What are the symptoms of bad Gearbox? | Signs of Bad Transmission

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 symptoms and causes of a bad transmission.

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.


Most car engines have high operational rpm, so transmission allows the machinery to work effectively and also helps to slow or shut the machinery.

Signs of bad Gearbox

As the gearbox goes bad, it generates one of the below-given signs:

  1. Fluid leakage
  2. Check Engine Light
  3. Poor response from the gearbox
  4. Abnormal Noise
  5. Shaking, Jerking, or Grinding
  6. Burning smell
  7. Car struggles to change gear
  8. Watch out for gear slippage
  9. Dragging clutch (manuals)

1) Fluid leakage

ATF (Automatic Transmission Fluid) is found in the vehicle transmission system. This fluid helps to decrease friction between the gears and prevents overheating. If your vehicle ATF starts to leak, it can lead to some serious hand problems.

In fact, ATF leak is one of the major causes of automatic transmission system failure.

As the Automatic Transmission Fluid leaks, you may notice bright red fluid pooling under the 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.

2) Check Engine Light

Your vehicle Check Engine Light can indicate different problems, but it can also mean that the transmission is defective.

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.  

3) Poor response from the gearbox

The poor response or inefficient working of the gears is one of the common symptoms of a bad transmission system. In such condition, you may face problems with gear change.

Signs of hesitation or total refusal to shift gears may 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.

4) Abnormal Noise

Abnormal noise is also a clear symptom of the bad gearbox. If your gear box is making noises such as buzzing, howling, rattling, or humming that you have never heard before, there may be a problem with your gear box.

The gearbox contains multiple moving parts. This unexpected noise may occur due to a damaged part.

Although the symptoms of transmission bearing failure in manual transmissions tend to be “clunk,” while automatic transmissions often buzz or hum.

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 the inspection. 

5) Shaking, Jerking, 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 transmission mount or a bad engine may also cause clunking and jerking.

6) Burning smell

The burning smell may occur due to leakage of transmission fluid. Smoke can also be seen.

As the gearbox goes bad, it doesn’t receive lubricant according to its requirements.  

7) Car struggles to change gear

This can be due to low or incorrect transmission fluid, a solenoid failure, a sensor failure, or a clogged filter.

8) Watch out for 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.

9) Dragging clutch (manuals)

The dragging clutch occurs when the flywheel and clutch disc do not unlock as the clutch pedal is depressed.

The manual gearbox may also slip out of the current gear, which may generate a grinding noise.

FAQ Section

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 gear box, and having it serviced at least once a year.

What are the symptoms of a bad transmission system?

A bad transmission system produces one of the below given symptoms:

  1. Fluid leakage
  2. Dragging clutch (manuals)
  3. Check Engine Light
  4. Poor response from the gearbox
  5. Watch out for gear slippage
  6. Abnormal Noise
  7. Car struggles to change gear
  8. Shaking, Jerking, or Grinding
  9. Burning smell
Read More
  1. Signs of bad Brake Shoes
  2. Working of Fuel Injector

Leave a Comment