The iconic Jeep Wrangler JK model has not gone without its fair share of transmission shifting problems over the past several years. Over many years, Jeep owners have had to deal with transmission issues, some of which were so severe that they resulted in recalls. Although a Jeep’s transmission is designed to last between 120,000 and 180,000 miles before changing, transmission issues occur based on your Wrangler’s year. If you notice shifting problems, it’s important to have the transmission inspected immediately, or else your off-roading fun is going to come to an end quickly.
To learn more about some of the most common shifting problems and solutions, keep reading!
Failed Gear Engagement
A failed gear engagement is most common in the 545RFE five-speed transmission, https://reman-transmission.com/transmission-codes/?code=545RFE. With this issue, the gears fail to engage when placing your Jeep in reverse or drive. This occurs when the vehicle is cold and is most likely to be problematic in cold temperatures. This problem can also be caused by using the wrong transmission fluid type, or low or dirty transmission fluid. Another cause could be a loose transmission cooler. When this occurs, the fluid drains from the torque converter. When starting the vehicle, pressure must build before the transmission functions properly, so if the fluid is drained, the gears won’t engage.
Delayed Shifting
Delayed shifting is a common issue with 42RE and 42RE four-speed transmissions. This problem will arise when shifting from first to third, or third to fourth gears. Delayed shifting can be incredibly frustrating and have a significant impact on the Wrangler’s performance, especially when off-roading. When this occurs, an engine warning light will not come on, unless there are other associated problems.
Several potential causes exist, including dirty or low transmission fluid. This is the easiest to fix by replacing the transmission fluid. Another cause is a stuck or worn pressure solenoid that can limit the transmission from maintaining proper fluid pressure, which is especially required when shifting from first to third.
Another problem is worn bands, which can cause shifting delays, shifting to occur at high RPMs, no gear engagement, no reverse, or harsh shifting. If your bands are worn, then they must be replaced to get your transmission back in proper working order. An additional issue is a sensor failure or faulty wiring, both of which need to be replaced or corrected to resolve the issue. If this problem occurs when the fourth gear is engaged, then your most probable challenge is the overdrive solenoid, which will need to be replaced.
Torque Converter/Overdrive Issues
Torque converter and overdrive problems are most common in the 42RE, 42RE four-speed, and 42RLE transmission found in the Wrangler model years 2000 and later. https://reman-transmission.com/transmission-codes/?code=42RLE. The issue is typically intermittent, which causes the check engine light to shine. The best method of determining the root cause is to check it with a code reader. These transmissions often suffer from broken cover plates, which will trigger the P1740 code. If you determine this to be the issue, upgrade kits exist which will repair the problem.
The other most probable cause is faulty sensors. The throttle body and input/output sensor failure resulted in the torque converter clutch not properly engaging. If this is determined to be the root cause, then you must replace the faulty sensor to ensure proper engagement.
If you currently own or are considering purchasing a Jeep Wrangler, they are excellent vehicles and leaders in off-roading, but transmission issues are common, which you need to be prepared to deal with. Although most of these issues have simple remedies, like making a few mechanical updates or changing the transmission fluid, you may need to dig deeper in your pockets to resolve the larger and more detailed issues.