5 Common Jeep Wrangler Automatic Transmission Shifting Problems

Jeep Wranglers are considered to be among the best SUVs on the car market, but they have been known to experience some automatic transmission shifting problems.

What problems do Jeep Wranglers with automatic transmissions have?

The most common Jeep Wrangler automatic transmission shifting problems are delayed or failed gear changes, delayed or failed gear engagement, gear slips & unpredictable gear changes, unexpected shifts to neutral, as well as torque converter & overdrive issues.

After extensively researching Jeep automotive troubleshooting forums, I have been able to gather enough information to determine the common problems associated with the Wrangler’s automatic transmission. 

My research has indicated that the Jeep Wrangler’s check engine light is not always responsive to transmission issues and that drivers should get their vehicles serviced as soon as symptoms become apparent.

Common Jeep Wrangler Transmission Problems 

Since its launch in 1986, the Jeep Wrangler has earned a reputation as a reliable SUV. Known for its toughness, durability, and ability to tackle rough terrain and harsh conditions, Jeep’s vehicle stands out.

With each new generation, the Wrangler has seen significant updates, including its parts, components, and look changes.

Now, after more than 35 years on the market, the Wrangler is in its fourth generation.

However, the Jeep Wrangler is not without flaws. It is especially known for transmission problems, which are common across many models.

Knowing about these transmission problems can save you a lot of money on future maintenance. Alternatively, this knowledge might lead you to avoid certain Wrangler models.

Delayed or Failed Gear Changes

I noticed that a common problem with a lot of older Jeep models was that the automatic transmission had delayed or failed gear changes. This symptom is particularly problematic with Jeep Wranglers that are built with 42RE or 42RLE 4-speed automatic transmissions.

A delayed or failed gear change can occur in specific situations. Most commonly, Jeep Wrangler drivers would encounter this issue when they were changing gears from 1st to 3rd and when changing from 3rd to 4th.

Identifying the severity of this problem can be challenging for many Jeep Wrangler owners given that it does not trigger a check engine light that encourages you to go get it checked out – with most people thinking it is an isolated incident or due to their own driving.

Delayed or Failed Gear Engagement 

Automatic transmission problems, particularly poor gear engagement, are frequent complaints from Jeep Wrangler owners. They often report delays in gear engagement or complete failure to engage.

This issue is most noticeable in models equipped with the 545RFE 5-speed automatic transmission. Unlike issues related to gears not shifting, gear engagement failures usually trigger the check engine light in Jeep Wranglers.

If the check engine light remains off but gear engagement issues persist, the problem is often more evident in cold weather. Cold temperatures seem to exacerbate engagement problems.

This problem often stems from a loose cooler filter, which allows transmission fluid to leak onto the torque converter. When the vehicle is off, the fluid continues to drain, leading to gear engagement issues upon restarting the vehicle.

In cases without fluid leaks, checking the transmission fluid’s quality is crucial. Old or dirty fluid can cause engagement issues. Using incorrect transmission fluid or a low fluid level also leads to delayed or failed gear engagement.

Gear Slips & Unpredictable Gear Changes

There have been many complaints from Jeep Wrangler owners about their vehicles slipping gears. In addition, unpredictable gear changes that appear erratically are also common with Jeeps that experience these symptoms.

This problem usually starts with occasional gear slips and gets progressively worse over time. I have noticed that Jeep Wranglers with A6MF1 6-speed automatic transmissions are much more likely to develop this issue compared to other models.

The Jeeps that have an A6MF1 6-speed automatic transmission are front-wheel drive SUVs and they will usually experience this when the outside weather is cold. A Wrangler with this specific transmission problem is designed to trigger a check engine light so that the driver knows to get the vehicle serviced. With that said, there have been a number of reports of Jeep Wrangler check engine lights being unresponsive to this.

More often than not, gear slips and unpredictable gear changes are tied to a solenoid issue. If the problem is really bad, then you will need to replace the entire solenoid set. However, you may be able to simply replace the wiring if the set is not damaged. 

Unexpected Shits to Neutral

If your Jeep Wrangler has a ZF9HP48 9-speed automatic transmission, one of the most common problems that can develop is that the vehicle unexpectedly shifts to neutral. This should be a front-wheel drive Wrangler and the most common reason behind it is that the transaxle range sensor connector is damaged or faulty. 

The majority of the time that this problem occurs, it is completely random and will generally happen when the Wrangler is in motion. If your vehicle is functioning properly, a check engine light should appear to indicate that the Jeep needs to be serviced.

Torque Converter & Overdrive Issues

When you encounter a problem with your torque converter, it will inhibit the performance of your entire transmission system, as it is connected to the turbine, clutch, impeller pump, and transmission fluid of your Jeep.

If this is behind the automatic transmission issue, one way that you can identify it is by the gears slipping. In addition, the car may shake and shudder when this transmission problem occurs. Jeep designed the Wranger to trigger a check engine light if there is a torque converter or overdrive problem.

There are a number of different factors that can contribute to this and you ultimately will have to get the vehicle checked out to figure out what is causing the issue. One of the most common reasons behind it is a faulty throttle position sensor.

Key Takeaways 

• Common Jeep Wrangler automatic transmission shifting problems include: delayed or failed gear changes, delayed or failed gear engagement, gear slips & unpredictable gear changes, unexpected shifts to neutral, as well as torque converter & overdrive issues.
• These issues are usually found in 42RE or 42RLE 4-speed, 545RFE 5-speed, A6MF1 6-speed, and ZF9HP48 9-speed Jeep Wrangler automatic transmissions.
• The majority of these transmission issues are designed to trigger a ‘Check Engine Light’ in your Jeep Wrangler, but this feature is not always responsive.