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

[hybrid3.0]

How fast were you moving when you did your shift into 4wd HI? You have a Willys which comes standard with LSD so I think you locked the rear axle (like posted earlier) which caused loss of vehicle control. Let's assume a properly functioning transfer case, which may not be a good assumption considering your earlier discussion. When you shifted 'on-the-fly' from 2 HI to 4 HI, the transfer case locks both front and rear drive shafts and immediately attempts to spin the front driveline, which has been disengaged, to match the speed of the rear driveline at your current road speed. The inertial mass of your front driveline components being spun up to speed causes an abrupt counter force applied through the driveline to the rear axle which slowed both rear tires enough to "lock up" and lose traction and the jeep having a high center of gravity hit a snow bank or dropped off the shoulder and rolled.

It might be advisable in the future to slow to 5 mph or less, even coming to a complete stop at some safe location, to make any drive mode changes especially in ice and snow to avoid loss of vehicular control. I am glad you and the jeep are OK and hopefully this won't happen again. If your transfer case is having issues, this needs to get fixed immediately.

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[Wabujitsu]

I would never shift on the fly into 4WD on a slick surface like that, at speed. I know lots of people get away with it, but it still is not advisable, per the last post above.

Another factor that may be in play is this. When traction control and LSD kick in, it is intuitive to counter-steer, which is the LAST thing you want to do when traction control is doing its thing during a skid. It counters for you. Corrective steering can make one lose control of the vehicle when traction control is working.

 

[JEEPIDON]

Let's see if @JeepCares holds this dealer accountable. Jeep needs to have a periodic audit of all dealers, technician training and certification program. Most of these dealer owners don't care about anything but money. Vehicles aren't their passion, just a revenue stream.

JeepCares wasn't created to "hold them accountable". I'm not sure why everyone always shits all over dealers when none of the observers here have the whole story.

 

[JEEPIDON]

I would never shift on the fly into 4WD on a slick surface like that, at speed. I know lots of people get away with it, but it still is not advisable, per the last post above.

Another factor that may be in play is this. When traction control and LSD kick in, it is intuitive to counter-steer, which is the LAST thing you want to do when traction control is doing its thing during a skid. It counters for you. Corrective steering can make one lose control of the vehicle when traction control is working.

Finally some common sense! Shifting at unsafe speeds (determined by the road condition) is never advisable. I've down shifted in my old muscle mopars on rainy roads and have fish tailed all over the place. Slippery conditions warrant more brain cells working and slowing down before drive train configuration changes.

 

[coldstart]

JeepCares wasn't created to "hold them accountable". I'm not sure why everyone always shits all over dealers when none of the observers here have the whole story.

You must own or work for a dealer because they’re all shit. That’s why people shit on them back.

 

[higbyz]

You must own or work for a dealer because they’re all shit. That’s why people shit on them back.

Goss Jeep in Burlington Vt has an awesome service dept. The sales dept,meh !

 

[hybrid3.0]

I had a '79 Z28 that had racing transmission shift kit so that it would slam into gear for quick upshifts. Pulling a gradual left turn away from a stoplight after soaking the rear tires in the sudsy overflow of a corner car wash was enough to spin me out onto a curb when second gear hit and I broke a wheel. My dad still to this day believes I was racing when he came to help me get the car back on the road with a spare tire!

 

[Strommen95]

You must own or work for a dealer because they’re all shit. That’s why people shit on them back.

It's easy to see why you think all dealers shit. Isn't it funny how certain people go through life running into almost no problems with anybody, while certain people have problems with everything and anything? It's not a coincidence.

 

[danm]

This might sound crazy, but did you check to see if any of your fuses were loose in the fuse box? There’s a thread on here about a number of Jeeps having loose fuses and causing weird issues. I wonder if this is an extreme case of that?

 

[coldstart]

It's easy to see why you think all dealers shit. Isn't it funny how certain people go through life running into almost no problems with anybody, while certain people have problems with everything and anything? It's not a coincidence.

What's funny is that some people are clueless idiots and never realize the truth. That's not a coincidence either.

I've only been lied to reliably by two organizations. Car dealers and the government.

 

[dalema]

OP - go get a professional involved and get those accident codes. Sounds like there are some folks on here that could advise on how to get that help.

I love how people jump all over someone for using their Jeep as designed and per the manual. The OP clearly knows what they are doing ie not a clueless person who hasn’t read the manual.

The fact you had issues just beforehand with the 4WD function that you had service look at, and then shifting like you should be able to into 4H results in what sounds like a failure of some sort in the system - sure sounds like the dealer screwed up in either missing something or sending you back out on your way in a dangerous vehicle.

Best of luck - sorry about your Jeep and what must have been quite a scare! Keep us updated.

 

[Zandcwhite]

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.

Unless of course it was the brake system that went haywire?

 

[FunWagon]

In my opinion look up your state’s lemon law. As soon as something happens document the hell out of it. Pictures of dash lights, of vehicle position, explanation of sequence of events.

I recently read up the lemon law in my state and basically you give a dealership two chances to fix a defect (especially one that endangers you) or X days in their hands, then you write the manufacturer a letter stating you’ve done so (my state provides a template/sample you can use). From that point, if I remember correctly, they have to correct it within 10 days or replace it/refund minus number of days it was used so far.

something like that.

 

[CJACKZ]

I too have owned several different 4wd systems (8i Toyota, 71 FJ5g, 76 FJ40, 86 S10 Blazer, 97 F150, 03 Expedition, etc). With the Toyota’s, I could “shift on the fly” and have 4WD as long as the hubs were locked. The F150 and 03 Expedition were all electronic. With both the Toyota’s true mechanical engagement, I never had an issue with shifting into 4HI at speed. Since we have had our JLUR, I have been shifting on the fly to help alleviate the stiffness at speeds up to 55. Today we had an unforcasted snow squal the blanked the road. I shifted into 4HI with no issues. The OP’s original post should have never happened IMHO. I agree with @dalema and others that you should enlist “experts” to resolve this.

 

[limeade]

How fast were you moving when you did your shift into 4wd HI? You have a Willys which comes standard with LSD so I think you locked the rear axle (like posted earlier) which caused loss of vehicle control. Let's assume a properly functioning transfer case, which may not be a good assumption considering your earlier discussion. When you shifted 'on-the-fly' from 2 HI to 4 HI, the transfer case locks both front and rear drive shafts and immediately attempts to spin the front driveline, which has been disengaged, to match the speed of the rear driveline at your current road speed. The inertial mass of your front driveline components being spun up to speed causes an abrupt counter force applied through the driveline to the rear axle which slowed both rear tires enough to "lock up" and lose traction and the jeep having a high center of gravity hit a snow bank or dropped off the shoulder and rolled.

It might be advisable in the future to slow to 5 mph or less, even coming to a complete stop at some safe location, to make any drive mode changes especially in ice and snow to avoid loss of vehicular control. I am glad you and the jeep are OK and hopefully this won't happen again. If your transfer case is having issues, this needs to get fixed immediately.

I would never shift on the fly into 4WD on a slick surface like that, at speed. I know lots of people get away with it, but it still is not advisable, per the last post above.

Another factor that may be in play is this. When traction control and LSD kick in, it is intuitive to counter-steer, which is the LAST thing you want to do when traction control is doing its thing during a skid. It counters for you. Corrective steering can make one lose control of the vehicle when traction control is working.

Not sure why any of you think you can't/shouldn't shift on the fly on a slick surface. The 4WD system is designed exactly for that! Your front wheel/tire assembly are already turning and there is no sudden application of force causing someone to lose control if engaging 4 Hi in this manner.

I would think it HIGHLY improbable that an LSD rear differential would cause this loss of control when engaging 4 Hi. If it were truly that slippery, the LSD wouldn't even be effective. Now if he had a locker engaged (whether mechanical or selectable) and was in a curve and he suddenly added strong acceleration, the locker could then cause a loss of control due to the rear wheels turning at the same rate.

In the OP's case, it seems as if there was some mechanical malfunction which caused an unexpected lock up of something which then caused an irrecoverable loss of control, which was not driver error. This is supported by his previous problems and visit to the dealer service dept.

I have over 30 yrs. of driving in snow (from the mid-west, to Alaska, the northern plains states, to the Sierra Nevada's) and have always had a lever operated transfer case. I have and continue to engage 4 Hi when conditions warrant and sometimes this means while I'm already on a slick surface. I have done this at higher speeds and have never lost control due to engaging 4WD.

Just last week I was on a road trip from Billings, MT to Las Vegas, NV and encountered multiple snow storms and poor road conditions. Several times I went from to 2 Hi to 4 Hi at speeds between 65 - 70 mph and yes I know the manual states going into 4 Hi at 45 mph and under, but it will without issue. In my experience, the transfer case doesn't want to go into 4 Hi above 70 mph.

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