Whenever our cars have problems, it’s typically something that prevents them from going forward. Yet, some issues can also prevent your automatic car from going backwards. So, if you have a car struggling to reverse, you’ve come to the right place.

Here are 5 most likely reasons why your car won’t go in reverse:

• Low or contaminated transmission fluid
• Clogged or dirty filter
• Faulty transmission position sensor
• Worn-out valve body
• Damaged reverse gear

Depending on how severe the problem is, you can repair, rebuild, or replace your transmission.

Transmission problems of any kind can be pretty tricky, but we’ll help you sort out the issue.

Let’s get started.

5 Reasons Why Your Car Won’t Go in Reverse

Firstly, if your car won’t go in reverse, it’s likely a problem with the transmission. If that’s the case, you may also notice one or more of these faulty transmission symptoms. 

Aside from a bad transmission, there are other reasons why your car won’t go in reverse. Here are 5 of the most common culprit.

#1 Low Transmission Fluid

When troubleshooting transmission problems, always begin with the potential causes that are quicker to rule out. By taking this approach, you will save time and money.

So, first and foremost, check that you have enough transmission fluid.

Low transmission fluid can cause a long list of problems, and one is that you can’t get your car to go into reverse. 

Transmission fluid isn’t the kind that gets consumed or burns up by itself, so what causes it to get depleted?

Two most likely reasons you don’t have enough transmission fluid are:

• You didn’t pour in enough fluid during your last transmission fluid change.
• Fluid has been leaking from your car.

As you check your transmission fluid levels, be sure to peek underneath where your car is usually parked. If you see a dark orange or reddish-brown puddle, you likely have a transmission leak on your hands.

#2 Dirty Transmission Fluid or Clogged Filter

Having enough transmission fluid isn’t the only thing that matters. That fluid must also be clean, and so must be the filter that removes impurities from it.

When transmission problems happen (like failing to go in reverse), but there is enough fluid, it’s time to check the cleanliness of what’s already inside the transmission.

Dirty transmission fluid will have water, debris, or other impurities that prevent the transmission from working smoothly. Besides that, a dirty filter will get clogged and prevent the fluid from flowing to where it’s needed.

#3 Faulty Transmission Position Sensor

Many cars these days have a transmission position sensor (aka the transmission range sensor) inside them. The sensor checks the transmission’s position and sends that information to the Powertrain Control Module (PCM), which controls it.

When the sensor gets faulty, the PCM can’t figure out what gear the transmission is in. As a result, the reverse gear won’t activate even when you move the gear handle to Reverse (R).

#4 Worn Out Valve Body

One of the most critical parts of your automatic transmission is the valve body. Visually, the valve body looks like a series of complicated maze for the transmission fluid to flow through. However, when it works correctly, the fluid will flow to where it’s needed and trigger the correct clutch pack necessary to switch your car into reverse.

The valve body also depends on several moving parts in the transmission. Unfortunately, those parts can wear out and cause problems like metal parts rubbing against each other and releasing metal pieces into the transmission fluid.

As we’ve seen in #2, dirty or contaminated transmission fluid can prevent your car from going into reverse and clog up the filter as well.

Besides that, a worn-out valve body can also prevent the correct clutch pack from engaging, which will also make it impossible for your car to back up.

#5 Reverse Gear Failure

Last but not least, the problem could be that the reverse gear itself has suffered a failure. Such a failure can be caused by:

• Not enough lubrication - a lack of lubrication between moving metal parts is terrible news. That will cause metal parts to rub against each other and create friction, leading to damage and excess heat.
• Contamination - As we saw earlier, contaminated lubricant or fluids can also cause damage to the reverse gear itself.
• Wrong installation - Although less likely, you might have installed the reverse gear wrongly after something like a transmission rebuild.
• Overloading - Also less likely, but still possible. The reverse gear might have been overloaded somehow to the point that it gets damaged and won’t work correctly anymore.

What to Do When Your Car Doesn’t Go in Reverse

When it comes to transmission problems, you have three options:

• Repair
• Rebuild
• Replace

The ideal solution will depend on the root cause. 

Transmission Repair

For example, if your car won’t reverse because it’s leaking transmission fluid, all you must do is get the leaking part repaired. The same is true with more severe cases, like a damaged reverse gear.

Transmission Rebuild

However, a moderately problematic transmission might require a rebuild, which involves taking the transmission apart and then checking and cleaning each part. As you can imagine, this one involves many more hours of labour, which also means a higher cost.

On the plus side, the reversing problem isn’t the only one that’ll get attention. Instead, your whole transmission will be diagnosed, cleaned, and repaired (if needed). You’ll have much more peace of mind afterwards.

Transmission Replacement

Of course, if the failed reverse gear is only one part of a transmission that’s in terrible shape, you might want to consider replacing the whole thing.

Depending on the extent of the damage, a replacement could be a more straightforward solution.

Sure, a brand-new transmission is pricey, but you can reduce costs by purchasing a used one in excellent condition.

(Blog from carpart.com.au)