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Another issue. 4 hi

oldcjguy

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While trying to figure out my error codes something else happened that none of my previous 4x4’s have done.
I put it in 4 hi. Made a u turn on my home street. As I was turning, the front jumped and acted like I was trying to turn a locked front axle. But I dont have lockers. If I put in 4 hi I should be able to drive it on asphalt or hard pac without it freaking out. Once home I hooked up my flashcal to see errors. It showed the u0432, and the U0010. These are what I was trying to diagnose.
anyone experience this?
It was because of the tight turn. Front wheels spin at different rates than the back because they can change angles. This will cause some binding and I'd consider that normal. Depending on when you put it in 4 hi and started the turn if the FAD hadn't fully engaged until you were in the turn it could feel like a jump. If you put it in 4hi and drive straight for a few feet with some minor turning then do the same test it might feel different. With warm dry tires on a clean high traction asphalt it could feel like that. The jump is just the unbinding as a wheel let loose to self correct the binding.
 

acsak

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My understanding is that the transfer case in a part time full wheel drive system behaves similarly to a center locking diff, and it may be helpful for all of us to think of it that way when switching into 4-Hi. Some transfer cases actually have a differential (think G-Wagon full time AWD like Subaru) which would allow for full lock steering on dry pavement without binding and hopping but these do not - and so they require a driving surface that allows some slip. It makes sense that the front axle felt like it was locked at its diff when it wasn't because the transfer case "locks" the rear and front drive shafts together.

The same thing used to to happen to me when I was driving my dad's Tacoma in high school. I used to like the feeling and extra "grip" of driving "fast" (in a 4-cylinder Tacoma....) in 4-hi on back roads but I would get that hopping on tight turns and didn't understand what it was or care to address it. Knowing what I know now about 4 wheel drive systems I'm surprised I didn't do some damage to the drive train. I did this pretty often for several years, and while I absolutely DO NOT recommend driving part time 4-hi on dry pavement I never broke anything on that particular vehicle. I only tell this story to illustrate that this can happen on vehicles other than Wranglers. I'm surprised to hear that you've never experienced this on other vehicles. I'd be curious to know more about how why that is. You briefly listed some other vehicles you've driven in 4-Hi without that hopping. Do you know what their transfer case set ups are like?

An interesting point was made earlier about wheelbase and turning radius. I drive a 2DR JL and have felt that hop on pavement earlier than I expected when accidentally leaving the Jeep in 4-hi. Maybe that's because the turning radius is tighter and there's more travel to full lock. Seems to me that with that further travel we'll experience hopping for a greater proportion of the turning radius in 2 doors.

Anyway I wish I could help more with the OP trouble codes, but I thought it'd be helpful for others who may stumble upon this thread and who may be new to this kind of driving to know that this can happen on Jeeps and all other 4-wheel drive vehicles that have a part time (as opposed to full time AWD), non-differential transfer cases. We should remember that these systems rely on the ability to slip on wet or loose surfaces to release energy. If the outside wheel while turning can't release the energy from its extra speed through a differential or surface slip it may have to release that energy by breaking a drive shaft component, and that absolutely can and does happen. That sounds like a bad day to me.
 

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And even to be fair, it didn’t even hop, tires never even skidded. It just felt jumpy. ?
You didn't drive it in circles in 4H so I think you are good. It has happened to me driving around a corner in soft dirt and hitting rocks on the other side. It will jump and bind somewhat. The first time it happens it gives you an Oh S%$@ feeling.
 

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You didn't drive it in circles in 4H so I think you are good. It has happened to me driving around a corner in soft dirt and hitting rocks on the other side. It will jump and bind somewhat. The first time it happens it gives you an Oh S%$@ feeling.
Youre ducked too. Itll explode, sooner or later.
 

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zouch

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considering that we're spending multi-tens of kilobocks on a multi-ton piece of machinery that we expect to operate on (and off) highways we share with the general public, taking ourselves and people we care about to places we want to go and hopefully get back from, i don't think it the least bit unreasonable to read the Owners Manual before Operating.

you'll learn more about it by reading the manual than by using it, and it'll likely cost you less in the long run.

show of hands, who all sat down at the dealer and read your manual cover to cover before you drove away from the dealership? I am getting through all of this new info. I’ve only got 500 miles on my vehicle it’s not like I’ve had this for thousands of miles and should know everything yet.
 

Zandcwhite

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considering that we're spending multi-tens of kilobocks on a multi-ton piece of machinery that we expect to operate on (and off) highways we share with the general public, taking ourselves and people we care about to places we want to go and hopefully get back from, i don't think it the least bit unreasonable to read the Owners Manual before Operating.

you'll learn more about it by reading the manual than by using it, and it'll likely cost you less in the long run.
If you need to read the owners manual in order to drive the vehicle, it's already too late and I respectfully request that you stay off of public roads. Vehicles are not some new technology that requires study and an advanced degree to operate. If you rent a car, do you waste hours of vacation reading the manual? How on earth do vallets manage to have time to read thousands of owners manuals? The nuances and idiosyncrasies are irrelevant to the fundamental operation of the vehicle. There is a reason that the accelerator pedal is always on the right, the turn signals are down for left and up for right etc. We've owned more than 20 vehicles in the last 25 years and I've read 0 manuals. Add in rentals, driving friends vehicles, company vehicles, etc and there's likely 2 dozen more. How on earth do I manage to drive 60k+ miles every year without issues and while maintaining a clean driving record? Maybe I've been doing it wrong this whole time? Let me guess you read the directions for hooking up a TV or operating a new lawn mower too?
 

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FRONT/REAR POWER DISTRIBUTION

A part time 4-wheel drive, found on Wranglers, is ideal for off-road, while a full time 4-wheel drive, found on SUVs, is ideal for road use.

full time 4-wheel drive is actually 2-wheel drive (e.g. front drive only) or 70/30 front/back (for example) by default. When it detects slippage of grip then it reacts to it by changing the power ratio front to back to 50/50. So it REACTS to changing conditions, which is great on the road. But off road a system that reacts to change is too slow to react. It’s not ideal. You want power going to front and to back to be locked at 50/50, so you ALWAYS have grip on loose ground.

This is how I understand it. Also been driving Jeeps for a while, so familiar with the feel on and off road.

If the ground does not “give” while turning when locked 50/50 front/back then it binds and hops. Happens sometimes on solid road when forget in 4H and turning slightly.

LEFT/RIGHT POWER DISTRIBUTION

Also, while 4H (and 4L) lock power going to front and rear 50/50, keep in mind that left to right it is not locked, so wheel spinning more gets all the power, which is great on the road because the wheel spinning more is the wheel on the outside when turning making a bigger circle (one wheel spinning faster on the road means you are turning!). But off road if one wheel spins faster than the other side then it means the wheel spinning faster is up in the air of has no grip on the ground and sending all the power to it does nothing.

This is where front and rear lockers (on Rubicon models) come into play, to enable you to lock power to wheels 50/50 left and right.

You usually try locking the rear wheels (50/50 power left/right) first. Since rear wheels always point forward (no steering) then less likely to bind.

If that is not sufficient to get the Jeep moving then you also lock the front wheels 50/50 left/right, but need to watch out for binding. So it takes experience and judgement. You learn as you experiment with it.

Jeep Wrangler JL Another issue. 4 hi 81FBE1B2-2F9D-45E3-9FEF-445CF2574F53


Left diagram: Part time 4WD is on locking power 50/50 front/back (when in 4H or 4L). Note that power left/right (in front and back) will go 100% to wheel spinning faster not both left and right.

Right diagram: Rear differential is locked sending power 50/50 left/right in the back. Note that 4L must be on, as in left diagram, sending power 50/50 front/back using low gears.

center diagram: Front differential is locked, sending power 50/50 left/right in the front. Note must be in 4L and rear lockers already on to add front lockers.
 
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zouch

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clearly, some people *do* need to read a manual. (note that even the OP stated he doesn't understand everything about his new vehicle; understandable, but i don't want to ever be That Guy.)

whether or not you choose to read the manuals is clearly a personal choice. but if you want to fully understand your equipment and know how to get everything out of it, trying to just use it is rarely going to get you there. (same thing with your lawn mower, and/or your electronics.)
for people that are satisfied with only the basic fundamentals of operation, that's great for them, i guess. they're likely to not know what they're missing, and apparently Ignorance really is Bliss.
hopefully it doesn't end up costing them (or anyone else!) anything. i've spend enough time involved with Emergency Services to know that's not always the case.

rental cars? no, i don't generally read those, though i have found interesting and/or useful info in them at times. but they're not mine, and i'm not going to be doing anything interesting with them and/or living with the consequences of anything done wrong to one.
cars i've borrowed? absolutely. people that have loaned me equipment have extended their trust to me. (amusingly, some still call me to ask me questions about their vehicles for answers they could have gotten reading the same manual i did.)



If you need to read the owners manual in order to drive the vehicle, it's already too late and I respectfully request that you stay off of public roads. Vehicles are not some new technology that requires study and an advanced degree to operate. If you rent a car, do you waste hours of vacation reading the manual? How on earth do vallets manage to have time to read thousands of owners manuals? The nuances and idiosyncrasies are irrelevant to the fundamental operation of the vehicle. There is a reason that the accelerator pedal is always on the right, the turn signals are down for left and up for right etc. We've owned more than 20 vehicles in the last 25 years and I've read 0 manuals. Add in rentals, driving friends vehicles, company vehicles, etc and there's likely 2 dozen more. How on earth do I manage to drive 60k+ miles every year without issues and while maintaining a clean driving record? Maybe I've been doing it wrong this whole time? Let me guess you read the directions for hooking up a TV or operating a new lawn mower too?
 

Zandcwhite

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clearly, some people *do* need to read a manual. (note that even the OP stated he doesn't understand everything about his new vehicle; understandable, but i don't want to ever be That Guy.)

whether or not you choose to read the manuals is clearly a personal choice. but if you want to fully understand your equipment and know how to get everything out of it, trying to just use it is rarely going to get you there. (same thing with your lawn mower, and/or your electronics.)
for people that are satisfied with only the basic fundamentals of operation, that's great for them, i guess. they're likely to not know what they're missing, and apparently Ignorance really is Bliss.
hopefully it doesn't end up costing them (or anyone else!) anything. i've spend enough time involved with Emergency Services to know that's not always the case.

rental cars? no, i don't generally read those, though i have found interesting and/or useful info in them at times. but they're not mine, and i'm not going to be doing anything interesting with them and/or living with the consequences of anything done wrong to one.
cars i've borrowed? absolutely. people that have loaned me equipment have extended their trust to me. (amusingly, some still call me to ask me questions about their vehicles for answers they could have gotten reading the same manual i did.)
Not sure what complex feature you think I'm not getting my full use of, thanks to the tazer I get full use of things the factory won't let you. Want to check behind you while not in reverse? Double tap the mute button and the rear view camera comes on. Want to disconnect the sway bar and lock the rear diff for some fun drifts out in the desert? I do that too. If you're talking radio presets or adaptive cruise functions, those systems are intuitive. Some of us prefer to figure it out through using it, but to each his own. I'm 100% certain there's not a single feature or use case I'd learn from a lawn mower manual though.
 

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Arterius2

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Not sure what complex feature you think I'm not getting my full use of, thanks to the tazer I get full use of things the factory won't let you. Want to check behind you while not in reverse? Double tap the mute button and the rear view camera comes on. Want to disconnect the sway bar and lock the rear diff for some fun drifts out in the desert? I do that too. If you're talking radio presets or adaptive cruise functions, those systems are intuitive. Some of us prefer to figure it out through using it, but to each his own. I'm 100% certain there's not a single feature or use case I'd learn from a lawn mower manual though.
I thought the same.

But after reading these forums and re-reading the manual I did find random interesting things that I did not know before. Like autopark, neat hill descent feature, rear camera delay, hidden compartment that allows you to shifts to neutral when battery dead etc.

Also.

Chill the fuck out.
 

Zandcwhite

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I thought the same.

But after reading these forums and re-reading the manual I did find random interesting things that I did not know before. Like autopark, neat hill descent feature, rear camera delay, hidden compartment that allows you to shifts to neutral when battery dead etc.

Also.

Chill the fuck out.
It's always the emotional ones telling other people to chill out? Your sensitivity is showing. I was never worked up. I never said nobody should read the manual. I pointed out it isn't some necessity, especially for those of us who prefer to be hands on. If I need the jeep to do something I can't figure out, I'll Google it far faster than you'd find it in the manual. Most of the neat features I use on the jeep aren't in the manual anyway (like disabling the seat belt chime). Take a deep breath and relax, I apologize that my differing opinion got you all worked up.
 

Arterius2

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It's always the emotional ones telling other people to chill out? Your sensitivity is showing. I was never worked up. I never said nobody should read the manual. I pointed out it isn't some necessity, especially for those of us who prefer to be hands on. If I need the jeep to do something I can't figure out, I'll Google it far faster than you'd find it in the manual. Most of the neat features I use on the jeep aren't in the manual anyway (like disabling the seat belt chime). Take a deep breath and relax, I apologize that my differing opinion got you all worked up.
Not a great place to tell people not to read the manual while on a thread about making mistakes because of not reading the manual. It's great that in your personal experience, not reading the manual hasn't let to any regrets. But be cautious when advising others.
 

Zandcwhite

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Not a great place to tell people not to read the manual while on a thread about making mistakes because of not reading the manual. It's great that in your personal experience, not reading the manual hasn't let to any regrets. But be cautious when advising others.
I don't think the op's "mistake" has led him to any regrets either, as clearly no damage was done. He learned by doing that u-turns on dry pavement in 4 wheel drive are not advisable and make the Jeep unhappy. I'd argue just based off average test scores that most people wouldn't retain the bulk of the info even if they sat down and read the manual cover to cover. If you have a question, by all means look it up. If you want to read the manual, go for it. I don't see it as a necessary step in Jeep ownership, but you do you.
 

mwilk012

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I can see there are a lot more angry people on here than I thought. I asked a simple question. You saw that I asked the question from the dealer and I got no answers. So I came here. And several people would rather just tell me basically how stupid I am. And no I do not sit down every time I buy something and read the manual cover to cover who the hell does that. No worries see you guys I’ll just start taking my question someplace else.
It’s not about you not reading the manual so much as a complete lack of understanding as to how your vehicle operates. When the front and rear are physically locked, and you take a sharp turn, the front turns faster. Something has to give.
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