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-   -   Why is Quadra Drive only available with the V8 & Diesel? (http://www.jeepgarage.org/f109/why-is-quadra-drive-only-available-with-the-v8-and-diesel-65110.html)

JWS360 09-06-2013 10:57 AM

Why is Quadra Drive only available with the V8 & Diesel?
 
Why is Quadra Drive only available with the V8 & Diesel?

I never could figure this out. Why isn't QD available across the line, even if at an extra cost? Shouldn't V6 owners have the option of an arguably superior 4WD system?

AZhiCntry 09-06-2013 11:23 AM

Re: Why is Quadra Drive only available with the V8 & Diesel?
 
A locker is needed in very few situations. The ABS torque transfer system (traction control) works very well. Here is some info of real world experience without the locker in V6s. http://www.jeepgarage.org/f73/no-gc-for-me-65102.html

The V6 uses a smaller rear diff and the ELSD will not fit inside the diff of a V6.

mazster43 09-06-2013 11:29 AM

Re: Why is Quadra Drive only available with the V8 & Diesel?
 
I believe the rear axle for the V6 is not compatible for the Quada Drive II.

whartung 09-06-2013 01:50 PM

Re: Why is Quadra Drive only available with the V8 & Diesel?
 
Quote:

Originally Posted by mazster43 (Post 888738)
I believe the rear axle for the V6 is not compatible for the Quada Drive II.

Now, I am not a automobile engineer, but...

So does that mean that that the V8 has a different drive shaft than the V6? Why would they need different drive shafts? The V8s torque is mightier enough over there V6 that it needs to be larger? Other than that, isn't it just a coupling, couldn't they have mated the coupling to the V6 to drive the ELSD?

Just curious.

mazster43 09-06-2013 02:01 PM

Quote:

Originally Posted by whartung (Post 888836)

Now, I am not a automobile engineer, but...

So does that mean that that the V8 has a different drive shaft than the V6? Why would they need different drive shafts? The V8s torque is mightier enough over there V6 that it needs to be larger? Other than that, isn't it just a coupling, couldn't they have mated the coupling to the V6 to drive the ELSD?

Just curious.

It's possible they have a common drive shaft. A couple variables in that like rest axle input and transfer case output, how they attach. Higher torque on the v8 and diesel would be a reasonable guess as to the different rear axles. QD2 on the v6 may have a separate thread. Try searching for it, i know it's been discussed in one of the diesel threads.

AZhiCntry 09-06-2013 02:05 PM

Re: Why is Quadra Drive only available with the V8 & Diesel?
 
Quote:

Originally Posted by mazster43 (Post 888738)
I believe the rear axle for the V6 is not compatible for the Quada Drive II.

Quote:

Originally Posted by whartung (Post 888836)
Now, I am not a automobile engineer, but...

So does that mean that that the V8 has a different drive shaft than the V6? Why would they need different drive shafts? The V8s torque is mightier enough over there V6 that it needs to be larger? Other than that, isn't it just a coupling, couldn't they have mated the coupling to the V6 to drive the ELSD?

Just curious.

;)It means that the V6 uses a smaller rear diff that the ELSD will not fit inside.
Could they put a V8 diff in the V6? Yes, but cost more $ and might affect MPGs and the real world need/demand for ELSD is just not enough to justify the cost/logistics of providing that option in the V6. I believe that Jeep thinks that anyone looking for maximum off road performance would get the V8.

Brett 09-06-2013 06:41 PM

Re: Why is Quadra Drive only available with the V8 & Diesel?
 
I'm pretty convinced that the quadra trac is more than sufficient most of the time, however I do prefer to have the elsd for peace of mind.

Pretty cool utube of an old commander with quadra drive:

Jeep Commander Quadra Drive II / The best stock automatic system - YouTube">Jeep Commander Quadra Drive II / The best stock automatic system - YouTube" type="application/x-shockwave-flash" width="425" height="350">

JWS360 09-07-2013 08:37 AM

Re: Why is Quadra Drive only available with the V8 & Diesel?
 
Quote:

Originally Posted by mazster43 (Post 888841)
It's possible they have a common drive shaft. A couple variables in that like rest axle input and transfer case output, how they attach. Higher torque on the v8 and diesel would be a reasonable guess as to the different rear axles. QD2 on the v6 may have a separate thread. Try searching for it, i know it's been discussed in one of the diesel threads.

I recall the old 4.7 L V8 had QDII--and a far less powerful engine than the current V6. Don't know why the axles/driveshafts, etc wouldn't share parts commonality. Would seem to make sense that they would.

Maybe its a way to get people to buy an unwanted or not needed bigger engine.

Peter_K 09-07-2013 10:55 PM

They might use the same driveshaft as an example, but they just as likely don't. It could be because of higher torque loading with one engine vs another, or simply because one engine/transmission/transfer case combination is longer or shorter length-wise requiring different driveshaft lengths. Why not specify the engine/transmission/transfer case lengths to be the same? That might be a more expensive option as opposed to simply having different shaft lengths, and it my not be technically feasible with some combinations.

ColdCase 09-19-2013 01:02 PM

Re: Why is Quadra Drive only available with the V8 & Diesel?
 
Quote:

Originally Posted by JWS360 (Post 888718)
Why is Quadra Drive only available with the V8 & Diesel?

I never could figure this out. Why isn't QD available across the line, even if at an extra cost? Shouldn't V6 owners have the option of an arguably superior 4WD system?

The V6 doesn't have enough power to spin the wheels :)

The QD diff always seems to be in short supply. Even when offered across the line, it was restricted to vehicles with upscale options (more profit).

My theory, however, is that its a marketing decision.. perhaps the thinking is that the V6 isn't suitable for those conditions that require a locker, and that customer satisfaction would require a bit more low end torque. but I think the bean counters have determined how to manage resources to maximize profit.
You want QD, you have to buy also buy plenty of bells and whistles as the entry fee.

Or the ELSD is needed for the SRT launch control, so it was pretty straight forward to also put them in V8s as they use the same housing and then amortize the costs.

4jeepdiesel 09-19-2013 01:27 PM

Re: Why is Quadra Drive only available with the V8 & Diesel?
 
Yet another reason to get the diesel


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