Whining noise when accelerating and decelerating is quite frustrating, troubling, and unnerving. It makes you look so embarrassed when you start your car and accelerate it in the morning. It could be so loud that your neighbors will be staring at you.
Is it normal for transmission to whine? What could be the actual cause? Many vehicle components wear over time under normal use. The transmission components are not different.
They wear out over long use and start showing issues. Once this happens, the only remedy is to track the cause and fix it before it escalates to a total tranny failure.
This article will discuss the causes of transmission whining noise when accelerating. We’ll also explain how to fix it.
What Causes Transmission Whining Noise When Accelerating?
There are several causes of manual and automatic transmission whining noises in a vehicle. It’s essential to note that all whining noises are not from the transmission. Here are the causes of transmission whining noise when accelerating.
Failing transmission oil pump
A transmission oil pump is an integral part of the transmission unit. It serves the critical purpose of providing lubrication to the valve body and other essential internal tranny components. It also transports transmission fluid to the tranny cooler, cooling the fluid.
One of the common signs of a failing transmission oil pump is a whining noise when driving. So, if you ask, ‘why does my transmission whine when I accelerate?’ It could mean you have a failing transmission pump. A notable sign that it’s a failing tranny oil pump is consistent at all speeds.
Also, there will be metal shavings in the bottom of the transmission crankcase at removal. This means the tranny oil pump is wearing out. A failed tranny oil pump is usually caused by dirty transmission fluid causing the blockage, a bad front seal causing transmission leaks, and an extremely clogged transmission filter causing restricted fluid flow.
It can also be caused by poor lubrication causing friction, defective transmission crankcase causing leaks, etc.
Lousy planetary gear set
The planetary gear set comprises the sun gear, the ring, and the planetary gears. These components work in harmony and allow the transmission to function properly.
Over time, the planetary gear can wear off and cause transmission whining noise in the park and neutral. The noise will be obvious when driving and increases as the vehicle speed increases.
The function of the planetary gear set is to change output direction such as reverse, increase output speed, and lower torque used for overdrive, and decrease output speed and increase torque.
Low transmission fluid
The importance of the transmission fluid can not be overemphasized. It lubricates and cools the tranny and prevents it from overheating. If the fluid gets too low, it’ll cause strange noises from the transmission. These noises include whining and grinding noises because of excess friction on the moving internal parts.
Whenever you notice a low tranny fluid, check if there’s a transmission fluid leak and fix it before topping the transmission.
Clogged transmission filter or restricted fluid passage
When there’s a clogged transmission filter or a restriction on the transmission passages, it can cause several tranny problems. Transmission fluid is essential in all tranny units because it lubricates internal components. Besides, it cools the transmission.
The transmission needs 50-70 PSI of pressure to circulate the fluid to every nook and cranny part of the tranny. It also helps to keep the internal parts functioning properly. For example, a failing torque converter can make a whining or grinding noise because of improper lubrication.
So, if you’re wondering ‘what does a whining noise when accelerating mean,’ it could mean you have a restricted transmission fluid passage. Usually, a failing torque converter will continue to whine until it completely fails. It also causes the car to make a whirring noise when driving and idling.
Worn input shaft bearing
This is an important yet less discussed component of a transmission unit. It is an internal bearing within the transmission housing. The input shaft connects to the output with a set of bearings. These bearings allow the output and input shaft to rotate at varying ratios. If these bearings fail, the transmission will make a whining noise at idle, neutral, and gear.
Bad throwout bearing
Throwout bearing is a critical tranny component in manual transmissions. If you hear a whining noise at idle when the gear is not engaged, there’s a chance that it’s coming from a defective throwout bearing.
However, this noise intensifies when operating the clutch rather than idling or driving.
Worn clutch or flywheel
Clutch pressure plates and discs in manual transmissions do not last the vehicle’s life. When the clutch systems begin to wear, they’ll emit strange noises like grinding and whining sounds. When they make these noises, they need resurfacing or replacement.
Having seen the causes of transmission whining noise, what’s next? Let’s look at how to stop transmission whine.
How Do You Fix A Whining Noise When Accelerating?
Several factors can cause whining noise from the transmission. Therefore, there are several steps to fix it. Here are the steps to fix the transmission whine.
Check transmission fluid level
When you notice a whining noise from your transmission, check the fluid level and ensure it is on the right gauge. If it is below the recommended gauge, top the transmission with the right fluid type.
Clean or replace the transmission filter
The transmission filter serves filtration purposes. It filters the fluid before getting into the oil pump. Over time, the dirt and debris that the filter prevents from getting into the oil pump will clog it.
The second step to take in case of whining noise from the transmission is to check the filter on an automatic transmission. The transmission filter is located inside the crankcase. Drain the transmission fluid with a sizable wrench. After that, unbolt the crankcase.
Once the crankcase is out, check if there are metal shavings. Also, check if there is debris or particles on the tranny filter.
If you find debris on the filter, unbolt the bolts holding it. Wash it with a solvent or gasoline and allow it to dry. If the filter is blocked, you may replace it. After that, reinstall it following the reverse process.
Contact your mechanic
Since the transmission is a complex vehicle component, it requires an experienced auto mechanic to do further diagnostics and repairs. Contact your mechanic to diagnose and fix the underlying issues.
On manual transmissions, the mechanic may have to replace the defective throw-out bearings, worn clutch pressure plate, and disc. In most cases, replacing these components will fix the whining noise.
On automatic transmissions, Further diagnoses and repairs will require dropping the transmission and disassembling it to access faulty components.
If you hear a grinding noise from your automatic tranny, read this detailed article on the causes and solutions of automatic transmission grinding noise when put in gear.
Q: Is a whining transmission bad?
Generally, a whining transmission is bad. It shows an underlying tranny component issue that needs attention. If the whining increases in reverse, you have a restricted transmission fluid passage.
A clogged transmission fluid passage can be extremely detrimental to the tranny unit. On an automatic transmission, if the whining noise increases when driving, it’s likely you have a failed torque converter.
Q: Can low transmission fluid cause whine noise?
Low transmission fluid can cause whining noise in both manual and automatic transmissions. If the fluid is too low, the entire transmission components suffer poor lubrication. It becomes obvious when the gear is engaged.
Here, the whining noise you’re hearing is friction between moving internal metal components.
Q: Can a transmission make a humming noise?
Defective or malfunctioning transmission components will emit several troubling and disturbing noises. In automatic tranny, you’ll hear buzzing, grinding, whining, or humming sounds. Defective manual transmissions may make aggressive clucking sounds.
Q: Will a transmission whine in the park?
The transmission pump distributes tranny fluids to every nook and cranny part of the transmission, and it is driven directly from the engine. This means the transmission pump starts working when you turn on the engine.
Therefore, a faulty transmission pump will whine in all gears, including park and neutral. A restricted transmission fluid passage will also whine in all gears.
Q: Can a torque converter make a whining noise?
When a torque converter fails, it’ll emit several noises. At initials, it’ll make a whining sound like a power steering pump with low fluid. A torque converter houses a stator with a series of clutches in its assembly.
If the stator goes bad, the clutches will make rattling noises. It’ll make these noises both in the park and in gear. However, the noise will intensify as you put the tranny in gear.
Q: Is it normal for transmission to whine?
Some vehicle transmissions make a little whining sound under normal operation. Depending on your vehicle make and model, a little whining sound from the transmission could be completely normal. However, you should know your transmission sound to avoid confusing a fault with a normal operational sound.
Transmission whining noise when accelerating shows underlying transmission issues that need urgent attention. However, on some transmissions, little whining noise can be normal. You don’t need to take any action in such a case.
We have outlined the causes of transmission whining noises and the solutions to rectify them. If you’re hearing a whining noise from your transmission, you can get your hands dirty or contact a professional mechanic.