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  #25  
Old 08-30-2010, 10:47 PM
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Re: No front ELSD for QD II?

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Originally Posted by vonk View Post
...But you do retain full torque for the traction wheel....
Maybe we have a problem here with nomenclature. In the Jeep forums, a locking diff transfer power to each wheel equally. We are speaking of LSDs, and yes, they may "lock" in your description, but it's only to one wheel at a time. I haven't gone further after reviewing the video link, and need to see if the electronic version can transfer power to both wheels as the graphic showed in 4Lo.
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  #26  
Old 08-30-2010, 10:55 PM
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Re: No front ELSD for QD II?

I will not purchase a $40k three wheel drive jeep. They can suck it before that happens. Inexcusable for Jeep to call it QD2. Picture yourself climbing a slipper snow covered hill. Do you really want the computer to apply the brakes to one of your front wheels to send power to the other? F that.
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  #27  
Old 08-31-2010, 06:02 AM
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Re: No front ELSD for QD II?

I've been driving a 3 wheel drive Grand since 1996 and in plenty of snow. It's been extremely sure footed.
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  #28  
Old 08-31-2010, 08:21 AM
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Re: No front ELSD for QD II?

That's great you have triple drive not quadra drive. Its a shame that my car would have more traction.
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  #29  
Old 08-31-2010, 08:36 AM
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Re: No front ELSD for QD II?

Have you read a test review yet that stated the "new" QD does not perform? There are plenty of brake application vehicles that do just fine off-road, so perhaps this will work out okay???
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Old 08-31-2010, 11:51 AM
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Re: No front ELSD for QD II?

Its the difference between "GOOD" and "GOOD ENOUGH". This is the top of the line trail rated jeep. If they are too cheap to give it a front LSD then consider me too cheap to buy one.
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  #31  
Old 08-31-2010, 12:27 PM
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Re: No front ELSD for QD II?

Sorry, but I wouldn't label this the "top of the line trail rated Jeep". That would be the Rubicon, and most guys mod from there. I think at this point the Grand Cherokee is being produced to take on the competition, and to be an answer to what people want from a larger SUV. They seem to have hit that squarely for the 95% of folks that buy these vehicles, and I think it's a home run. For what most of us do, the systems are in place. Possibly this doesn't meet your standard, but what other vehicle has LSDs at both ends in this "near lux" market? Personally, I would prefer Jeep catering to the masses, being profitable rather than continuing in bankruptcy, and not being able to produce anything!
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  #32  
Old 08-31-2010, 03:04 PM
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Re: No front ELSD for QD II?

Quote:
Originally Posted by Jim Hef View Post
Maybe we have a problem here with nomenclature. In the Jeep forums, a locking diff transfer power to each wheel equally. We are speaking of LSDs, and yes, they may "lock" in your description, but it's only to one wheel at a time. I haven't gone further after reviewing the video link, and need to see if the electronic version can transfer power to both wheels as the graphic showed in 4Lo.
You are so right about Terminology. Therefore, please bear with me as I try to clarify the principle of three Jeep-applicable differentials (IMHO J):

A locked differential is the equivalent of the right and left axle shafts being welded together. If both wheels have the same ground traction, they share torque equally. Off road, if one wheel becomes airborne, the wheel on the ground (traction wheel) gets all the torque, and the other gets none.

The LSD (Limited Slip Differential) derives its name from resisting relative rotation between the right and left axle shafts. This is done by hydraulically pressing a set of (clutch-like) friction disks together until their relative motion almost stops. A small internal oil pump (Gerotor) maintains hydraulic pressure while there is relative rotation between the axle shafts. While very effective, this system introduces a response lag while hydraulic pressure is being built up. However, it is self-contained and can potentially be installed wherever it fits.

This system alone cannot lock the differential, except by momentary application (by the car’s computer) of the slipping wheel’s brake until both wheels turn at the same speed. At that moment, an internal locking pin or other suitable device can turn the LSD into a “Locker”.

An ELSD (Electronic Limited Slip Differential) works much like the LSD described above. However, the friction disk compression is not done hydraulically, but by a magnetic device (cam plate) that can be controlled externally by electric signals from the car’s computer. This system has no response lag and it can lock the differential without use of brakes. Most importantly, it can be computer controlled for real time stepless adaptation to changing driving conditions.
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  #33  
Old 08-31-2010, 03:36 PM
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Re: No front ELSD for QD II?

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Originally Posted by Jim Hef View Post
Have you read a test review yet that stated the "new" QD does not perform? There are plenty of brake application vehicles that do just fine off-road, so perhaps this will work out okay???
Oh, I'm sure it'll work out okay. But, as a techie, when I spend that much money, I want it optimal.
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  #34  
Old 09-01-2010, 03:01 PM
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Re: No front ELSD for QD II?

Now that the Forum is back up and running, let's go further on this. From How Stuff Works:
"The locking differential is useful for serious off-road vehicles. This type of differential has the same parts as an open differential, but adds an electric, pneumatic or hydraulic mechanism to lock the two output pinions together.

This mechanism is usually activated manually by switch, and when activated, both wheels will spin at the same speed. If one wheel ends up off the ground, the other wheel won't know or care. Both wheels will continue to spin at the same speed as if nothing had changed."

That's what I was referring to as a "locker" diff...equal power to both wheels whether they are off the road/trail or not. What we need to get info on is what this electronically activated diff is doing...locking, or limiting the slip to one side or the other depending upon which wheel has more traction.
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  #35  
Old 09-01-2010, 04:40 PM
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Re: No front ELSD for QD II?

I kinda wonder why they chose to put the ELSD in the rear. In my experience pulling was more effective than pushing, so when adding a locker/lsd you'd add to the front before you'd add to the rear. For snow - front wheel drive is better than rear wheel drive, so why wouldn't a front ELSD be better than a rear ELSD? Unless the front axle on the WK2 is totally different than the front axle of the WK1, they already had a front solution - why put money into developing a new rear ELSD axle?
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  #36  
Old 09-01-2010, 07:21 PM
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Re: No front ELSD for QD II?

both axles are different on the WK2 if im not mistaken....
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