[Rick Anderson]

I guess mainly what I am trying to understand, and forgive my ignorance, is how does an AWD system of the Durango or Explorer match up with a traditional 4WD set-up like my Command Trac in real-world performance. Since I have rarely used the 4-Lo setting, for my needs it's not a deal breaker. What I am wondering is how does a AWD system compare to 4-Hi as far as distribution of power to the four wheels. I know AWD systems are not all the same, but in general. I have done a lot of research on this, and it seems a little confusing at times because everyone has an opinion and they sometimes conflict...like most things in life I guess.

The new AWD systems in the Jeeps use the ABS to maintain traction and control slip, etc. In a way its best of both worlds, but honestly it can't beat good old fashioned brute all 4 wheels locked at the same speed.

From your description, it doesn't sound like you need or used your part time 4WD for serious off roading, mudding and obstacles. So you will probably like the modern AWD systems and they will meet your needs.

By definition they are AWD, but they are always engaged full time 4WD, all open differentials, with a slight torque bias to the rear wheels, often a free wheeling unit to the front wheels so the front wheels don't back drive the xfr case. Making for smooth driving on pavement in dry or wet. The ESP/BAS system will use ABS and throttle control for traction and stability control (which you can turn off if desired). But it will also use ABS to energize brakes at wheels that spin and slip, i.e. the old one wheel stuck in mud that all the power goes too and leaves you stuck, it won't happen, the brake on that wheel will energize to limit its slipping and force power to the other wheels and get you moving/keep you moving. It turns all the open differentials into virtual limited slip differentials (granted a locking or true lsd does it better, but this system still does a pretty good job for most situations). The higher end versions of the AWD systems often have electronically controlled clutch systems to act like smart LSD's and to lock the differentials as well, to include at the XFR case. As well as give you 4WD low, that locks the XFR case as well.

Command Trac is just Part Time 4WD, the xfr case has a locked differential and your option to engage 4WD or RWD. And you can only engage 4WD in conditions where the wheels are slipping, otherwise you'll get driveline binding. Wet roads, engaging part time 4WD will cause wheel spinning in turns and you're more likely to loose control than gain any advantage from traction in straight line conditions. But, for serious off roading, it gets power to all 4 wheels very efficiently.

If you want to rock climb, spin wheels across a mud pit and do serious off roading trails and obstacles, the Command Trac will do better in those situations, as well as the suspension and ground clearance of the older Jeeps/Durango's. At the cost of NOT doing as well in most on road conditions, including poor weather and light snow on road.

If you want a good road manners, good in bad weather, and still respectable off road, the newer AWD systems will do that. NOT as effective for real challenging off road stuff like Command Trac, but then again, if you want to do that the suspension and ground clearance of the newer vehicles are also going to be a hamperment. Deep snow, the AWD system could probably do pretty well, the problem is going to be the ground clearance of the newer vehicles is going to hang you up sooner compared to some of the older vehicles. They are still going to be capable of off road stuff, its just a matter if they are as good as some of the older versions.

 

[TheMan]

You were fine up to this:
"Command Trac is just Part Time 4WD, the xfr case has a locked differential and your option to engage 4WD or RWD. "


Command Trac or any other fixed, part time system does NOT have any differential AT ALL.

 

[LouJC]

Only Selec Trac had the lockable differential. Open in full time and locked in part time.

 

[TheMan]

Only Selec Trac had the lockable differential. Open in full time and locked in part time.

Not true. NVG had several models that had a differential. The 242 was only one of them.

 

[TheMan]

You were fine up to this:
"Command Trac is just Part Time 4WD, the xfr case has a locked differential and your option to engage 4WD or RWD. "


Command Trac or any other fixed, part time system does NOT have any differential AT ALL.

NVG231 PARTS EXPLOSION above. Show me the differential by id number (hint: look at item 44)

NVG 242 PARTS EXPLOSION above. Compare thus image to above 231 (note item29 above. THAT is the locking and unlocking diff.

 

[LouJC]

I was thinking of the more recently used ones Bob, I know NVG used some selectable cases further back than the 242...

 

[TheMan]

I was thinking of the more recently used ones Bob, I know NVG used some selectable cases further back than the 242...

Still wrong. There were 8 models SINCE the 242 that had the selectable diff. Many were used in the various military models of the HMMWV by AM General. Also other vehicles.

 

[TheMan]

I was also wondering about the AWD system of the Durango. I currently have an 03 Liberty Renegade with the Command Trac part time system. I am in the market for something newer and larger because we now have kids, so I would really like something with 3 rows. Unfortunately I have a job where no matter what it's doing outside, I have to go in. Rain, blizzard, hurricane...doesn't matter. My Liberty has gotten me through all of it, and I would like something at least as capable if possible. I have an hour commute that isn't so fun when it's nasty out. I should say I lived in Central NY state for 12 years, most of it with a Ford Escort, so I have a pretty good idea how to drive in just about anything...I just like the added capability of 4x4 to compliment good common sense! Lol

We've been looking at the Durango, the Explorer, and the Enclave. It appears the Durango's system is the most similar to what I have already, but the 2 speed transfer case is only available in the RT it appears. It is my understanding that the single speed transfer case in the Durango is similar to what is available in the Explorer and the Enclave? My wife wants the Explorer or the Enclave, so I probably know who will win this, but I want some more ammunition for the battle. Any advice/input is helpful!

If saving money is an option, as opposed to changing a vehicle to a new one, keep you current one and swap out the transfer case and propshafts to a 242. Cheep to do and it consists of bolting in the parts.

If you are really feeling froggy.....there is a cast steel front axle housing available (at least the was a couple years ago) from the aftermarket that used Dana guts and accepted ARB air lockers.

 

[Zagnut27]

If saving money is an option, as opposed to changing a vehicle to a new one, keep you current one and swap out the transfer case and propshafts to a 242. Cheep to do and it consists of bolting in the parts.

If you are really feeling froggy.....there is a cast steel front axle housing available (at least the was a couple years ago) from the aftermarket that used Dana guts and accepted ARB air lockers.

Bob, I really have thought about doing some mods to my Liberty, but there are 2 reasons why I probably won't. One is, we need a bigger vehicle because our twins have so much stuff to carry around right now. Two is, she will be 13 in September and recently more things have been breaking making her not very cost effective to keep and maintain. Still not sure, maybe we will trade in my wife's Encore for an Enclave...and then I can trade for either a JKU or that fabled Jeep pickup that always appears in the distance....lol. You have given me something else to think about though...she's been a good dog, I kinda hate to give her up.

 

[Zagnut27]

You were fine up to this:
"Command Trac is just Part Time 4WD, the xfr case has a locked differential and your option to engage 4WD or RWD. "


Command Trac or any other fixed, part time system does NOT have any differential AT ALL.

I'm a little confused. I have a front and rear differential, but you mean there is no differential between the front and rear wheels to allow for full-time 4wd? (Sorry, just want to make sure I understand what I think I know already).

 

[Zagnut27]

The new AWD systems in the Jeeps use the ABS to maintain traction and control slip, etc. In a way its best of both worlds, but honestly it can't beat good old fashioned brute all 4 wheels locked at the same speed.

From your description, it doesn't sound like you need or used your part time 4WD for serious off roading, mudding and obstacles. So you will probably like the modern AWD systems and they will meet your needs.

By definition they are AWD, but they are always engaged full time 4WD, all open differentials, with a slight torque bias to the rear wheels, often a free wheeling unit to the front wheels so the front wheels don't back drive the xfr case. Making for smooth driving on pavement in dry or wet. The ESP/BAS system will use ABS and throttle control for traction and stability control (which you can turn off if desired). But it will also use ABS to energize brakes at wheels that spin and slip, i.e. the old one wheel stuck in mud that all the power goes too and leaves you stuck, it won't happen, the brake on that wheel will energize to limit its slipping and force power to the other wheels and get you moving/keep you moving. It turns all the open differentials into virtual limited slip differentials (granted a locking or true lsd does it better, but this system still does a pretty good job for most situations). The higher end versions of the AWD systems often have electronically controlled clutch systems to act like smart LSD's and to lock the differentials as well, to include at the XFR case. As well as give you 4WD low, that locks the XFR case as well.

Command Trac is just Part Time 4WD, the xfr case has a locked differential and your option to engage 4WD or RWD. And you can only engage 4WD in conditions where the wheels are slipping, otherwise you'll get driveline binding. Wet roads, engaging part time 4WD will cause wheel spinning in turns and you're more likely to loose control than gain any advantage from traction in straight line conditions. But, for serious off roading, it gets power to all 4 wheels very efficiently.

If you want to rock climb, spin wheels across a mud pit and do serious off roading trails and obstacles, the Command Trac will do better in those situations, as well as the suspension and ground clearance of the older Jeeps/Durango's. At the cost of NOT doing as well in most on road conditions, including poor weather and light snow on road.

If you want a good road manners, good in bad weather, and still respectable off road, the newer AWD systems will do that. NOT as effective for real challenging off road stuff like Command Trac, but then again, if you want to do that the suspension and ground clearance of the newer vehicles are also going to be a hamperment. Deep snow, the AWD system could probably do pretty well, the problem is going to be the ground clearance of the newer vehicles is going to hang you up sooner compared to some of the older vehicles. They are still going to be capable of off road stuff, its just a matter if they are as good as some of the older versions.

Lots of good info. The problem is, I have had to drive over some obstacles in my Liberty and through flooded roads as well on my way to work. Not often, but it has happened enough. We've had probably a half dozen hurricanes since I've had her, not to mention the Nor'Easters as well where I've encountered fallen trees and standing water. I do need the ground clearance and water fording ability...granted the Liberty was never a super off-roader, but she got me through. These new crossovers don't look like they have much in the way of clearance. Just concerned about getting hung up, but then I got hung up on deep snow in the Liberty that never would have stopped my Wrangler.
Not sure what to do. I think maybe we'll replace my wife's car instead with a larger crossover, and then I'll get a JKU or Wrangler pickup (here's hoping!) so then I CAN take it off-roading and have some fun. Or as Bob suggested, mod my Liberty...what the heck, she's old (and paid for), why not learn how to do some cool things with her?

 

[TheMan]

I'm a little confused. I have a front and rear differential, but you mean there is no differential between the front and rear wheels to allow for full-time 4wd? (Sorry, just want to make sure I understand what I think I know already).

No there is not.

Not for the 231 case.

From the image where the differential would go (which is why i hinted at the part ID number) you have a solid shaft with splines that carry a sliding gear that engages the front drive shaft.

 

[Zagnut27]

No there is not.

Not for the 231 case.

From the image where the differential would go (which is why i hinted at the part ID number) you have a solid shaft with splines that carry a sliding gear that engages the front drive shaft.

So if I had a full time system, I would have a differential there to allow the front and rear wheels to spin at different speeds when the system is engaged. Since I have command Trac, the front and rear wheels are locked together when engaged, hence why you don't use it unless slippery conditions.
Thanks Bob, I am learning at a geometric rate. Pretty soon I will become self-aware, and trigger the end of the human race...or something like that...lol

 

[TheMan]

In concept, yes....that simple. In practice there are other parts involved that complicate matters.

See Dan's excellent response to the issue of judging self awareness (middle of page. Click on the video link)

https://www.allpar.com/forums/threads/an-is-fixing-the-9-speeds-just-a-“snap-”.160455/page-2

 

[Zagnut27]

In concept, yes....that simple. In practice there are other parts involved that complicate matters.

See Dan's excellent response to the issue of judging self awareness (middle of page. Click on the video link)

https://www.allpar.com/forums/threads/an-is-fixing-the-9-speeds-just-a-“snap-”.160455/page-2

Ha! I love that video, my brother (computer programmer) had shared it with me before when I was participating in a leadership forum for process improvement...a whole lot of 6 sigma drudgery...long story short, we were tasked with building a tool to assess risk of 30-day readmission for heart failure patients but were saddled with completely unrealistic parameters, so of course it failed but the sad part was no one from above cared anyway. What a waste of frigging time. Anyway, the video brought it home for me and made me smile.

"Like a lot of things in life, we laugh because it's funny, and we laugh because it's true."--Al Capone, The Untouchables.

 

[LouJC]

Also keep in mind that when in full time mode this differential in the transfer case will allow wheel spin at one end of the vehicle if the front tires or rear tires are on a very slippery surface like ice. So in winter conditions, full time works well most of the time but when the snow gets really deep, you are on ice, or have to climb steep hills in snow, part time will give better traction. I drove our '98 Jeep with the 242 through many north east winters and found it to work very well, but it does not do the same thing as that Quadratrac or the later Quadradrive systems that can shift power from the rear to the front axle based on wheel spin.
The 242 requires a little knowledge on the part of the driver. No electronics to fail, I wish they still offered it.

 

[MoparNorm]

I'm a little confused. I have a front and rear differential, but you mean there is no differential between the front and rear wheels to allow for full-time 4wd? (Sorry, just want to make sure I understand what I think I know already).

Bob answered your question, but yes, the 242, which I have and bolts right into your KJ, also has the center differential, as did the 229 and other Quadratrac cases.
The 242 is still my favorite and a 242HD is found in the H1 Hummer.
The 242 can shift power to the front or rear automatically and can also be shifted into Part Time to mimic the 231, wish I had it in my Wrangler.

 

[LouJC]

Norm.... Don't think the 242 can shift power at all but the 249 Quadratrac could
If you put the rear wheels of a 242 vehicle in full time on ice and the fronts are on snow it will probably spin the rear wheels and may not move. You should use part time in those conditions A 249 or 245 will send power forward and move the vehicle.

 

[MoparNorm]

Norm.... Don't think the 242 can shift power at all but the 249 Quadratrac could
If you put the rear wheels of a 242 vehicle in full time on ice and the fronts are on snow it will probably spin the rear wheels and may not move. You should use part time in those conditions A 249 or 245 will send power forward and move the vehicle.

Part Time locks front and Rear together, but Full Time will still transfer power, to a percentage, depending upon if you have a limited Slip rear axle. Think of the Part Time as a selectable locker, from the standpoint of front vs. rear. Part Time is "locked" Full Time is "Open" withing the operating range of the differential and any limited slip axles.
It does not have the same type of traction sensing couplings as the 229 or other Full Time transfer cases, but it is very robust for a Full Time case.

 

[Zagnut27]

Bob answered your question, but yes, the 242, which I have and bolts right into your KJ, also has the center differential, as did the 229 and other Quadratrac cases.
The 242 is still my favorite and a 242HD is found in the H1 Hummer.
The 242 can shift power to the front or rear automatically and can also be shifted into Part Time to mimic the 231, wish I had it in my Wrangler.

I saw on a blog where some guy swapped a 242 from a Durango to his Dakota, and he included pics of each step involved. Didn't seem too difficult, although he had some issues with different connectors for the indicator switch...I assume I would not have these issues if swapping a 242 from another Liberty? (Apples to apples?) I could probably find one in a pick and pull, that's where I got my front driveshaft a few years ago, unless someone is making these for aftermarket (I didn't look into that)?

Problem is, I just don't have the time for this right now. With our 5-month old twins, on most days when I'm not working, I don't have the time to S3, much less devote time to gleefully ripping apart my Liberty (for constructive purposes of course!!). We are avoiding daycare for now, and next year we will most likely be in position to buy something new...probably a bigger SUV/CUV of some sort. If it doesn't replace my Liberty, then maybe I can make some interesting changes or save that money for my next purchase...a JKU or the fabled Jeep truck! I would like a toy with all the creature comforts that I have grown to love, and will keep my co-pilot happy.

As always, I appreciate greatly the advice, and all of you have given me a lot to think about (visions of sugar plums...or transfer cases...dancing in my head...lol!!)