Transmission Whining Noise in Park and Neutral – What's This?

Whining noise from your transmission when in Park or Neutral may mean that there are problems with one or two bearings, low fluid level, or issues with electrical connections. The transmission may whine when there are problems with almost any part of it. Of course, it will also depend on the type of your transmission.

Noisy transmission highlights

• Level of importance:Medium
• Reasons:bearing problems, gears grinding, torque converter issues
• Needed expertise:High
• Needed tools:Professional tools set
• Time taken:5-10 hours
• Can you drive? Not recommended
• Possible issues: Serious damage to gearbox, gears failure.

How to understand your transmission is whining?

When something starts whining in your car, it's not that easy to identify the sound and understand which exact part is making it. In most cases, whining will come from a worn-out bearing. But bearings are not only found in the transmission. There are wheel bearings, engine bearings, alternator bearings, etc. And all of them can whine.

Actually, alternator whining is very often mistaken for transmission sounds. But when it comes to whining only in certain transmission modes, hesitations are gone - your sounds are emanated exactly by the damaged transmission.

Here are some signs that may prove it:

• the sounds are heard when the car is idling or driving - this way you can see that the wheel bearings are not the culprits;
• the sound may be heard in Park and Neutral but goes away when you shift to Drive or Reverse - you may exclude the alternator at this stage;
• the sound isn't getting worse for a long time - usually, it means that some minor bearing in the transmission is faulty;
• the whining sound comes exactly from the side where the transmission is mounted in your car;
• the whining may be stronger or weaker depending on the temperature - this is also the behavior of the transmission.

But you can't say for sure that it's all about the transmission until you have the car inspected. Your engine also has several bearings and they may whine exactly the same way. Their whining will also depend on the engine RPM and loads. So, it's almost impossible to identify the source of whining without professional inspection.

But still, if you notice that the whining sounds go away once you shift to Drive or Reverse, you should start with the transmission.

Common reasons for whining sounds in P and N

So, whenever you put your transmission in Park or Neutral, the same process inside the transmission happens. These two modes are exactly the same for the transmission with one difference - the P mode will apply the parking pawl which is the special lock for the transmission that doesn't let your car move when in Park.

The transmission itself stays in Neutral whether it's in P or in N. It means that the engine will rotate the torque converter but the torque will not be sent to the wheels and no gears will be applied.

Here are the reasons for such behavior:

1. Transmission bearings

Actually, any bearing in the transmission may whine. There are several bearings including the main one. No matter which exactly bearing whines, you will need to take the transmission off the vehicle and troubleshoot each of them. This is not a DIY task, so in this case, you will need professional help.

Bearings tend to whine when they are worn out. But if the problem is with the main bearing, you will keep hearing the whining sounds even when R or D modes are applied. So, in your case, when you only hear the noises in P or N, it may be some other bearing that whines when in Neutral but stops whining when under load.

2. Torque converter

Your torque converter may whine if it's installed improperly. If you had the transmission repaired or taken off recently, go back to the shop and say that something is wrong with the torque converter. Most likely, the position of the converter is wrong and it whines in Park or Neutral when rotating without the load.

If your torque converter started whining without any repairs, it may be the pump. The torque converter has a pump in it that creates the needed pressure of the fluid in the system. The pump has rotating elements in it and may be whining if something goes wrong with it.

3. Low transmission fluid level

If the level of the transmission fluid is low, it's not a surprise that your transmission is whining or making some other noises. The problem is that the transmission fluid is a very important factor in the proper work of the unit. If the fluid is low and the pump can't create the proper pressure, the whining noise may occur.

Unfortunately, the majority of modern transmissions don't allow you to easily check the fluid level just by using the dipstick. If you suspect that the level of transmission fluid is low, you should go to the shop or to the dealership. They will check the level and top up the fluid if needed.

4. Other minor problems

The whining noise may also occur when the fluid pressure in the system of your transmission is not correct. This may happen because of some blockages in the hydraulic units, contaminated or bad fluid, or issues with fluid passages in the system that don't allow the fluid to circulate properly.

If this is the case, you should obviously have the transmission inspected, locate the reason, and then find the best way to solve the problem. Changing the fluid and filter may help, but you should check that all important parts of the transmission are working properly.

Can you drive when you hear whining in Park and Neutral?

If the whining noise is not intensive and it has developed over time, you may still drive the car. But if the noise appeared just after one night and now you start the car to hear serious noise that wasn't there yesterday, it's not a good idea to ignore this.

The problems with the transmission may appear suddenly and without any symptoms that could tell you earlier about these issues. If you keep driving a car with a damaged transmission, chances are that you will require a new transmission because of the fatal damage.

If you don't see any error messages and warning lights on your dash, you may try driving carefully. But I strongly recommend choosing the manual shifting mode and also making an appointment in the dealership as soon as possible. Driving your car is only OK to avoid calling a tow truck.

Inspection and repair of your transmission

When it comes to a modern automatic transmission, there is not much you can do on your own in terms of inspection and repair. This is a completely closed unit that you can't even check the fluid level. When it comes to some weird noises and behavior, there is just nothing you can do.

But there are some things you can keep doing to prevent your transmission from failing:

• change fluid and filter about once every 60,000 miles;
• be careful when towing - remember the towing capacity limitations of your vehicle;
• let the transmission warm up when you start driving - be careful in the first 5-10 minutes after you start the car in the morning;
• don't abuse the transmission unless it's made for sports;
• avoid DIY repairs if you don't have the needed expertise and tools for this.

If you already hear the whining noise, these recommendations will not help you get rid of it. It's still important to remember about the rules of using the transmission, but when the problem has already started, you will need to repair the transmission.

For this, I strongly recommend you go to the dealership or to the trusted and reputable independent repair shop. Ask the mechanics to inspect the transmission and find the culprit of this noise. Unfortunately, the repairs are going to cost you quite a lot of money because any work with the transmission is labor-intensive.

Final thoughts

People keep asking me a lot of questions about the transmission repairs when it makes whining noises. You need to understand that even taking the transmission off the car is a huge challenge for a person without proper tools and experience. I never recommend any DIY repairs when it comes to the transmission.

I hope now you can manage to cover the problem with the whining noise in the transmission. If you still have questions, ask them in the comments below!