question for 4x4 owners

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V8Pathy
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question for 4x4 owners

Postby V8Pathy » Tue Sep 11, 2007 11:38 am

alright just tried the 4x4 feature last night ( first time on my 2008 Pathfinder).
I feel like I need to press a little bit more on the gas pedal to move the SUV: I understand you need to move the 4 wheels when going from 4x2 to 4x4. Just wondering if it is normal, I guess using the front differential use quite some power.

When I switch back to 2WD I get the power I'm used too on the freeway.

thanks !


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RacerZX
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Postby RacerZX » Tue Sep 11, 2007 1:26 pm

Do you mean 4 high or 4 lo? 4 high should be all but identical as 2wd, unless you're turning in which case yes it'll need a little more power to overcome the tire scrubbing. If you mean 4 lo, then the throttle is intentionally re-mapped to be less sensitive to give you more control.

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V8Pathy
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Postby V8Pathy » Tue Sep 11, 2007 2:52 pm

4hi and backing up/turning at the same time...it felt like I needed to press a little more on the gas pedal..

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Postby NVSteve » Tue Sep 11, 2007 3:13 pm

V8Pathy wrote:4hi and backing up/turning at the same time...it felt like I needed to press a little more on the gas pedal..
Was this on a solid surface?

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V8Pathy
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Postby V8Pathy » Tue Sep 11, 2007 3:32 pm

on grass/over the curb :)

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Postby RacerZX » Tue Sep 11, 2007 3:44 pm

> on grass/over the curb

Hahahaha... :D

It's just binding in the drive line, that's normal. When you turn in 4x4 mode you're forcing the tires to all turn at the same rate when they don't want to, so some extra power is needed to get the tires to slide a bit.

Imagine the 4 tire tracks on the ground as you continually turn, it's 4 entirely different paths. As you complete 360 degrees and look at the circumference of the 4 circles clearly some tires have rotated more than others right? And the tighter the turn, the more extreme the difference. A 4x4 system is going to fight you, trying to make it so all tires turn exactly the same amount, hence the need for some more power to make it do what you want. Being on a slippery surface, or having a limited slip center diff, will reduce this tendency, but it'll still be there to some extent.

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V8Pathy
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Postby V8Pathy » Tue Sep 11, 2007 4:15 pm

makes sense. Thanks !

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Postby V8Pathy » Tue Sep 11, 2007 8:46 pm

also it seems if you are turning (like a U turn on a one way street) it is slower or require more power..

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Postby NVSteve » Wed Sep 12, 2007 7:38 am

V8Pathy wrote:also it seems if you are turning (like a U turn on a one way street) it is slower or require more power..
First things first. You need to get out in the dirt. Even a small patch of dirt road will work, but that's when you can pop it into 4x4 and have at it. You can still feel the binding a bit in the dirt, and almost a shimmy effect when cranking tight turns. But, the dirt compensates for all of that because there is give under the tires, as opposed to no give when on a solid surface.

About your U turn, was it a real slow one, or was it at a pretty good clip? I haven't noticed any loss of power when doing U-turns, but I do notice that the VDC kicks in when I do things abruptly, which makes it feel like I'm riding on the back of a turtle.

Whatever the case might be, it would probably be a good idea to start documenting all the times you notice the drop in power. It will come in handy if something is wrong with the vehicle & you have to explain what's been happening.

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V8Pathy
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Postby V8Pathy » Wed Sep 12, 2007 8:13 am

thanks for the advice....will keep monitoring.

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Postby amr40509 » Wed Sep 12, 2007 11:20 am

I've had a lot of 4x4's and it seems like the less torque the more you notice power loss when locked into 4wd. Some examples are:

I had a '98 Ford Ranger w/ the 3.0L V6. On top of low power, it was a 5speed manual so it was even more noticable how much it was robbed of power. In 4wd on the road (like in snow) you had to REALLY hit the gas to get moving, you could really feel it.

I also rented a Jeep Wranger 4cyl in Aruba a few months ago to drive the back side of the island. It was also a 5speed manual. When starting from a stop I could tell that it was down on power in 4HI big time.

On the other hand, I can't really feel any power diff. in my Bronco w/ 400 V8 at all.

You are turning a whole lot more moving parts, and if everything isn't exactly even (same tire wear front/back, same EXACT gearing front and back) you are going to doing a little binding too.

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V8Pathy
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Postby V8Pathy » Wed Sep 12, 2007 2:26 pm

thanks for your input.
My Pathfinder has the 5.6L V8 with auto trans.

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V8Pathy
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Postby V8Pathy » Mon Sep 17, 2007 5:51 pm

I believe it is referred as " Heavy Tight corner braking symptom" on the Nissan Tech website.

See here:

http://www.nissan-techinfo.com/nissan/r ... er/DLN.pdf

page 120


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