A whistling gearbox is a sign of impending failure. The main parts are no longer protected and start to clash and wear. We recommend that you contact a professional quickly to check the quality of the oil and the system’s mechanical components before the damage is dramatic and costly.

Gearbox operation and whistling

The gearbox is an integral part of the car’s mechanical system.

In order to function, a combustion engine causes an explosion. And the resulting heat will provide the power needed to activate the system. The gearbox is the intermediary between the raw energy created and the vehicle’s wheels; therefore, the driver can reduce or increase power by operating the gear lever. 

The gearbox works are as simple as that of a bicycle with its chainring and derailleur system. This means that by simple manipulation, a fork will hook up to a sprocket, which in turn is connected to a shaft. To put it simply, engaging the former or the latter means locking one gear rather than another. The parts simply fit together smoothly. 

Therefore, a whistling sound in the gearbox is an evil omen. It means that abnormal friction is occurring or those specific components are damaged. You should contact a professional immediately. 

Gearbox whistling: causes and consequences

A whistling gearbox is a sign that a breakdown is imminent. You should not take the matter lightly.

The noise can be heard at its loudest when you shift into first gear. When you hear the first hissing sound, the system starts to suffer and deteriorate, and you must take action. This is a so-called slow failure, which means that the mechanics are slowly wearing out until they break down completely.

The causes of gearbox whistling can be: 

Lack of lubricant: the oil in the system may be defective because it is loaded with a harmful material. A leak is also possible. In concrete terms, whistling occurs when the parts come into contact during operation. They are no longer immersed in the dense material that protects them from wear. 

Damaged parts: gears or bearings may be worn or corroded. In this case, you must replace them.

Gearbox maintenance or oil change

Car manufacturers do not recommend a time limit for servicing or changing the oil in gearboxes. However, they suggest that the operation be carried out as soon as the system is modified, whether a change of drive shaft or clutch. 

What to do if the gearbox whistles?

If you hear a whistling sound in the gearbox, you must take action. Go to a professional right away or, if you have expert hands, do these three things: 

1. Change the oil so that you can determine whether the oil is defective. 
2. Check the gearbox for leaks. 
3. Check the condition of any parts that might squeak if damaged. Have them replaced if necessary. 

How do I change the oil in the gearbox?

Changing the oil in the gearbox is a simple operation: 

• Remember to raise the vehicle. 
• Under the car, find the plug that is located under the gearbox. 
• Place a tray underneath and unscrew it so that the liquid drains out. 
• Remember to clean the plug, which attracts all the dirt. 
• Close it again. 
• Open the filler cap and pour in the valuable new fluid. 

Repairing the gearbox

A gearbox is an expensive part of the car’s mechanical system, so it is best to take care of it. 

An oil change and system check by a professional is essential. 

Changing a gearbox component, such as a damaged bearing or pinion, is often impossible. In this case, you will be offered the possibility of replacing the entire gearbox.