reason why transmission will not shift into overdrive

3 Reasons Why Transmission Will Not Shift Into Overdrive!

A very common problem with moderately used cars is sometimes the transmission will not shift to overdrive. Now we car drivers know how important overdrive transmission is. So, it’s normal to worry about it if it’s not working. 

So what are the reasons why transmission will not shift into overdrive?

There are mainly three reasons why the transmission will not shift to overdrive. When there is a faulty overdrive button or solenoid, a problem with the transmission fluid or filter problem, or a faulty torque converter. Replacing the faulty compartments can solve these issues. 

But don’t worry we will not leave you hanging. We have discussed these problems as well as their solution in this article. So stick with us till the end. It will be worth your while. 

Why Transmission Will Not Shift Into Overdrive: 3 Reasons & Solutions

There are quite a few reasons why the transmission will not shift to overdrive. Here are the most common reasons why transmission will not shift to overdrive. And yes we’ve addressed the solutions too. 

Reason 1: Faulty Overdrive Button or Solenoid

There is a good chance your overdrive button or the solenoid is not working correctly. This is the most common reason why transmission does not shift override. 

Wear and strain or harm from outside sources can cause the overdrive switch to malfunction. The button may misfire or fail as a result of an internal switch or solenoid components wearing out over time. 

Moreover, wiring issues or exposure to too much heat can harm it. Sometimes, the car won’t start due to overheating.

Solution: Replace the Overdrive Button or Solenoid

If the overdrive button is damaged, it’s best to replace it. And yes, you can do it yourself. Here’s what you should do. 

Step 1: Locate the Overdrive Button or Solenoid

The location of the overdrive switch depends on the model of the car. Hence, for easier understanding, take your car’s owner’s manual. You should be able to find it there. 

However, the general instruction is to look for the gearbox. Because the button is usually located near it. It could be at the front or the rear side of the car. 

You can also trace the electrical connectors that connect to the gearbox. One of these wires connects to the overdrive button. 

Step 2: Disconnect the Electrical Connector

Once you’ve detected the exact electrical connection you need to disconnect it from the solenoid. To do that you need to look for the latch that is holding the connection. It could be located at the head or the bottom side of the connector.

To pull the connector out you need to apply pressure to the latch. You could use your fingers for it or a flathead screwdriver. This should disconnect the connector from the solenoid. 

If the connection is stubborn to disconnect then try wiggling the connector while tugging on it. Avoid pulling too firmly as this could harm the connection or cabling.

Step 3: Remove and Replace the Switch

After you’ve disconnected the wiring, you should be able to take out the switch. Gently, take out the switch from the gearbox. Make sure to do that without damaging any wiring. 

Then, simply attach a new switch to replace the old one. After replacing the switch, all you need to do is reconnect the electrical connectors. 

And this should do the trick. Now, you can check if the transmission shifts to overdrive. 

Reason 2: Transmission Fluid & Filter Problem

With continuous usage, transmission oil degrades and can pick up contaminants, and impurities. This could result in the fluid’s ability to lubricate the gearbox parts. Which might cause damage.

Another reason could be the low fluid levels. The low fluid levels could cause the transmission to act up. And not switch to overdrive. Because low transmission fluid can cause damage.

Solution: Change the Transmission Fluid & Filter

You can fix your shifting problem by just changing the transmission fluid and the filter. However, it could get confusing if you don’t know what you’re doing. 

So, here’s how you can do it. 

Step 1: Prep the Car

First and foremost you must ensure the car engine is cool. You don’t want to damage your car or yourself. 

You also need to make sure the ground is level. 

Step 2: Check the Fluid Level

To check the fluid level you need to locate the fluid dipstick first. The location of the transmission fluid dipstick could vary depending on the model. 

Don’t worry, you don’t need to contact a mechanic for it. Just finding the owner’s manual should do the trick. 

Step 3: Take Out the Filter

At the bottom of the transmission, you’ll find a transmission pan. Once you’ve located it, then comes the tricky part. 

Before you move any further, make sure to place a draining pan under the transmission pan. This will help catch any spill. 

Now, you have to open the transmission pan. To do that first you need to unscrew the bolts. The bolts may vary from model to model. So get a socket wrench that fits. Carefully unscrew the bolts. Make sure to not lose track of your bolts.

Take Out the Filter

Once you’ve unscrewed the transmission pan, slowly try to lower it and put it aside for now. After that, you can see the transmission filter. The filter might be mounted to the transmission’s base or placed inside the pan.

Now, you can see two things depending on the model of your car. You could either take out the filter simply by pulling it. Or, the filter might be bolted. In the case of the latter, you just need to unscrew the bolts. 

Once you have the filter check for any damages. 

Step 4: Replace the Damaged Filter and Fill the Fluid

If your filter seems damaged then the best thing to do is to get a new one. Find a suitable replacement and replace the old one with the new one.

Keep in mind to not overtighten the bolts. Because overtighten bolts are hard to remove like removing the overtightened oil plug.

Once you have the new filter in place, you need to fill the transmission fluid. Fill the recommended amount of fluid in the transmission for your car and you’re all set.

Step 5: Check if the Transmission Shifts

Now, all there is left for you to do is check if it worked. Start your car and try shifting the transmission to overdrive. 

A filter change and fluid refill should do the trick for you.

Here’s a guide on how to change the transmission fluid and filter:

Reason 3: Faulty Torque Converter

Torque converters increase power at fewer revolutions per minute when operating optimally.

Torque converters directly affect the transmission shifting to overdrive. So, if the torque converter is faulty then the transmission will not shift to overdrive. 

If the torque converter is malfunctioning, the drive is rough, and the car jerks when releasing acceleration

Here’s how you can solve this problem.

Solution: Replace the Torque Converter

Replacing a torque converter could be a little complex. It’s always suggested to consult a mechanic for it. However, you can do it yourself too. 

While repairing the torque converter is possible but it’s always recommended to replace it because a torque converter should always be in crisp condition. Even if you repair a damaged torque converter, it’ll not yield the best performance. 

You can find many torque converters online but they are on the costlier side. Make sure to not buy any remastered or used torque converters. 

Here’s how you can replace a torque converter. 

Step 1: Take Out the Transmission

The first thing you need to do is take out the transmission system. The job seems mammoth but it gets easier if you know how to remove the transmission.

Your automobile manual will have the procedure on how to remove the transmission of your vehicle. It can be different for different brands and models. Once you’ve removed the transmission you can move on to the next step.

Step 2: Take Out the Torque Converter

After you’ve taken out the transmission you’ll find the torque converter inside the transmission unit.

Take Out the Torque Converter

Taking out the torque converter is not that difficult. You just need to slide the torque converter from the torque shaft. Then if you just pull it gently it should come right out. 

Step 3: Replace the Torque Converter

Get a new torque converter from a trusted seller. Once the old torque converter is out you can throw in the new one. 

Then all you need to do is put the torque converter in place of the old one. Just slide in the converter through the converter shaft and you’re done. Then finally reassemble the transmission unit in the car. And you should be all set. 

Then you should test if the transmission is shifting to overdrive. 

Frequently Asked Questions (FAQs):

Can you drive without overdrive?

Yes, you can drive without overdrive, however, it is not economical at high speeds. You’ll have no negative impact on the gearbox. But you’ll have worse fuel efficiency. Especially at high speed. Besides, unless there is a steep slope to climb up or down you can leave it on.

Does overdrive use more fuel?

No, overdrive does not use more fuel. Instead, it’s a more fuel-efficient way to go. The engine’s speed reduces when you apply overdrive gearing. Which lowers motor wear and saves fuel. As a result for better fuel efficiency, it is recommended to use the overdrive feature. 

Are overdrive and cruise control the same?

No overdrive and cruise control are not the same. Overdrive is generally used for high-speed driving on highways. It is the highest gear where the fuel consumption is economical. On the other hand cruise control is a feature that allows the car to maintain a constant speed. 


So, now you should know the reasons why transmission will not shift to overdrive. And you can solve it yourself. 

Do not forget to consult a mechanic if you’re stuck at any point. 

That will be all from us. See you another time.

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