The gearbox is one of the most important components of your car, and it plays a pivotal role on how the car functions. It makes mobility possible by allowing you to change gears and move from one point to the other.
Gearboxes are of two types: manual and automatic gearboxes. For this article, we’ll be focusing on the automatic gearbox, also referred to as “automatic transmission.”
Several components of the car require proper attention and servicing to enhance its longevity and performance. The automatic gearbox is one of such components because this part of your car is quite complex, expensive to fix and as such should be taken proper care of.
Like other components of a car, the automatic gearbox tends to develop faults after a certain period of usage. Since the component is expensive to replace, it becomes worrisome when it fails. To avoid this, you should be conversant with some warning symptoms of a bad automatic gearbox as this will help you make a diagnosis on time, to avoid complex and expensive repairs or replacements.
This article will explore the symptoms of a bad automatic gearbox and other information you need about the automatic gearbox.
What is the Automatic Gearbox and What Does it Do?
The automatic gearbox also known as the automatic transmission is a component of your car that makes it possible to change the RPMs of the engine. It is the type of gearbox that will change gears automatically while the vehicle is moving and relieve the driver from the burden of manually changing gears.
The automatic gearbox is a multi-speed transmission unit in internal combustion engines. It is easy and safer to use and allows you to concentrate while driving instead of having to change gears and making adjustments, as it is when using a manual gearbox.
An automatic gearbox has a self-shifting feature, eliminating the need to manually shift gear, thus operating without a clutch pedal. It combines torque with the gearset to create the desired gears for a moving vehicle. For a vehicle to move effectively—climb a hill and drive properly while accelerating or with load, a large amount of torque is required and with the aid of the automatic gearbox, a good amount of torque is produced to facilitate driving over a high-speed range.
An automatic gearbox is made up of 8 main parts which include the transmission casing, impeller, torque converter, turbine, stator, planetary gears, brake band, and torque converter clutch.
How does the Automatic Gearbox Works?
The working principle of the automatic gearbox is very different from that of a manual gearbox.
Most automatic gearboxes are made up of a set of gears known as the planetary or epicyclic gear train. The gear set constitutes the planet gear, the sun gear, and the ring gear. The sun and planet gears are connected to the ring gear to enable an automatic gearbox to produce different gear ratios.
The automatic gearbox makes use of hydraulic power in shifting gears. This process will combine torque with gear sets to provide an automatic car with a different range of gears.
The car engine is connected to the gearbox and a torque converter and pressurized fluid is used to move power from the engine to the gears. The torque converter takes the role of the gearbox clutch present in cars with a manual gearbox.
In an automatic gearbox, the gear stick and clutch are substituted for a simpler device known as “A Shifter” with three standard options (park, drive, and reverse) for shifting gears.
Symptoms of a Bad Automatic Gearbox
The gearbox is one of the most expensive components to replace in a car. Hence, it’s important to have it checked once you notice the slightest fault. When the automatic gearbox is failing, you’ll notice some of the symptoms listed here.
When the gearbox is faulty, you will begin to feel some unusual movements in your car while the component is shifting gear. Your car might jerk or clunk because of this.
The transmission fluid is an important part of an automatic gearbox or transmission. It is usually the red fluid in the transmission system and can leak from broken seals, gaskets or cooler lines. Leaking transmission fluid indicates that there is an issue in the automatic gearbox.
Check engine light beams
Almost every component in your car is connected to the engine and when there are problems with them, the check engine light will be triggered.
The automatic gearbox has several sensors installed in it, when there is a problem, a signal is sent to the engine control unit which causes the check engine light to beam.
A faulty pressure pump or slipping clutch in the automatic gearbox will cause a slightly delayed transmission when you engage the shifter. When you start experiencing this, it is important to take your car to an auto repair shop for inspection.
A faulty automatic gearbox will cause the gear to slip. When the gearbox is faulty, it might send wrong signals to the ECU to change gears. The transmission unit responds abruptly to this and might return the gear to the previous one or back to neutral.
Noise from the automatic gearbox
When your automatic gearbox is faulty, you will notice a kind of rumbling, humming, or whining sounds coming from the transmission unit.
The noise could mean that some rotating components are loose or worn out. These sounds are disturbing and can damage other internal components of the automatic gearbox. You must fix this ASAP!
The transmission fails to respond
When you try to change to park, drive, or neutral modes on the automatic gearbox and it fails to respond, it signifies that there is a problem that needs urgent attention in the system.
You might put your gear in drive or reverse mode, but it does not respond immediately or at all. These problems are usually a result of old or contaminated transmission fluid in the system or a problem with electrical components.
Burning smell from the transmission unit
The transmission fluid is an essential part of the automatic gearbox. It plays a huge role in ensuring the complex and expensive automatic gearbox system functions efficiently by providing the required lubrication.
Over time, the transmission fluid will reduce or dry up which will require a refill. If this is not done, there will be friction in the transmission system which will initially cause parts to break down, build up debris and later lead to a complete breakdown of the system. At this time, if you engage your gear, it will not respond.
How to Avoid Automatic Gearbox Problems
The automatic transmission is a complex and expensive component to repair and as such must be taken good care of. When you pay good attention to your vehicle, you’ll notice any impending problem and fix them at that early stage.
Here are a few helpful tips to prevent early or unexpected automatic gearbox problems.
- Service your vehicle as required or as recommended by the manufacturers.
- Do not wait until you find a pool of transmission fluid under your engine. Inspect the component regularly to discover minor cracks or tears.
- Look out for any unusual noise that might come out from the engine.
- If you perceive burning smells from your car, take it to an auto repair shop for inspection.
- Do not overlook the check engine light when it illuminates on the dashboard. You can try diagnosing it by using an OBD scanner to scan error codes or by taking it to a professional.
Cost of Replacing an Automatic Gearbox
The automatic gearbox is a large, complex, and usually expensive component to replace. Fortunately, most times, you might not need to change the entire gearbox.
The problem might be with either the torque converter assembly, the planetary gears, or turbine, etc. and you’ll be required to work on just the damaged components. Whereas, replacing or rebuilding the automatic gearbox depends on your car type and model and can cost between $800 to $6000 for both parts and labor.
Frequently Asked Questions
Where is the automatic gearbox located?
The location of the automatic gearbox varies depending on the placement of your engine which is usually determined by the model and make of your vehicle. In some cars, the engine is placed sideways while in some it is at the center of the front part of your vehicle and connected to the driveline. For front-wheel drive vehicles, the automatic gearbox is found in a location under the engine in the hood of your car. Whereas in rear-wheel drives, the gearbox will be under the dashboard region while the shifter which enables you to put the car in park, drive, reverse, or neutral mode is inside the cabin between the driver and passenger’s seat.
Why is the automatic gearbox failure so significant?
The gearbox is a very essential component of your car, and it is pivotal for moving your car in the direction you want and at the desired speed. Due to the role the automatic gearbox plays in your car, its failure is usually very significant. If the automatic gearbox fails, your car might stop moving or be unable to perform certain functions. It will be dangerous if you keep using the car in this condition. A faulty gearbox can make your car unusable.
What should I do if I start having problems with my automatic gearbox
The gearbox or transmission is a very complex component, and it is always advisable to take your vehicle to an auto repair shop when you notice any issue emanating from it. Trying to fix this on your own, especially when you don’t have any knowledge or experience working on cars will rather lead to more complications.