode helps to reduce the chances of transmission failure.
In limp mode, the main computer of the car identifies an issue and limits the car to a single gear (commonly the third gear) to avoid further damage to the gearbox. As a result, you can’t operate the vehicle in any other gear.
14) Automatic Transmission Doesn’t Pull
Inadequate power or difficulty pulling the vehicle may be caused by a damaged torque converter. Alternatively, it could be due to worn clutch plates that require replacement.
15) Jumping out of gear
If your car suddenly jumps out of gear while moving, it may be a sign of a failing gearbox.
Causes of Bad Gearbox
- Low transmission fluid: Low transmission fluid is one of the major causes of gearbox failure. Sufficient transmission fluid is necessary to properly lubricate the moving parts of the gearbox and prevent them from overheating. When the fluid becomes too low, it may lead to poor lubrication, increased friction, and finally damage to the gearbox parts.
- Damaged bearings: The bearings play a crucial role to ensure the smooth working of the gearbox. These bearings may damage with time and lead to increased noise, friction, and possible gearbox failure.
- Use of wrong transmission fluid: The use of incorrect transmission fluid may also cause poor performance and damage to the gearbox. Always use the correct transmission fluid according to the manufacturer’s recommendation.
- Poor maintenance: Your transmission system requires regular service and maintenance to work efficiently. If you will not maintain your gearbox, the contaminants such as dirt and debris may accumulate in the system, leading to unnecessary wear and tear on the internal parts.
- Worn synchronizers: The synchronizers are important to ensure smooth gear changes. These parts of the gearbox may damage over time which may lead to difficulty shifting gears.
- Worn clutch parts: The clutch performs a most important role in ensuring the proper working of the gearbox. The damaged or worn clutch parts, like the release bearing, pressure plate, or clutch plate may badly affect the performance of the gearbox and lead to failure.
- Worn or damaged gears: With time, the gears of the gearbox may be damaged or worn out, particularly if you don’t maintain them properly.
- Damaged torque converter: In the automatic transmission, the torque converter has the responsibility to transfer power from the engine to the gearbox. A bad torque converter may lead to hard shifting gear or poor acceleration.
How to Prevent a Bad Transmission
- Ensure regular maintenance of your transmission
- Properly engage the parking brake before shifting into the park as you park your vehicle on an incline
- Regularly inspect the colour and level of the transmission fluid
- Regularly replace transmission fluid according to the manufacturer’s instructions
- Use the transmission fluid according to the manufacturer’s recommendation
- Service the gearbox regularly
- Don’t drive aggressively
- Maintain proper cooling of your system
- Avoid overloading
- In a cold environment, properly warn up the engine and transmission of your car for a few minutes before driving
- Fix the transmission issues as soon as possible
Gearbox Replacement Cost
The replacement cost of the gearbox varies according to the vehicle model, labor cost, and type of part brand. The average replacement cost of the steering gearbox is from $880 to $1100. In this cost, the costs of the parts are between $720 and $870 while the labor costs are between $160 and $230.
FAQ Section
What is the function of the gearbox?
The main function of the gearbox is to transfer power from the engine to the wheels while controlling gear ratios to permit for optimal engine efficiency and vehicle performance under different driving situations. It assists in transforming engine speed to wheel speed, enabling reverse movement, giving torque multiplication, and optimizing engine operation. It helps to increase or decrease the vehicle speed.
How to protect my vehicle gearbox?
The gearbox is a major part of the vehicle. It helps to increase or decrease the vehicle speed. You can protect your car’s transmission by taking precautions such as regular inspection, regular maintenance, keeping the cooling system in good working order, regularly inspecting the level of the transmission fluid, inspecting the transmission, and investing in annual car inspections.
How to make the gearbox last longer?
You can improve the service life of the gearbox by inspecting your transmission fluid regularly, driving carefully, regular maintenance of the gearbox, and having it serviced at least once a year.
What are the symptoms of a bad transmission?
- Fluid leakage
- Dragging clutch (manuals)
- Check Engine Light
- Poor response from the gearbox
- Watch out for gear slippage
- Abnormal Noise
- Car struggles to change gear
- Shaking, Jerking, or Grinding
- Burning smell
What causes car gearbox failure?
- Low transmission fluid
- Damaged bearings
- Use of wrong transmission fluid
- Poor maintenance
- Worn synchronizers
- Worn clutch parts
- Worn or damaged gears
- Damaged torque converter
How to fix gearbox problems?
- Adding more transmission fluid if needed
- Fixing the fluid leaks
- Replacing the damaged bearings
- Don’t use the wrong transmission fluid
- Ensuring proper maintenance of your gearbox
- Replacing worn synchronizers
- Replacing worn clutch parts
- Replacing the damaged torque converter