2018-2019 Jeep Wrangler Transmission Problems (Manual & Automatic)

If you own a 2018-2019 Jeep Wrangler and have been experiencing some weird behavior with your transmission, then you should find something interesting here. Wrangler JL owners have reported suspicious behavior causing their wranglers to go into limp mode. Some reports include harsh gear shifting and loss of power, while others report sloppy clutch pedals. Let’s look into it and what the possible causes are.

There nothing more frustrating than having endless reliability issues after recently purchasing a vehicle, may it be new or used. You’re still unfamiliar with the vehicle dynamics and not always sure if certain behavior is “normal” or cause for concern. Sometimes these woes can get so frustrating that you even considered selling the vehicle event though you love the brand. Whatever your situation may be, we’ll look at a few transmission issues 2018 and 19 Jeep Wrangler owners have reported online, which could give you some insight and possibly offer a solution.

Jeep Wrangler Automatic Transmission Problems

I’ve personally experienced the symptoms of a sketchy Jeep transmission when my mate and I were driving in his trusty 2018 Wrangler, feeling all cool and stuff, when suddenly, the CHECK ENGINE –FAULTY TRANSMISSION light appears. OOPS! Not something you want to see right!

All sorts of crazy thoughts immediately starts going through our minds. What did we do?

After a bit of inspection we noticed some transmission fluid dripping from underneath the vehicle. Later we also noticed fluid in his driveway. The vehicle felt rather weird like it was holding onto the gears a bit longer than necessary. And the transmission didn’t sound too healthy either.  Prior to that we noticed the up-shifting was lethargic, even when on a decline, holding the revs at over 2500rpm.

What was the problem?

What we noticed was a leak somewhere near the transmission, hence the oil spill. Also, the transmission fluid was low, so that possibly affected the shifting process somewhat, causing the transmission to labor a bit.

Leaking Seals

If this happens to you, crawl underneath and have a look around the transmission to inspect where the leak is coming from? Later it was discovered by the dealership to be a leaking rear seal, which was sorted under warranty.

Symptoms experienced:

  • Lethargic gear shifting
  • Holding the gear till 2500
  • Oil leaks
  • Check engine – Faulty Transmission light

Harsh Down Shifting

Bear in mind the 8-speed automatic transmission has a learning process, which records your driving style and throttle position over time. So, if you experience harsh down-shifting, like the Jeep is confused when coming to a stop, it should improve over time as the transmission control module adjusts. But it shouldn’t feel violent or aggressive when it downshifts coming to a stop or rolling and pulling off immediately.

The ZF transmission was designed to improve the vehicles fuel economy, and can achieve up to an 11% fuel saving compared to the ZF 6-speed transmission and 14% versus modern 5-speed transmissions. In General the 8speed box is smooth and should shift up effortlessly from pull-off. The 850RE Torqueflite eight-speed automatic transmission is world-known for being one of the more reliable transmissions built.

Gone are the days of crude gear shifts and jerky downshifts, so if you experiencing something similar, something’s amiss.

Fuel Pump

Harsh up and down shifting can often be put down to fuel related. Its sounds weird indeed, however the fuel supply will send signals to the ECU which will control other factors. So, in the case of a bad fuel pump which delivers weak or reduced fuel flow, it will definitely result in a reduction in power. This will cause the transmission to delay shifting to the next gear. The transmission shift points are normally controlled by outside sensors, including fuel supply and pressure. Doing a diagnostics test will more than likely reveal a faulty fuel pump fault code.

2018 Jeep Wrangler Manual Transmission Problems

If you have a 2018 Manual Jeep Wrangler and the vehicle feels underpowered and goes into limp mode it could be any of the following:

  • Fuel Pump
  • Fuel Relay
  • A clog in the fuel line
  • Faulty PCM control module

However, sometimes you get these weird issues, not only with jeeps but all modern diesels and it’s hard to trace without a diagnostics machine or with DIY inspections. It could be something completely unrelated, like an electrical gremlin. One owner reports that after the dealership replaced almost all his fuel system components the vehicle still went into limp mode. It was eventually traced to an electrical fault and a lose pin in a wiring harness.

So what are some symptoms you can look out for?

Symptoms

  • Vehicle goes into Limp Mode
  • start stop light goes on
  • Underpowered between gears switching
  • Sluggish behavior
  • engine vibration and shaking

Solution

Lose pin in the harness

Park Rod Recall

Early in 2018 there was a recall to replace transmission park rods on approximately 71 units.

NHTSA warned, “If the incorrect park lock rod is installed, the transmission may not shift into ‘PARK’ and keep the vehicle from moving, increasing the risk of unintended vehicle movement and the risk of crash.”

Clutch Pressure Plate May Overheat

The overheated clutch components may increase the risk of a fire. Additionally, damage to other nearby components can result in debris falling onto the road or a loss of drive, increasing the risk of a crash.

NHTSA Campaign Number: 20V124000

Manufacturer: Chrysler (FCA US LLC)

Components: POWER TRAIN

Potential Number of Units Affected: 33,237

Summary:

Chrysler (FCA US LLC) is recalling certain 2018-2020 Jeep Wrangler and 2020 Gladiator vehicles equipped with manual transmissions. The clutch pressure plate may overheat and fracture.

Remedy

The remedy for this recall is still under development. The recall is expected to begin April 22, 2020. Owners may contact Chrysler customer service at 1-800-853-1403. Chrysler’s number for this recall is W12.

Notes

Owners may also contact the National Highway Traffic Safety Administration Vehicle Safety Hotline at 1-888-327-4236 (TTY 1-800-424-9153), or go to www.safercar.gov.

2019 Jeep Wrangler Transmission Problems

Jeep wrangler owners are generally very happy owners, since their vehicles don’t give them too much drama, and the drama it does give, they are generally happy to deal with as a small price to pay. However there are a few complaints from 2019 Wrangler owners.

Remember, these are not recalled or what you can really call “common” occurrences, just reports of faults owners have experienced with 2019 models.

Remember, people seldom take the time to compliment a vehicle for doing what it’s meant to, however when there is a problem, the first thing they’ll do is hop online and lodge a complaint. This could give you the impression the problem is worse than it actually is and could just be a few isolated cases or part of a batch that had a recall. It’s still good to be aware, since these can happen to you at a later stage and the owners input can assist you to diagnose the problem faster.

Without any further delay, let’s look at some reports of transmission issues only.

  1. Odd engine noises
  2. Fluid all over the undercarriage. (Leaking rear seal)
  3. Transmission noises when shifting from park to drive or reverse
  4. Clunking noise especially on a cold start up
  5. Issues with the start stop or the transmission
  6. Power losses (Fuel related)
  7. Loose Clutch pedal (recall)
  8. Sluggish performance
  9. Shakes and vibrates excessively

It’s important to isolate transmission issues with stop/start issues. If you experience any weird behavior with the stop/start activated, disable it and see if the problem persists. If it does, you know its transmission related.

If the Jeep feels like it is about to die, it could be related to the charging system, fuel system or a weak battery. Usually with fuel related issues, it’s not intermittent. Do all the basic checks like battery terminal, earth ground strap, battery health and underneath for anything obvious first.

2019 jeep wrangler start stop disable

SmartStopStart module is a memory device for the ESS disable button

The module installs easily under the dash, and does not disable the Security Gateway Module (SGW) nor does it take up the OBDII port. It also does not set off any fault lights, warning dings or fault codes. Check out the

The module makes no modifications to the OEM software in the vehicle at all. It also does not cause any faults. If it is removed, there is no evidence that it has been used as long as you plug the cable back into it its original socket.

Alternatively, you can do it the manual way and remove the start stop plug in the engine bay like this:

https://youtu.be/AxFZYzKbSJo

Resources

Wrangler transmission Filter

Transmission Mount

Transmission Oil cooler Line

Mopar Transmission Fluid

RIPP Superchargers JK Wrangler Automatic Transmission Cooler – 0714TRANS

Jeep Transmission Shifter – 52060064AG

Transmission Input Speed Sensor

Crown Automotive Transmission Output Seal – J8134680

Crown Automotive Transmission Case Gasket – 2466954

Conclusion

If your jeep is giving you endless transmission issues, keep a record of the issues you are experiencing and what you were doing at the time. Your best bet is to figure out how to reproduce it so you can explain and demonstrate to your dealership.

Jade C.

4-Wheel drives and off-road driving techniques has been my passion for over 20 years. Here we strive to provide the most accurate, up-to-date, information about the functionality, common faults and latest technology built into most 4 Wheel Drives.

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