Groaning Noise When Reversing (The Exact Reason Found)
When your car makes a groaning noise when reversing or backing up, it means something is wrong with the vehicle. In order to get rid of this problem, it is very essential to identify the cause of the issue. This squealing, grinding, clunking, whining or creaking noise from the car when turning or braking in reverse. This guide will walk you through the most possible causes that produce groaning noise from the car when in reverse. So, stay connected.
Groaning noise when reversing can be due to a bad braking system, damaged sway bar bushing, collision of dust shield with the brake rotor, and broken constant velocity (CV) joints.
Before diving further, I have also written a detailed guide on humming noise from Ford when accelerating. I would highly recommend you to check this out as one of the possible reasons for groaning noise when reversing can be a damaging CV joint. In that guide, I have explained it in detail.
Table of Contents
Why Is Car Making Groaning Noise When Reversing?
Car makes a groaning noise when reversing or backing up due to the following reasons:
- Brake pads are dragging or worn out
- Faulty wear tab of a brake caliper
- Sway Bar Bushing has dried out
- Retaining clip on the brake is loose
- Dust shield is touching the drum or disc
- A tiny rock has stuck somewhere around the wheel or brake
- Damaged engine mounts and strut mounts
- Damaged CV joint
Bonus Read: Car jerks when shifting to reverse
1. Brake Pads Are Worn or Stuck to Your Disc
The most common cause of moaning, grinding or groaning noise from the car when reversing is that the brake pads are worn out. When the brake pads rub against the disc (rotor), the disc is heated up by friction.
As the heat builds up, the disc expands causing it to deform and rub against the brake pads. As a result, a loud grinding or grumbling noise occurs. This noise may be very annoying and is often accompanied by vibrations, especially in older cars.
Here is what a user says:
“I have experienced this problem myself with my 2003 Audi A3. When reversing, the rear brakes would make a loud squealing noise. The groan was caused by the word brake pads rubbing against each other. The squeal was so loud that it could be heard even at a distance of about 200 meters! A fix was to replace the word brake pads. Afterward, the squeal did not happen again.”
When a brake pad becomes jammed or stuck to the rotor, it also emits a grinding or creaking sound when braking at low speed or reversing. Brake pads are stuck when there is no grease left in the sliding pins.
I will recommend Sil-Glyde to lubricate the sliding pins of brake calipers.
Moreover, brake pads and rotors can also develop rust film that can also be the cause of a squealing sound when reverse. You can use wire brush to remove rust film from the rotor and brake pads. Since brake pads scrub off the rust from the rotors when they rub against them, a groaning sound can produce. So, you should grease the brake pads with this Prematex Ceramic.
If everything is dry and you can hear a groaning noise when reversing your car, it means brake pads need to be lubricated, and if you hear groaning noise after rain, the moisture buildup develops rust that could cause whining or groaning noise.
2. Faulty Wear Indicator tab of a Brake Caliper
Wear tab is also called brake pad squealer. A wear tab can also cause a moaning noise from car when backing up. On the edge of the brake pad, you will see a small metal tab that ensures that the braking system works effectively when a brake is suddenly applied in unexpected situations.
The wear tab is meant to scrape the disc when it’s time to replace the brake pads. As the brake pads wear, the metal tab rubs against the rotor, causing a squealing sound when the brakes are applied during reversing.
You can watch the below video in which the guy has explained everything about the wear tab. As the brake pad wears out, the wear tab is designed in a way that it starts touching the brake rotor and producing a squealing sound when reversing, thus indicating that the brake pads need to be replaced.
3. Sway Bar Bushing Has Dried Out
Damaged sway bar bushing can cause groaning noise when turning and reversing. A sway bar is used to keep the vehicle’s wheels aligned when it makes turns or takes off-road. The sway bar is connected to the suspension arms that connect the wheel to the body. When the car is going over uneven terrain, the suspension arms will flex, allowing the wheel to stay on the ground.
Sway bar bushings are a kind of rubber or polyurethane bushings that are used to reduce vibration. Sway bar bushings perform as a fulcrum of the sway bar as they keep it attached to the frame of the vehicle. If the sway bar bushing breaks, it will also cause clunking or squealing sounds from the car.
To understand better, I have found this video helpful in which the guy is replacing the cracked rubber sway bar bushing.
The most recommended bushing for a sway bar is Moog Stabilizer Bar Bushing.
4. Retaining Clip On the Brake Is Loose
The retaining clip keeps the brake pad from sliding off the disk and into the caliper. It holds the pad in place and helps prevent it from becoming loose and falling off. It is either made of aluminum or steel.
If a retaining clip that snaps into the brake piston is slightly loose, a light brake pedal pressure when reversing a car would often produce the most heinous groaning sound. However, when you increase the brake pressure, it will go away as the brake pad will firmly squeeze against the rotor.
5. Dust Shield Is Touching The Disc
Dust shield can also cause groaning or creaking noise from the car when reversing without applying brakes. Dust shield is on the back of the brake disc that protects the brake rotors, calipers, and pads by shielding them from environmental particles, such as road grime that can affect braking performance. Dust shield also prevents brake dust from getting all over the suspension components.
Now, the issue with a dust shield is that it is a thin bendable piece of metal. The dusting shield easily bends against the brake rotor and generates a scraping sound when reversing.
5. A Tiny Object Has Stuck Somewhere Around the Wheel
A small stone that is caught between the wheel and the brake pad may result in grinding or squealing noises. The noise is caused by the stone pressing against the wheel or brake pads and rubbing against them. You might hear a loud clunking sound if the stone is large enough. Even if you don’t apply the brakes when reversing, you will hear that grinding noise when reversing.
Moreover, also check if there is any loose piece of plastic hanging under the car that is rubbing and causing grinding noise when reversing.
6. Bad Motor Mount
If you are hearing a single loud knock or bang when putting your car in reverse from parking mode like this, the chances are that motor mounts are bad.
Motor mounts are used to dampen and isolate the vibrations of the engine from the rest of the car. They usually consist of rubber cushions that are attached between the engine and the frame of the vehicle. A bad motor mount will appear torn or crushed. Motor mounts can become so bad that they can actually damage the axles on front-wheel drive cars.
One person was facing clunking noise when reversing. He replaced the driver-side engine mount and fixed the problem.
The number of motor mounts depends on the size of the vehicle. Usually, the vehicle has 2 to 4 engine mounts.
To verify the bad engine mounts, pop the hood, and ask your friend to shift from parking to reverse while you watch the engine. If the engine moves a lot when it goes into reverse, chances are that it means that the motor mounts are bad.
Reverse Gear Noise Is Normal
Reverse gear is a spur gear, while other gears of a transmission system are helical gears. The spur gear is lightweight and simple in design compared to the helical gear.
When a car is shifted to reverse mode from parking mode, we don’t really need a helical year because we are transitioning our vehicle from a standstill mode. Helical gears are important when the car is in driving mode and is shifting from one gear to the other as helical gears allow even distribution of the load.
Spur gears mesh with each other abruptly and do not allow a smooth load distribution like helical gears. Due to this reason, whining noises are sometimes observed when reversing.
You can watch the below video for a better understanding:
Final Thoughts
The groaning noise heard while reversing a car can be caused by a variety of issues ranging from a bad braking system to bad shocks, engine mounts, bad front axle joint (CV joints), and rusted-out wheel hubs.
Brake pads are designed to wear out after a certain amount of use. When brake pads are worn, the brake discs may stick to them and produce noise. When brake pads wear down, they should be replaced. The rotors should also be checked for excessive wear and should be replaced if they’re damaged.
