JLUR decelerating while coasting in **2H**... help?

[DGD]

Hi all. I’ve had three automatic JK/Us and I drive countless rental vehicles each year. I just purchased my 2019 factory build JLUR three weeks ago. Shortly after leaving the lot, I noticed the brakes felt a little bit sticky and grabby (technical mechanic terms ) at under 20 mph coming to a stop. Shortly later, I realized that the vehicle seems to decelerate even when coasting at that speed without touching the brake pedal. It kind of feels like when cruise control slows you down when you’re a few mph over the designated speed, or like driving with two feet where the left foot is always gently and inconsistently riding the brake. It’s subtle, but it’s constant and I’ve never experienced it with any other Wrangler or rental.

I’ve searched the forums and found nothing. But I don’t even know what terms to search for. I’m hoping my fellow Jeepers can guide me a bit so I don’t sound like a lunatic when I consult with my dealership. This is not a Jeep thing. I’ve been in Jeep things since 2010 (1992 if you count a CJ7 manual). This is a my brand new JLUR thing.

Any ideas? Thanks in advance for your guidance!

I have had the same issue, feels like I am braking constantly. Mine is a 2019 JL UL with 8000 miles. When I go down hill from my house I loose speed if I do not keep my foot on the gas; however, in neutral I gain speed on the same downhill. Seems to be getting worse. Did you ever determine what the problem is? I am taking it to the dealer this week. Thanks.

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[BernJLUR]

I have had the same issue, feels like I am braking constantly. Mine is a 2019 JL UL with 8000 miles. When I go down hill from my house I loose speed if I do not keep my foot on the gas; however, in neutral I gain speed on the same downhill. Seems to be getting worse. Did you ever determine what the problem is? I am taking it to the dealer this week. Thanks.

Read through this thread. Some of the later posters say the new automatic is designed this way, to downshift and use the engine to brake when decelerating (similar to downshifting in a manual). At least I hope they're right! Mine hasn't gotten worse or better. I think I'm just getting used to it.

 

[BernJLUR]

I have had the same issue, feels like I am braking constantly. Mine is a 2019 JL UL with 8000 miles. When I go down hill from my house I loose speed if I do not keep my foot on the gas; however, in neutral I gain speed on the same downhill. Seems to be getting worse. Did you ever determine what the problem is? I am taking it to the dealer this week. Thanks.

Let me know if the dealer says or does anything!

 

[JeepCares]

I have had the same issue, feels like I am braking constantly. Mine is a 2019 JL UL with 8000 miles. When I go down hill from my house I loose speed if I do not keep my foot on the gas; however, in neutral I gain speed on the same downhill. Seems to be getting worse. Did you ever determine what the problem is? I am taking it to the dealer this week. Thanks.

Hi DGD,

Sorry to hear you are experiencing this concern with your Wrangler as well. If you’d like an additional layer of assistance as you work with your dealer, please do not hesitate to send us a private message. We would be happy to escalate a case on your behalf so your concerns are formally documented and so we may connect you with a Case Specialist who can work alongside your dealer to find a potential solution.

Mark
Jeep Social Care Specialist

 

[mikebost]

In got the same shifting. It is a normal condition with this transmission. Low speeds, it will downshift and feels like it's holding the vehicle back. I'm still in the auto repair business, every one I've driven does this....JL models
(8 speed transmission , common with 4.10 gears etc....) I assume that you have a Rubicon or Moab with the higher gets gear ratio?

off topic but related

is it ok to shift to neutral ( just to confirm NOT the one between 4H and 4L) while coasting down hill, a lot of times I can coast for a good 1+ Minute and when I did same round trip without coasting my mpg dropped down to 18-19 vs 23-24 using same fuel and about the same average speed and acceleration.

I understand disadvantage on a slippery road but at 65+F with clear road, any disadvantages or may be possible future premature mechanical transmission drivetrain issues ?

 

[Tellurian]

How far are we talking until you come to a complete stop if traveling at 20mph and coasting: 10', 50', more? Do you get the same deceleration when coasting in Drive or Neutral?

 

[mikebost]

How far are we talking until you come to a complete stop if traveling at 20mph and coasting: 10', 50', more? Do you get the same deceleration when coasting in Drive or Neutral?

lets say I’m driving around 50mph and at some point I’m on top of the hill and switching to neutral at this point and continue coasting down hill at 55-65Mph for 1+ minute and when I’m again at uphill and my speed dropping to 40+ I will engage D and just keep going until I will get to another downhill,
I have a stretch of the road on a way back home that I can probably do 50% in coasting mode only

 

[Tiderian]

I'm late to this party, but I'd been wondering about the same thing so I'm glad to see it's not just me. This behavior was one of the first things I noticed about my JL, and for the first few days I thought I had some sort of hill-descent engine braking mode turned on or something.

I eventually decided that it must just be how the 8-speed works; it seems to be pretty aggressive in keeping the RPMs where it wants them.

Before this JL, I drove an '02 Silverado for 18 years and I had pretty good muscle memory for driving in my home area (a little gas here, coast down this hill, a little gas coming out of this curve, etc.) Since getting the Jeep, I've pretty much had to learn to drive all over bc it just acts so different with how it coasts (or doesn't.)

 

[Jehovasfitness]

I think your issue is two fold. First could be the steep gearing of the 8 speed auto and 4.10’s. Secondly, it’s possible that you are having the surging idle issue which is extremely noticeable during deceleration at those speeds. There is a TSB that addresses the surging as well as the noisy cooling fan. Have you noticed an abnormally loud engine cooling fan noise while at idle with the AC turned all the way to its coldest and highest fan speed setting?

I assumed the surging idle was it going into a lower gear. I usually notice this when going downhill, kind of nice actually

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