5 Potential Signs of a Bad Transmission

November 30th, 2023 by

5 Potential signs of a bad transmission

A vehicle’s transmission is arguably its most crucial mechanical component, tied only with the engine block. Without a perfectly-working transmission, your vehicle will quickly start to experience some seriously noticeable performance issues.

Transmission repair can be palm-sweatingly expensive, but it doesn’t always have to be. The best way to avoid a hefty service bill is to deal with any bad transmission symptoms ASAP. Let’s check out some common signs of a faulty transmission, and what you can do to fix the issue without breaking the bank.

What is a Transmission?

Before we address common transmission problems, let’s briefly go over what a transmission does, and why it’s so important. Feel free to skip ahead if you already know this bit.

A transmission (or gearbox if you want to sound cool) consists of a series of gear trains, which change depending on driving conditions. It’s linked directly to the engine by a series of belts or chains, and its main job is to regulate the amount of raw power coming out of the motor, which ensures the system is executing the correct amount of RPMs relative to speed.

Without a properly working transmission, the explosive force found inside a typical internal combustion engine would be too great for the vehicle to handle. This would inevitably result in catastrophic engine or drivetrain failure.

Nowadays, the vast majority of transmissions are automatic, meaning the car automatically does the work of shifting through the appropriate gears, based on how fast the vehicle is accelerating. Manual transmissions, on the other hand, rely on the driver to manually change gears, which requires greater care on the driver’s part.

If you’re still a little murky on how it all works, don’t stress on it too much—that’s what certified service technicians are for.

Check engine light

Signs Your Transmission is Going Bad

Now that we have a basic understanding of why the transmission is all-important, let’s go over some telltale signs that you may be due for transmission service.

Check Engine Light

Right off the bat, we’ll go ahead and address this painfully obvious sign that something may be amiss. Many newer vehicles have more detailed onboard diagnostics, but there are still a ton of cars on the road that only have the classic check engine alert, which is usually yellowish-orange in color and resembles the picture at the top of this section.

In order to diagnose transmission troubles, you’ll have to use a vehicle code reader—typically, these are free to use at any auto parts store or mechanic shop. The scanner will give you a specific code, and you’ll be able to diagnose the issue from there. Easy peasy.

Also worth noting: if you have a check engine light on, and you’re experiencing any of the following issues at the same time, it’s quite likely a sign of transmission problems.

Leaking Transmission Fluid

In order for all the hundreds of small parts inside your transmission to work properly, they have to be properly lubricated with a specially formulated transmission fluid. If the transmission fluid is too old, or if there isn’t enough of it in the system, the vehicle won’t work properly.

New transmission fluid is generally dark red in hue, reminiscent of your typical red wine. No other fluids have this color, so if you see a pool of reddish fluid under your car, it’s likely you have a leak somewhere in your transmission and this must be addressed immediately.

Transmission fluid can also be more of a gunky, blackish color, similar to old oil. This is a sure sign that you’re due for a fluid replacement. Checking the trans fluid yourself is possible with some vehicles using the corresponding dipstick, but many vehicles require a technician’s help to do so—one of the many reasons why regular checkups are pivotal.

Low or old transmission fluid is one of the main causes of transmission problems, especially when the issue goes unaddressed for an extended period of time. The best thing you can do for the longevity of your transmission is to schedule transmission service to ensure that your fluid levels are adequate.

A Burning Smell

It goes without saying that your car isn’t really supposed to be emitting any nasty odors unless maybe you left a breakfast burrito or something in there. The smell of something burning can be caused by a few different things. Sometimes, it’s a symptom of old or low transmission fluid.

Burning smells can be caused by old ATF (automatic transmission fluid) that has collected a bunch of clutch debris or other substances. Trapping transmission detritus is actually exactly what the fluid is designed to do, and clearing this blockage out is part of why fluid must be replaced every so often.

However, just because you smell something burning, doesn’t necessarily mean it’s your transmission—it could be another culprit, like burning motor oil. Most sources say that burning transmission fluid has a distinct odor, more akin to burning rubber. Unless you’re already familiar with the distinct odor, it’ll likely require a professional diagnosis, so if you notice any kind of acrid smell that wasn’t there before, consider it your last-minute warning to get to a shop as quick as you can, because it could very well be a low ATF symptom.

Strange Noises

Much like weird smells, hearing odd sounds coming from your car can mean hundreds of different things, depending on the specific sound, and when they tend to happen.

Humming or whining are common noises associated with a faulty transmission, especially if you drive an automatic. A persistent noise when the car is idling or accelerating will likely require an expert set of ears and eyes to find the problem because it could be anywhere along the drivetrain.

A sudden clunking or other loud noise when shifting gears is another strong sign of potential transmission failure. These noises are commonly heard in manual gearboxes, but they can be present in automatic models as well.

Excessive noise when the vehicle is in neutral is yet another classic sign your transmission is in need of service. This often indicates that you need transmission fluid. If you’re noticing an overarching message here, we’ll reiterate: keep that transmission fluid serviced.

Shifting difficulty could be a sign your transmission is going bad

Shifting Difficulty

One of the most common signs that your automatic transmission isn’t doing its job is delayed shifting.

What this feels like in an auto transmission is, when you use the gear selector to go from park to drive or drive to reverse, it may take the car a few seconds to engage the proper gear. This delay may be accompanied by a noticeable noise. The cause could be something simple like old fluid, but it could be something more serious, like worn-out gears, or a symptom of a torque converter going bad.

Another notable phenomenon is the transmission slipping out of gear. You can tell that your transmission is slipping when you press on the gas and you hear the engine revving, but the car doesn’t accelerate like it’s supposed to. Some folks say that a slipping transmission feels similar to the feeling of driving over a sudden patch of ice. This is a surefire sign to get your vehicle to a shop because it can be dangerous, especially at higher speeds.

Schedule Nissan Transmission Service Near Birmingham

Regular transmission service is important no matter what you drive, so it’s important to stay on top of it. Acquainting yourself with how to check your car’s transmission fluid levels can save you a huge headache in the long run. Be sure to check your owner’s manual, or have one of our friendly service technicians show you how.

Hallmark Nissan’s service department is at your beck and call for any auto diagnostics you may need. Schedule your service with us online, or just give us a call at (205) 324-3371to set up an appointment, and be sure to ask about our killer service specials while you’re at it.

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