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-   -   Quadra Drive II - drive to front wheels (http://www.jeepgarage.org/f109/quadra-drive-ii-drive-to-front-wheels-67753.html)

lt4vette 11-09-2013 05:01 PM

Quadra Drive II - drive to front wheels
 
While looking for a solution to a whistle on overrun in my 2014 JGC Overland ORAII, I came across an SRT thread where they have the same problem. A probable cause seems to be faulty front CVJ's. When someone asked about a non-SRT with the problem, the response was that for the CVJ's to cause the whistle, there had to be power applied to the front wheels, which is not the case with QDII.
I have watched videos and got conflicting answers to the question:
Does QDII apply any drive to the front wheels under normal (good traction, highway) conditions, or is torque only sent to the front wheels if the rear has reduced traction?

Can anyone enlighten me?
Thanks

bill_de 11-09-2013 05:09 PM

Re: Quadra Drive II - drive to front wheels
 
Jeep.com has a pretty good description and animation of the system. AFAIR the power is distributed front and rear during normal driving.


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lt4vette 11-09-2013 06:06 PM

Re: Quadra Drive II - drive to front wheels
 
Quote:

Originally Posted by bill_de (Post 927320)
Jeep.com has a pretty good description and animation of the system. AFAIR the power is distributed front and rear during normal driving.


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Thanks Bill. I couldn't find any animations for Quadra Drive on that site, although I did find one on youtube at How Quadra Drive Works - YouTube
This seems to show that under normal conditions, no torque is sent to the front wheels - which I think is unusual.
The next question for me though, relative to my overrun whistle, is what resistance is being overcome by the front wheels on the overrun, even if they are not being driven when the throttle is applied. Unless its virtually zero, faulty cvj's could still make a noise - I think.

bill_de 11-09-2013 06:26 PM

Re: Quadra Drive II - drive to front wheels
 
Try this link;

Jeep - 4x4 Basics - How Jeep 4x4 Systems Work - Quadra-Drive II - 4WD SUVs

AAAA 11-10-2013 11:24 AM

Re: Quadra Drive II - drive to front wheels
 
Simply put there is Quadra-Drive I and there is Quadra-Drive II. Jeep likes to make improvements and keep using the same names (such as Cherokee).

ColdCase 11-10-2013 02:25 PM

Re: Quadra Drive II - drive to front wheels
 
The only difference between quadra drive II and quadra trac II is how the rear diff works. There may be better description of quadra trac about, but the amount of bias is a function of the mode selected, sport being biased to the rear. There is always some torque being delivered to the front (for safety and stability control), but it varies. Usually 50/50.

Oh, the you tube video is of the old WJ system which is mechanical and autonomous. The WK2 is electrical, controlled by the traction computer, and operates differently. Some dealer techs don't know this. In the old mechanical system power was not applied to the front axle unless there was wheel spin, or you shifted the transfer case into locked mode.

lt4vette 11-10-2013 03:26 PM

Re: Quadra Drive II - drive to front wheels
 
Thanks all for the advice. I am confident that the original comment I read that no torque was transmitted forward was wrong. So the CVJ's remain a potential source of my overrun whistle.


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