Help?! 2020 JLU Fishtailed and Rolled From Potential Clutch and ABS System Failure

[Willing&Able]

Are you suppose to shift from 2H to 4H while driving at 'normal' speeds? I've only done it from a stop and give it just enough gas to roll it forward and then shift. Seems to be the easiest way to engage the transfer case.

This is my first 4x4 - so asking to educate myself as well...

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[JDJeep85]

At least you could drive it away

Wow...

Could you post a photo of the drivers side of the Jeep now?

Sure, I'll add one tomorrow once it's light out. There was very little visible damage, you can almost not tell honestly other than the missing mirror (which I clipped off b/c of it dangling after being crushed) and some minor dents to the fenders and scrapes along the rain gutter. Almost no paint scratches, but the hood looks slightly out of shape on the drivers side. I think this is also due to how slow I was moving when it rolled, since it did not skid at all in the process really.

 

[JDJeep85]

Are you suppose to shift from 2H to 4H while driving at 'normal' speeds? I've only done it from a stop and give it just enough gas to roll it forward and then shift. Seems to be the easiest way to engage the transfer case.

This is my first 4x4 - so asking to educate myself as well...

Yes, based on the manual and my understanding is that 4WD (High) can be engaged at speeds up to 55MPH. 4WD Low however is MUCH different, you need to be in neutral when transitioning in and out and and be rolling/moving very slowly (<25 MPH) you need to take care not to shift too quickly while you're doing it.

 

[JDJeep85]

Yes, based on the manual and my understanding is that 4WD (High) can be engaged at speeds up to 55MPH. 4WD Low however is MUCH different, you need to be in neutral when transitioning in and out and and be rolling/moving very slowly (<25 MPH) you need to take care not to shift too quickly while you're doing it.

 

[JDJeep85]

I believe you about the codes. Welcome to the glitchy JL electrical world. My electrical systems is totally unreliable (2020 JLUR 5k miles ). I have had a number of on road dangerous power losses and system issues while driving, all would have been worst had I been driving were you were.

Jeep is of no help with electrical issues and doesn’t know how to fix them. I bet your computer glitched as you were switching from 4HI and caused other systems to act incorrectly.

Glade you are safe and walked away only shaken and not physically hurt.

EEshh ok, thanks for the heads up. I feel super lucky no one was hurt, I was SUPER stressed and worried that someone else might get hurt when they were trying to help me (since I was alone) :/ The driver behind me was extremely cool and helped me for like an hour <3

 

[ErAcEr]

Jeep roll-over. Go to 1:44

 

[sf5211]

No offense but this is another reason why I like the good old fashioned manual transmission. Step on that left pedal and the drivetrain is disengaged.

 

[Black Jeep Convertible]

Did you let off the gas before shifting into 4hi?

 

[roaniecowpony]

Depending on how you want this to go down, you might consider hiring a professional accident investigator or even a product liability attorney, before you take the Jeep into a dealer. If you take it to the dealer, they will likely clear all the recorded accident data, if any still exists. Also, your insurance may likely attribute the accident to you and raise your rates. Something to think about.

 

[Creeker]

It is possible that the codes that were cleared by the dealer are a clue to what happened.


Since the JL started to fish tail, it seems that the rear could have locked up. Either mechanically (gearing) or ABS.

The crash down load from the JL's computer may give clues to this incident. Some of the history may be cleared each time the ignition switch is turned ON/OFF. Recommended getting the codes read as soon as possible. The company I work for does a bunch of accident reconstruction and this is some of what has been learned from the folks who do this studies.

IMHO, it is recommended to all that folks do not shift from 2H to 4H while traveling more than a crawl speed until the root cause of this incident is determined.

 

[The Last Cowboy]

I’ve shifted all of my 4x4s, including my current Jeep, into 4hi at speeds up to 60 MPH. I’ve never had an issue.

You will want those codes from the airbag control module. That is where the crash event codes are stored. Since you said it happened at a near stop, it may not have triggered an event.

 

[DanW]

Did you test out the 4wd after the dealer gave it back to you? The concerning thing to me is the noise when you got the codes the first time. But then again, transfer cases are noisy. But I'd love to know their test drive protocol. Sounds like they just didn't look very hard at it.

The stiffness of the shifter is normal in the JL. Every one I know with a JL has said something about that. Mine is 3 years old and has been in and out of 4wd many many times and while it has eased up a bit, it is still very stiff compared to my JK.

Did you get any pics of the skid marks in the snow leading up to where it rolled?

I'm really sorry to see that happen to you. It is good though that you are fine and it didn't cause more damage.

 

[Nomad]

This is my first Jeep but I've owned many four wheel drives with every type of engagement system from auto trans/pushbutton 4wd to manual trans/manual locking hubs. The first time I shifted this JL into 4wd I had already heard how stiff it can be so I did it as a warm-weather test in my gravel work parking lot, going 2mph. It was so stiff just trying to get the lever to move at all, when I gave it a strong enough jerk it went right past High and into Low. Was the lever indeed in high after everything came to a stop, and not low? Suddenly dropping the gearing that low on a slippery surface, even at low speeds, could break traction at all four wheels simultaneously, and though it was the back end that swung around you might not have had any traction in the front either. Just a thought.

No injuries is the important thing. Stuff can be fixed. Glad you're okay.

 

[Karnak]

Yes, based on the manual and my understanding is that 4WD (High) can be engaged at speeds up to 55MPH. 4WD Low however is MUCH different, you need to be in neutral when transitioning in and out and and be rolling/moving very slowly (<25 MPH) you need to take care not to shift too quickly while you're doing it.

I'll add that as an added safety, even in 4wd high, ideally, you should be in neutral when shifting from 2wd to 4wd high so that your driveline has time to adjust easily. This will also help you a lot in regards to your stiff lever because it releives the pressure from the driveline which enables much smoother transition and shift lever movement.

in your case for your crash (i'm no expert, keep that in mind), it is possible that the pressure on the driveline (still in gear, still gas pedal or braking, etc ) created a "jolt" in the rear diff when the 4wd clicked in and this jolted the tires just enough to remove their traction since those muds without sipes are good in deep snow, but cannot evacuate the water correctly because of the absence of the micro siping in them and they could have lost the traction just enough to slip and because you have a willis (with the LSD) then it means both tires would go out from under (fishtail) if the slip is "forced" by a jolt from the vehicle (similar to trying to burnout) and then you know the rest.

I think in your case it was a combination of all the right factors where there at the same time and all it needed was a tiny push to activate the chain reaction which the "jolt" could have been it, but I'm not expert althought I had a lot of jeeps and real mecanical 4x4's.

One thing to also note is that Jeep 4x4's are not like the all wheel drive found on many cars today, they're mecanical and not somekind of liquid transfer pressure system and as such, when they engage, they do (clunk or jolt a bit)...if there is pressure on the driveline, they will clunk and sometimes jolt back (sometimes hard), its the nature of the beast, works awesome off-road tough but thats why everything you can do to eliminate the jolt as much as possible it important, including putting it in neutral and letting off the gas...:D

it could have also been your transfer case not engaging fully (hard lever) and then it kicked your back LSD enough to loose your rear (like stated before) and when it was fishtailing, you probably didn't have time to verify it was correctly engaged and by the time it was on its side, it now probably was...

sorry for your mishap, but at least your ok, no one was hurt and your jeep is not banged up too much.

if you go through your inssurance, you can ask them to take a look at the computer readout and they can determine what went wrong and if its a part failing etc.

 

[Jeepadoodle]

Glad you are ok.

Mine is very hard to shift into 4H as well. Had many 4wd in my lifetime and this one is the hardest I can recall. Shifting back to 2wd is normal though. Hope they figure it out for you.

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