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******* SPACESTATION
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Discussion Starter #1
Can someone explain this for me?
I know how 4wd, transfer cases, etc work on 4x4 vehicles, but this AWD is a bit different.
From what the manuals say, the AWD sends power to the rear, until slippage is detected, then it engages the front.
When '4x4 Lock' is selected it locks up the front and rear drive shafts, so that atleast one wheel in the front and one wheel in the back have power all the time.
And '4x4 LO' is the same as above, additionally the transfer case shifts into low range.

Does that about sum it up?

Reason I ask: I was pulling out into heavy traffic yesterday and the tires broke loose. Made a nice loud squeal from the back, which caught me off guard since I was thinking it would engage the front drive shaft and grip rather than spin the rear.
Then as I was turning left to get into the lane I was aiming for, the tranny shifted into 2nd and the front tire chirped. This causes a bit of momentary torque steer and it's a good thing I had a decent grip on the wheel.

Is this normal, or was this an isolated incident?
I would like to think they engineered the AWD system to be a bit more smooth in operation.

thanks
 

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AWD differs from PT4WD as follows.

PT4WD has a solid locking member in the transfer case. Therefore, when in PT4WD, the front and rear driveshafts are solidly locked together so they rotate at the same speed.

AWD has an open differential in the transfer case. Therefore the front and rear driveshafts can rotate at different speeds. This means that the driveshaft with the least amount of torque will rotate. There is a slight bias in gearing between front and rear that makes the rear take more of the burden.

As far as breaking the tires loose, that generally only happens when you are turning a corner and some of the wheels dont have much traction and spin.
 

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Discussion Starter #3
That explains why the front driver side tire chirped, since more of the weight was on the pass side as I was turning left.
Next time I guess I will give it less gas.
 

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well it is fun to hear the tires chirp occasionally. Reminds me of the power of my beast ;)
 

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lostsoul trapped in time
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TRANSFER CASE: NV144HD
Availability Std. with 4.7L engine
Type Single-speed, electronically shifted
Operating Modes AWD; Locked (4 Lock)
Low-Range Ratio None
Center Differential Planetary
Torque Split, Front/Rear 48/52

TRANSFER CASE: NV244HD
Availability Opt.—Included with 5.7L engine
Type Two-speed, electronically shifted
Operating Modes AWD; Neutral; Locked (4 Lock); Locked (4 Lo)
Low Range Ratio 2.72
Center Differential Type Planetary with lock
Torque Split, Front/Rear 48/52
 

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Discussion Starter #6
so, since I have the NV244HD, if I have it in 4 lock, or 4 lo, then atleast 1 tire in the front and the back will turn at the same speed?
I thought their would be some type of traction device in the rear diff.
 

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lostsoul trapped in time
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i wish there were a way to modify that ratio to place more power to the rear during AWD
 

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Discussion Starter #8 (Edited)
i wish there were a way to modify that ratio to place more power to the rear during AWD
I wish it was split 50/50. It happened again earlier today, I went to pull out and both the back tires started howling.
I can't seem to get on it off the line without spinning / barking both the back tires.
I don't want to stick it in 4 LOCK every time I need to pull out quickly.
AWD should prevent wheel spin and grab rather than leave big black marks.
I can't believe, as heavy as the Durango is, that I am having a problem with rear wheel spin.
could be due to the fact it's only got 265/70/18 (33x10.5) tires
 

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lostsoul trapped in time
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do you have traction control? I have the nv144 tranny with no traction control. Just AWD and 4lock and even if I jump on it from a stop, I can't spin the rears, maybe because of the 4.7L....
 

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I have to REALLY stand on the gas to get my wheels to spin at all, and even then I have to turn the TC off to do it. 5.7L with AWD and traction control.
 

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Discussion Starter #11 (Edited)
Post #10
I have to REALLY stand on the gas to get my wheels to spin at all, and even then I have to turn the TC off to do it. 5.7L with AWD and traction control
That's another thing thats strange. If I put it down about 1/2 way quickly I get wheel spin, if I nail it the front & rear bite and it takes off.
It could also be the surface that I am driving on. I pull out into traffic at the same point everyday, it's white / gray concrete asphalt (like they have at gas station lots).

edit: it does have the ETC and yaw control (whatever the hell that is) and I leave it on. According to manual, only time I should turn it off is when stuck in snow/mud.

do you have traction control? I have the nv144 tranny with no traction control. Just AWD and 4lock and even if I jump on it from a stop, I can't spin the rears, maybe because of the 4.7L....
you have a 545RFE tranny, the NV144 is the t-case. Mine came with the NV244, but I think they operate the same, just different power handling ratings.
That's one reason I drove 2.5 hours to get the Hemi Durango, all the dealers in the local area have 4.7 models. After test driving a couple of them, I just couldn't deal with it.
If I'm going to pay at the pump, I atleast want to have fun in between fill ups.
 

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I have a limited 5.7L AWD and I have never been able to chip my tires but I don't abuse it either since I don't think its too smart to put that much stress on an AWD system.
 

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Discussion Starter #14
Big3 said:
I have a limited 5.7L AWD and I have never been able to chip my tires but I don't abuse it either since I don't think its too smart to put that much stress on an AWD system.
sorry about that, but how is putting the pedal 1/2 way down quickly to pull out in traffic abuse?

Trust me, as much as I paid for that thing abuse is last on my 'to do' list while driving.
Furthermore, their is a reason they put a NV244HD t-case and 545FRE tranny in the Durango, because it's heavy and the Hemi puts out enough power to warrant HD parts.
The entire reason I bought a Hemi is so I can merge with traffic, and so the truck can get out of it's own way.
This post was started because I wanted to know why the AWD system was letting the tires spin instead of grabbing and going.
 

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I love it when my Durango breaks all four tires when accelerating! I don't do it intentionally but it's kind of cool when it does happen, but it only occurs when turning right or left into traffic. My front wheels pick up the slack pretty quick when the rears start slipping resulting in excellent control and acceleration.

Another advantage of AWD - a crazed driver in a Tahoe side-swiped me on the freeway at 70 mph, taking out my front right fender and nearly ramming me onto the soft shoulder. Immediately after impact I accelerated hard to pull the vehicle straight. Glory to God for His allowing me to remain on this earth another day.
 

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Discussion Starter #16
Big Cypress said:
I love it when my Durango breaks all four tires when accelerating! I don't do it intentionally but it's kind of cool when it does happen, but it only occurs when turning right or left into traffic. My front wheels pick up the slack pretty quick when the rears start slipping resulting in excellent control and acceleration.

Another advantage of AWD - a crazed driver in a Tahoe side-swiped me on the freeway at 70 mph, taking out my front right fender and nearly ramming me onto the soft shoulder. Immediately after impact I accelerated hard to pull the vehicle straight. Glory to God for His allowing me to remain on this earth another day.
yeah, mine will spin the tires when the weight shifts, and will chirp them from a straight line acceleration.

Gotta watch out for those bow tie drivers :D
Glad you know who is in charge though.
The boss got me through OIF I and back home to my wife & daughter in one piece.
 

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not sure what kind of Durango you guys are driving, but the only way to break all 4 tires loose at once would be if you have front AND rear lockers and you were on a gravel road, and you still would probably need some HP mods to even think about doing this.

Most likely you are breaking loose the one front tire when it is unweighted in a turn from a stop.
 

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Discussion Starter #18
Doesn't the limited come with a traction aid in the rear diff?
 

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The only way to get the LSD was to order it as a separate option. I got a fairly fully loaded SLT, and the LSD was not part of any option package.
 

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Canyon Runner's right. All four tire's do not break loose simultaneously but rather one from each axle is more likely what's happening. I know for a fact my difs are completely open :(
 
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