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Discussion Starter #1
Bear with me, I am still a bit green when it comes to 4wd vehicles. I have owned a 4wd Nissan Frontier with a locking rear differential for over a year now. Over on the Nissan forums every time this subject comes up the short answer is "never use 4wd on pavement" presumably because it will either break, or cause disaster when you try to turn. Even on wet pavement the answer is no. The internet is full of hearsay and make-believe so I'm just not sure now.

I was looking at the Jeep website, and reading about the 4wd capabilities of the Wrangler and came across this:

When to use:

High range:
All road surfaces, including wet or snow-covered pavement, sand or gravel.
Low range:
Conditions requiring added low-speed power, technical driving, and situations when added torque is helpful (e.g. pulling a boat trailer out of water).

Based on the wording, Jeep is saying you can use 4HI on pavement? Does it have something to do with Nissan and Jeep having different 4wd systems or is it some other reason? With my Frontier there is no center differential so the front and rear become locked, and that seems like a bad idea when turning on pavement. What about Jeeps? They don't have a center diff either right?
 

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don't use 4wd on DRY pavement. if its snow covered or icey its okay. but not on dry. you don't need 4wd on dry pavement. ever. also, don't use lockers on pavement, wet or dry.
 

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Discussion Starter #3
Yeah that was my understanding of it. Thanks for the quick reply. Maybe Jeep needs to work on how they word things because they way it is described now it can be used on any surface including dry pavement. "All road surfaces" is very misleading.
 

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U shouldn't use it on dry, but if you do it wont automatically break like everyone thinks..
but then again, there's no reason you'd need 4 wheel drive on dry pavement.
 

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In a straight line - yeah it's no problem. As they mentioned, for example, pulling a boat out of the ramp. You may not even get your tires wet, but you could use 4-low to help get some extra torque and get that boat out of there...in a straight line.

It's because the transfer cases in the JK's don't act as a differential (I don't know what ratio of 4wd vehicles are like this, but if I had to guess I'd say it's most of them...I just know the JK's lol. But anyway...) If you're in 4-hi or 4-low, the transfer case is going to turn the front and rear driveshafts at the same rate, regardless of what direction you're heading (straight, turning, etc.).

Now think about when you turn - the outside tire follows a wider, longer line than the inside tire...it covers more ground. Hence the reason for limited slip differentials, spider gears, etc. The same idea applies to the axles themselves - the front and rear axles follow a different line when turning - one covers more ground than the other. This is where you can run into problems running in 4wd on pavement, even if it IS wet. The transfer case is pushing to turn both front and rear driveshafts at the same IDENTICAL rate, but when you turn one axle will be turning at a slightly slower rate than the other. THAT is where you can run into driveshaft problems - I've heard of some people snapping them running 4-high in the rain, on pavement.

General rule of thumb, I don't touch 4wd (high or low) unless I'm wheelin', or the road has to have ice or snow on it. Just rain? Keep it in 2wd. Not worth chancing a broken driveshaft. Sorry for the long winded description but I hope that adds a little more clarification, too :)

Best of luck with everything - you pick stuff up and learn every day! :beer:
 

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First, the JK has no differential or wet clutch between the front and rear axles; they are locked together. So when you are in 4WD (high or low), both the front and rear traction wheel must turn at the same rate. On dry pavement this will cause excessive force on the drivetrain during turns. Depending on the circumstances, this can cause parts to fail, but much more commonly it just causes excess wear.

In low-traction environments -- wet, icy, snowy -- the wheels have less grip on the pavement and the front and rear traction wheels can slip easier. So even though they still are turning at the same rate, less force gets put on the drivetrain due to lower tire:ground friction.

In any conditions, 4WD (high or low) is not a problem as long as you're going straight. It's when you turn that the front and rear tires need to spin at different rates, due to the different radius the rear tires versus the front.

So you should only use 4WD on pavement when it is necessary to get unstuck. Once you are moving, rely on proper speed to maintain control of the vehicle. If you have to rely on 4WD to maintain control in turns, you are driving too fast for the conditions. And 4WD will be much help when you have to stop.

The only difference between 4HI and 4LO is the gear reduction in your transfer case will give you more torque and better engine braking. In the JK, 4LO also disables ESP/BAS, which one could argue is not a good thing when driving on slippery pavement.

So yes, you can use 4WD on pavement, but should only do so on snow and ice when necessary.
 

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I was looking at the Jeep website, and reading about the 4wd capabilities of the Wrangler and came across this:

When to use:

High range:
All road surfaces, including wet or snow-covered pavement, sand or gravel.
Low range:
Conditions requiring added low-speed power, technical driving, and situations when added torque is helpful (e.g. pulling a boat trailer out of water).

Based on the wording, Jeep is saying you can use 4HI on pavement? Does it have something to do with Nissan and Jeep having different 4wd systems or is it some other reason? With my Frontier there is no center differential so the front and rear become locked, and that seems like a bad idea when turning on pavement. What about Jeeps? They don't have a center diff either right?
This is what the Owner's Manual says. It is more specific to the JK than the web site.

"4H Position
This range locks the front and rear driveshafts together,
forcing the front and rear wheels to rotate at the same
speed. This range (4H) provides additional traction for
loose, slippery road surfaces and should not be used on
dry pavement."

Personally, I wouldn't use 4wd on wet pavement. It's just not needed.
 

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i find this subject a little funny.

When we talk about 4wd on pavment whats the point you will never need it unless as stated your pulling a boat out of the water or just need extra traction for what ever reason. I think what we need to make clear here is YES you can and NO its not going to hurt anything you will find that the steering will bind while turning due to the u-joint style front axle shafts.

When we go wheeling at MOAB or RUBICON or even the Hammers we are driving in 4wd high or low all day on red rock, granite, or giant rocks which in alot of cases has more traction then concrete or black top. I know that we are not going hwy speeds all day but the diffeance is extreme when i am driving up hells revenge or i need to make a sharp turn with the steeing wheel at full lock with f&r lockers on going down hill on red rock with your suspenion maxed out, where is this any better on the "wear and tear" ...... its not and yet we do it all the time with no issues.

So if you want to use 4wd on pavment by all means do it, you wont hurt anything and just know that the steering will bind when going slow and turning. You will never put any more stress on your jeep then any of us that use our jeeps in exteme off roading.

its a jeep use it like one, utility civilian jeep, tractor... what ever just a little more refined for every day grocery getting. :thefinger:

just my 2 cents
 

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Discussion Starter #11
That is an interesting point there about MOAB. I've never thought about that since where I live its all dirt and mud. I don't plan on using 4wd on pavement I just thought it was interesting how it is worded on the website. The owners manual quoted above has a much better explanation of when to use it, which goes along with how I already understood it.
 

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So if you want to use 4wd on pavment by all means do it, you wont hurt anything and just know that the steering will bind when going slow and turning. You will never put any more stress on your jeep then any of us that use our jeeps in exteme off roading.
I agree, it's not and more difficult than when wheelin'. It's far from necessary or ideal..but it won't grenade. I've driven to work on bone dry pavement in 4-hi because people said it'd grenade. Nope...hardly even hopped anywhere. I wasn't doing donuts, but it's still together today.
 

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I just recently did a road trip from porltand Oregon to Lake Tahoe did the Rubicon then headed to San Jose at 75-80 mph then to The Golden Gate Bridge via 101, continued up 101 thru the red wood forest until crecent city and then jumped back on I-5 to Portland total milage 2000 miles.

When i got home i had a rotational squeek that i located to the rear drivline ( Tera Flex 1310 ). I took it off and sent the driveline out to my driveline guy where he rebulit it with high quality parts including 3" .288 wall dom tubing and better ujoints. During the time the driveline was out i was forced to drive the jeep with no rear driveline. Now here is where things get good.... i commute 130 miles a day 5 days a week. I drove roughly 700 miles in front wheel drive. I am currently running RCV shafts which make driving this way seemless. i still drove like normal on the freeway at 70 mph and the same way around corners the only diffreance was i was spinning just the front.

if you look at my sig you will see i have a lcg long arm kit with 5.38 gears and 37's.

My jeep still drives just fine and with do issues.


agian this is just my expericence
 

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Discussion Starter #14
Your situation is a bit different though because you didn't have the front and rear binding against each other. It's good to know the front driveline can handle that in a pinch though.
 

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Your situation is a bit different though because you didn't have the front and rear binding against each other. It's good to know the front driveline can handle that in a pinch though.
differant yes but this is just one senario that i used to show how durable it can be.

but after years of wheeling mulitipule vehicles i can tell you that this just a myth.

I use my jeep to its limits in all extremes from wheeling, to daily driving to rock crawling so i know what it can handle.

you should post some pics of your jeep i would like to see it.
 

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Discussion Starter #16
you should post some pics of your jeep i would like to see it.
I'm in the market currently. I own a 2010 Nissan Frontier Pro-4x which is a great truck, but I've always wanted a Jeep and the new 2012's are really nice Jeeps.
 

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I've driven to work on bone dry pavement in 4-hi because people said it'd grenade. Nope...hardly even hopped anywhere. I wasn't doing donuts, but it's still together today.

I've driven home from upstate (150mi) in 4 because I forgot to take it out...more than once in a 4Runner & a Durango. Never seemed to have an issue. I will try to remember to take it out of 4 with my JKU, though.
 
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