Jeep/Dodge/Auto/Manual transfer case swap compatibility?

It may have an electric transfer case shifter and that would be a rotary switch on the dash. None of the older Rams that I am aware of had full time

4WD and I doubt that the Daks did either. I can't say for the newer ones but I don't remember seeing it on the web site.

If your question is "Can you use the automatic transfer case with the manual?", I don't know, but I doubt it. The Jeep is a viscous drive unit AWD and the Ram with the manual NV3500 has the low/high 2wd/4wd manual New Departure unit. When acquiring the gearbox, get the transfer case with it. Then, worst case is a UJoint change/ drive shaft mod and they are easy. Remember, you can sell those removed parts easily on eBay and use the money to offset the cost of the project. It is really what you want anyway. Those viscous drives kill UJoints and mileage. Does the Jeep have the vacuum/electric front axle disengagement mechanism like the 1500 Ram? Steve

This is one of the more responsive and informative forums I've found :-)

Things are looking good for this ZJ 5.9/5spd/4WD swap. Looks like the only fab or custom work would be trans x-member, d/shafts and maybe the TC linkage. Maybe less than that if I look around. Still looking at that PCM VIN thing but I'm starting to think that inspection issue isn't as big a deal as I thought it was.

True - If I just keep the TC that comes with the NV trans then it isn't an issue but it would be nice info to have - whether there is a "clocking" issues swapping TCs Dodge to Jeep. That is - the bolt pattern or spacing may not be the same. I'll try that question on the Jeep forums too.

Is the 4Low gearing an integral part of the TC geartrain or could it be eliminated and still have 4WD-N-2WD capability? I'll see if I can google an exploded view of the TC. Did any Mopars ever have a TC that just went 4WD-Neutral-2WD without the low? I doubt it.

TB - It may well have had the Explorer style switch somewhere but it looked like the only stuff in the center dash was AC and Radio. Not much else but I was only peeking in the window. I'll check it again.

SL - Ya, the VCs are a pain and don't seem to last too long. Anything kills them. Uneven tire wear, wrong size spare, mismatched tires etc. I don't mind the AWD except for the poor VC durability. I don't have any real reason for 4LO and from what I've read 2WD doesn't help the gas mileage by more than 1-2 mpgs if that and doesn't make much of a difference in performance in the quarter mile or anything. I guess it's nice to be able to do burnouts but I don't see too much use other than that except you get a dependable TC.

I do know a lot of the Jeep wheelers change to the 242 or the 247 to eliminate the VC issue and there is a hybrid someone told me about that can be built. 247/249 I think. I have the info somewhere.

Mine is def the NP249. AWD 4LO-Neut-4HI w/no motor on the front axle. I think that is the SelecTrac which I think is the 247. Mine does have a vaccuum line to the Tcase but I'm not sure what it's for.

I was a mechanic for many years both professionally and backyard but I never dealt with

4WD stuff til I got my Jeeps. Actually I did work on one AWD vehicle. A nice little foreign car that topped out at 205mph and cost close to a quarter mil even back then in 97'. No cross application experience from that ha ha.

SL - You're right on the money about the used parts offsetting the cost. Doing that again as a side business to offset my costs came to mind just the other day.

Back in the day I used to fund my engine swapping on fullsize Mopars (mostly C bodies) by selling the old parts and the parts from the donor cars. I made money on that and realized later that if I had chosen cars with a better following I could have made some serious money.

I'm thinking of primarily ZJs (93 to 98 Grand Cherokees) and maybe Rams and Daks and if it got big enough I could branch out into XJ Cherokees and WJ (99 to 04) Grands too. Probably best to start out on a vehicle by vehicle basis til I see how it goes.

Not to mention it'd be a great way to make use of the $30K worth of tools that are wasting away in storage. They're sitting right next to my complete 62 New Yorker dashboard, big block Holley/Carter carbs, electronic distirbutors and a valve body to convert the 64 and earlier push button cable 727s to the 1965 only cable 727 operated w/ column shifter. (66 went to linkage)

Sheesh, why do I go on like that? These start out as replies and then evidently turn into "stream of concious" things. Thanks for bearing with me.

Talk to you soon - John

Ha! Here I go again, two steps forward, one step back.

I am vaguely familiar with that axle motor setup from pictures but I'm not sure how that works in conjunction with the Tcase. Which of the following is more correct: A. The Tcase removes power to the front driveshaft and the axle motor floats the diff to reduce effort/friction/wear at the front axle. B. The axle motor takes the front axle out of the picture BY floating the diff.

IIRC - Jeeps have that front axle motor setup too on some manual applications like XJs and possibly the 93 4.0

5spd ZJ. In the meantime I'll go check my Chiltons Jeep manual and google a bit to see if I can figure out the answer from that.

I'm going to assume it's the first option, Tcase removes power to front dshaft and axle motor simply reduces effort etc. So if I put the Ram Tcase in my Jeep without the motor type front axle I get 2WD but I don't reduce the effort and improve the gas mileage etc?

Here's a scary question. If you installed the electric motor type axle on an AWD (full time -VC) vehicle and activated the motor to float the front diff, what would happen? Would it wreck the VC because there wouldn't be any resistance on one side or would I just blow something up? :-)

What does the hose on the Tcase on my Jeep (46RE w/VC tcase) do or is that just a vent?

Thanks again - John

That would be option A.

That would be correct and Dodge has also removed the axle motor from the newest line of 4X4 Rams.

It would overheat and damage the VC, drop your mileage considerably, and do no good at all. AWD means just that, AWD. I had a friend who's daughter had a Subaru and her's was an AWD. She put new tires on the rear of her car and they were a size smaller than the front and within a few weaks, destroyed the AWD unit. IOW, they don't like the be screwed around with. :-)

Follow it and see where it goes.

Steve L/TBone

So what do the Rams use now that they got rid of the motorized floating diff front axle?

I'm finally realizing there was never an AWD 5spd (w/ VC Tcase) application then? I've heard of people removing the Jeep V8 front d/shaft for whatever reason, they reported not much difference in gas mileage. By doing that on the VC style Jeeps they are ruining the VC then?

I know having even slightly different diameters on the tires damages the VC. Different widths front to rear doesn't matter right?

My Jeeps VC is already bad. It does the jumpy/jerky thing in tight parking lot turns etc. Now, I still have 4WD right? And that 4WD is now more or less the same as a Ram would be in 4WD? In my case removing the d/shaft or floating the diff couldn't damage it any further right? I don't plan on removing it but I was wondering about using the floating diff axle. With the bad VC is it actually split 50/50 or whatever now the way a regular transfer case splits it?

Does a bad VC actually affect mileage? My Jeep still averages just over 13 mpg which is normal for the 5.9 ZJ from what I hear. In fact I'm actually getting 14.5 mpg now that my second gear is gone cuz I've been babying it lately.

So, the ideal setup for mileage would be to get the front axle from a Jeep with Commantrac to use with this setup? I'll have to research those two. I don't even know if CommandTrac or SelectTrac was an option on ZJs or if the front diff setup from other Jeeps would fit the ZJ.

I just did a quick search and read up on the "using 4WD all the time" controversy. So you folks with 4WD truck generally don't use 4WD except in snow and maybe rain right? I'm going to have to rethink how I want this Tcase setup to work.

More research!

I see part time 4WD is also an option with Selectrac.

The select lever engages either 2wd high or 4wd high or 4wd low. I am not certain on the following, but there are 2 scenarios. The first, a micro switch is tripped when selecting either of the 4wd options. The micro switch illuminates the 4wd indicator on the dash and a solinoid opens a vacuum line to the front axle or the lever operates the vacuum valve and vacuum is transferred to the axle where the axles are coupled to the carrier. When the axles are locked to the carrier, a micro switch is tripped illuminating the dash indicator. I think the latter is the case. This eliminates free wheeling hubs as a requirement. Steve

Nothing.

That I don't know but probably not.

I doubt that they are doing this on the VC style jeeps and if so, then the transfer case would need to have the ability to return to 2WD or part time

4WD which effectivly removes the VC from the drive line.

As long as they are the same diameter, there shouldn't be any real issues as far as the VC goes.

That sounds like it is locked or siezed. Are you sure that you are in AWD and not part time 4X4.

IF the VC has siexed, then you are acting in a part time 4X4 mode and continuing operation like this will put excessive strain on the drive train. Removing the front drive shaft will relieve this problem but if the VC were to free up, you probably would be stranded.

If it is siezed then yes, a 50/50 split.

Probably not if it is siezed. It may actually improve the mileage slightly but will put excessive strain on the drive line in corners.

This I don't know.

Part time 4WD is not intended for full time use. A part time 4WD locks the front and real axles together which is fine in a straight line. The problem is when you turn the vehicle, the front and rear axles are moving at different speeds and the part time 4WD has no way to relieve this as that is what the VC does. That is why you feel that "hopping" in tight corners with your jeep. In the snow and ice, the wheels can slip to relieve this pressure but on a dry road.....

Which does nothing more than lock up the VC.

You got it... the lever on the transfer case actuates a vacuum switch, that switches vacuum from one line to the other running to the CAD (central axle disconnect) on the front axle. This actuates a vacuum motor which moves the shift fork, sliding a locking collar over the inner and middle axle shafts on the passenger side. On the other side of the vacuum motor on the CAD is a switch that controls the 4WD light. Note that as soon as you pull the lever on the transfer case, it's transmitting power to the front axle. The

4WD light is only indicating whether or not the front axle is locked.

OK, learning more everyday thanks to you guys and also crossreferencing everything on the forums etc.

Jeep ZJs were offered with CommandTrac, SelecTrac and QuadraTrac depending on the drivetrains.

My 5.9 (all V8 ZJs I believe) has the QTrac NP249 Tcase with only 4HI

- N - 4LO. Part time

4WD isn't an option unless you swap TCs. For Mopars I guess the 249 is only a Jeep and Durango thing.

For more on the disco'd front d/shaft thing, a post from JF debates it a bit.

So some people are doing it whether it's wise or not. Some differing opinions offered there on how bad it is for the VC.

Mods Woody and EMTimZJ advise against it. (Interesting note - they have both done

5spd ZJ conversions) Woody - a 4.0 5spd, Tim - Project Tortoise, his 94 5.2 5spd w/link to build. Both are off road builds. Tortoise is pretty extreme. The hybrid 249/247 TC is briefly mentioned here. Someone recommended it for my swap. I'm wondering if my VC is actually gone or not. It has a noticeable hop turning into a tight parking space at like 1mph but I don't feel it at any other time. Maybe it is only on it's way out, not gone yet? I've heard that when they're on their way out they may only exhibit the symptoms when they get hot. Mine seems to be the same all the time.

I'll have to put some more thought into what I want for the Tcase part of this swap. In many ways I like the way the Jeep is now. I don't have to think about the Tcase on any surface in any season but it would be nice to be able to go to 2WD and also to get better mileage with the floating diff. I suppose replacing my front axle might bring whole new compatibility questions (I think)

In any case I'm not sure the 249 will fit any 5spd as there may be that clocking issue between the Jeep and Dodge Tcase mounting.

I'll bounce a few of these questions around the Jeep forums and let you know what I find.