Blog Car Care Advice 13 Reasons Why Your Transmission Jerks (+ 2 Common Fixes)
Car Care Advice

13 Reasons Why Your Transmission Jerks (+ 2 Common Fixes)

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Does your transmission jerk when shifting to the 4th or 5th gear?
Does your car jerk at a low speed or when you hit the gas pedal?

Whether you have an automatic or manual transmission, such issues are sure to make your drive uncomfortable. 

Luckily, we’ve got some fixes for you!

This article explores three common signs of a jerking car, 13 things that may cause car jerks, its fixes, and related costs

This Article Contains:

Let’s get started.

3 Common Signs Of Transmission Jerks

Here are 3 symptoms that often accompany a jerky transmission:

1. Transmission Fluid Is Dark Or Discolored

Like your engine oil, both automatic and manual transmission fluid also get dirty over time. 

Typically, automatic transmission fluid lasts around 60,000 to 100,000 miles, while manual transmission fluid lasts 30,000 to 60,000 miles. But if it turns dirty or brown quickly, your transmission may undergo some severe wear.

2. Weird Sounds When Changing Gears

Ever wondered what makes the most noise in your transmission?
The answer: The fluid pump.

A fluid pump uses pressure to circulate oil in your car’s valve body. This, in turn, controls the clutches and bands in your planetary gearbox. If the fluid gets low, dirty, or clogged, the fluid pump makes a loud noise when you change the gear.

3. Difficulty In Shifting Gears

If you notice the following three signs while shifting gears, your car may be having a serious transmission issue:

However, if your car has a computer-controlled transmission, erratic gear shifts or any other transmission problem can also happen due to a bad sensor or shift solenoid.

Now, let’s check out some causes behind those car jerks:

13 Reasons Why Your Car’s Transmission Jerks

From a clogged catalytic converter to a worn-out transmission and low transmission fluid, there are many reasons for your car to jerk.

Here are some of the usual reasons:

1. Worn-Out Transmission

Transmission bands and clutches help you change your gears swiftly. But over time, these bands and clutches may smoothen out, making it difficult to hold things together. 

In such cases, it’s best to get an expert to check out the transmission.

2. Old Or Incorrect Transmission Fluid

Your transmission is built with materials compatible with a specific transmission fluid. 

That’s why manufacturers recommend using a certain transmission fluid type to avoid any transmission trouble. Using the wrong transmission fluid may result in some hard car jerks, especially at high speed. 

These aren’t the only transmission fluid issues affecting your car.

If your transmission fluid becomes old, it’ll reduce the fluid’s lubrication and friction-modifying properties — ultimately leading to transmission shifting issues.

3. Low Transmission Fluid

Transmission fluid lubricates and provides the hydraulic pressure needed to move the clutches and bands for the shifts in automatic transmissions.

Low transmission fluid levels may lead to low pressure and result in transmission trouble, like a hard-shifting automatic transmission. So if your transmission fluid level is low, your transmission light may pop on, and it’s best to top it as early as possible.

4. Worn-Out Transmission Oil Filter

With time and use, metal chips may form in some of your transmission parts. It’ll then clog the automatic transmission oil filter and limit the transmission fluid supply. This affects the functioning of friction discs.

As a result, the discs won’t be able to stop at the right time and won’t have the necessary force to slip again. That’s why your car jerks when you press the brake pedal and shift gears.

This is why it’s essential to get regular transmission service and use high-quality ATF oil according to the manufacturer’s instructions.

5. Malfunctioning Torque Converter 

A bad torque converter shows almost the same signs as a slipping gear.

A torque converter connects the engine to the car transmission. You can suspect a torque issue if you notice a slipping transmission. It usually means that your fluid isn’t being managed well.

6. Faulty Friction Plates

The friction plates in automatic transmission vehicles act as a clutch when changing gears. 

You may feel shocks when changing gears if the plates wear out. Besides the jerks, the transmission fluid levels might also drop drastically or lose their properties. If the plates have major wear, these shocks or twitching may intensify. 

And if the plates are beyond repair, your gear may appear too stubborn to shift. 

7. Bad Transmission Oil Cooler

Ideally, a transmission oil cooler should cool the transmission fluid. However, the cooler tends to get hot as its performance decreases because of how old transmission fluid is replaced. 

Here’s the thing:
Oil fluid is generally extracted without replacing the oil filter or flushing the box tray. This brings the dirt from the bottom to rise and clogs other transmission parts like the radiator, hydraulic plate, and solenoids. 

8. Malfunctioning Valve Body

Also known as the hydraulic valve, the valve body has many channels through which the transmission fluid runs under hydraulic pressure to compress or expand the clutches. 

Sometimes, the channels get clogged with dirt, which affects the clutch’s functioning, ultimately leading to car jerks.  

That’s why it’s vital to change the transmission fluid regularly. However, to clean the channels, you’ll have to dismantle the car transmission system, which can be expensive.

9. Flawed Transmission Oil Pump

The transmission oil pump rarely fails unless there are some technical issues. 

If the pump fails, it might be due to issues in transmission fluid circulation. This can result in your car jerking when shifting the gear. In worst-case scenarios, a failed transmission fluid pump could even cause transmission failure. 

10. Cold Weather 

Extreme temperature can affect transmission fluid with low cold-flow properties. Here, the fluid could elongate and can cause hard shifts until the fluid is warm.

To avoid this transmission issue, switch to synthetic fluid. Since synthetics don’t contain wax, the fluid retains fluidity at lower temperatures during cold weather.

11. Blocked Catalytic Converter

A catalytic converter helps regulate the emissions put out by your car. 

So if you have a failing or blocked catalytic converter, air and fuel may mix unevenly. This might cause your car to jerk, especially accelerating at a low speed or pressing the gas pedal. 

12. Scaling On The Brake Discs

Does your car jerk when you shift your car transmission from reverse to drive?
Then it’s likely that your low-quality brake discs are the culprits.

Low-quality brake discs collect scales and sediments that jerk your car when you press the brake pedal.

13. Defective Electronic Control Unit

Sometimes, the Electronic Control Unit (ECU) can malfunction, causing jerks in the automatic transmission. In such cases, the car not only jerks but may cause some other transmission problem.

Note: Some transmission-related issues may trigger the ECU to turn on the check engine light. 

Other causes for transmission jerks:

So how do we fix these issues?

2 Common Fixes For Transmission Jerks

A transmission repair depends on the cause and the severity of the issue. 

For example, if low fluid levels cause a slipping transmission, you must top up the fluid. But if it’s caused by more serious issues like a clogged catalytic converter or a transmission leak, you may need an expert before it becomes an expensive transmission problem.

Here are some common fixes:

1. Low Fluid Level – Check and Top-Off

It’s a good idea to check your transmission level once a month or if you drive a lot — every two weeks. To do so, open the hood, locate the transmission dipstick, and check the transmission fluid level. 

When checking, if you find the fluid dark, thin, dirty, or has a burnt smell, remember to change it immediately. And if the transmission fluid level is dangerously low —  top it up to prevent any potential damage like transmission failure.

2. Burnt Or Worn Out Fluid – Drain & Refill

Since changing the transmission fluid can be messy, it’s best to leave it to an expert.
Nevertheless, here’s a guide on changing transmission fluid:

Next, let’s look at how much these repairs cost.

Transmission Jerks Repair Cost 

Repair costs for transmission jerks may vary according to the diagnosis and local labor charges:

Wrapping Up

It’s no fun to drive with your car jerking whenever you attempt to change your gear or drive at high speed. So the next time you have a jerking car, contact the best mechanics in town — AutoNation Mobile Service!

AutoNation Mobile Service is a mobile car repair and maintenance solution, available seven days a week. We offer upfront pricing, convenient online booking, and a 12-month, 12,000-mile warranty on all repairs.

Get in touch with AutoNation Mobile Service if you’re experiencing any unusual jerks, and we’ll come to you to diagnose the issue.