2WD to 4WD conversion

[Jax MJ Luvr]

curious, how tough would it be if I were to purchase a 2WD and convert to 4WD.. I know I'd have to buy the NP 231 transfer case to start.. I'm sure the center console and lever I could snag at a salvage yard.. how much is really involved? since I'm not overly mechanically inclined, but I know friends that are and can help...

 

let me know what parts I would likely need , cost & time involved.. since I've heard other people do it, but never heard what was really involved.

[Pete M]

Personally I feel it's the best way to build a Comanche. :D

Start with the size engine you want, A/C or not, auto or manual, and longbed or shortbed. These are the important choices as they are the hardest changes to make. The rest is bolt-in if you stick with Jeep parts. At the very least you'll need :

-4wd trans and t-case (the best way to buy them together),

-front driveshaft from an MJ/XJ that has the same engine/tranny that you have so you know it's the right length,

-t-case shift linkage, shifter assembly, and that little bracket that bolts to the body to support said linkage,

-Rear shaft from a 4x4 MJ with the same engine/trans (or have the 2wd shaft cut down)

-MJ/XJ front axle that matches your rear gear ratio (this can either match the stock one or hopefully you can get a better ratio to match the bigger tires I'm sure you want, then get a rear axle to match) I recommend a non-CAD axle that has the bigger U-joints.

-If you buy a rear axle, I recommend an 8.8 axle from a 95+ Ford Explorer which is stronger than a Dana 44 and can be found with 3.54/3.73/4.10 gears, disk brakes, and posi (any rear axle that didn't come from under an MJ will need new leaf pads welded on)

-And get a factory shop manual too. If you buy an 87-88 truck, get the 89 shop manual. It's better than the older ones and the trucks are essentially the same.

There are a lot of little details and particulars that can give you headaches when you try to mate everything up, so when you find something, ask about it before you plunk down money at the junkyard.

Jeep on!

--Pete

[mjeff87]

Ditto what Pete said (thanks Pete, you save us alot of typing :wink: )

 

I did mine over the course of time, and did alot of other stuff to it while I had it off the road. I spent about a year gathering parts...when I saw something I needed for a good $$$ I bought it and stashed it. My total cost was about $300, courtesy of the junkyard and offsetting the price of what I bought by selling what I took off during the swap.

 

It's the absolute BEST way to get to know your MJ, and you have the satisfaction that you built it instead of bought it.

Jeff

[Jax MJ Luvr]

hey found a couple really good web links... for any others interested in the 2wd to 4wd conversion and the Ford 8.8 swap :)

 

http://xjfanatic.com/4wd1.php

 

 

http://members.cox.net/rough-riders/tec ... rd8_8.html

 

Both seemed to be very informative, even to a mechanically deficient perseon as myself.. saw a bunch of other sites available with tons of info and instructions how do todo this stuff. It's going to help me a ton, hope it helps others :)

[xjblue]

Timely post, I need to reaserch this topic as well

 

So far I've only got a front axle cut from a rolled 89 XJ but it's missing shafts on one side, my thinking at the time was I wanted to upgrade the shafts and joints in it any way.

 

I've been debating back and forth on finding a good 4.0 aw4 np231 doner XJ or keeping it 2.5 for budget

[Pete M]

Careful with axles from rolled vehicles. The dana 30 is a light duty axle and can bend from even a mild looking roll depending on the circumstances that caused the roll. A slow roll offroad is usually fine, but an onroad roll is tricky due to the increased forces involved. It would suck to put all the effort into an axle that can't be aligned (or worse) due to a slight bend in it.

Jeep on!

--Pete

[Jax MJ Luvr]

ok, lucked out again, found another MJ real close to home... it's a 92, automatic, 6 cyl... but 2WD... I can ge the truck for $1000 cash.. maybe less if I wave the $100 bills in his face 8)

 

I just need a little reassurance on what I'll need to buy to convert it and how tough will it really be... if I'm not mistaken, I'll need to buy a new transmission, transfer case and a front axle... correct?

 

will the conversion be straight forward bolt on type thing or will I need to recruit my master mechanic and 4 wheeler friends to help make modifications to get any loose ends to work properly?

 

if it's something I can do in a relative short time span, once I get all the parts, then I'm going to try to drive down tonight and snag this puppy... hope to hear some reassurance :wink:

[Pete M]

Not only is it completely bolt-on if you buy the right parts, but you don't have to do the whole conversion at once. :D You can swap in the front axle one day, trans/t-case on another, rear axle on another, lift on another. Just make sure you refurbish the parts before you put them on the truck. It would stink to find out that the brakes are bad *after* you put the new axle on the truck. And always plan on something going wrong. Bolts always seem to snap when the stores are closed and you need your ride in the morning. :(

Jeep on!

--Pete

[Jax MJ Luvr]

sweet! I already checked out a few other sites online just to double check the process to convert to 4WD, looks very promising and my mechanical experience may be just enough, but I'll still have my master mechanic on call or just looking over my shoulder to be safe.. I plan on heading down Sunday morning with cash in hand and hope to bring the lil' 92 2WD home with me... I'll let you know if it all pans out for me :) got my fingers crossed again :wink:

 

plus I already found a tranny and xfer case locally for $750... but I'm sure I can try to negotiate the price down... I'm just going to concentrate on getting the MJ in my possession 1st :!:

[bigwormskidoo]

done a couple conversions already very easy to do don't hesitate on trying it it is worth every effert you put into it about to start on my 92 mj very soon

[clarkerussell]

Is it possible to use the transfer case from a full time 4x4 cherokee? Would the axles need to come from the same XJ?

 

Before I go any further, is the full time 4x4 a piece of crap that I'm wasting time on? I don't plan of going rock climbing, I just want a good 4x4 for winter use. Thanks!

 

Clarke

[DirtyComanche]

Then you want full time.

 

 

With part time, if you say, lose traction while braking or going around a corner, generally you will with all the tires. Well, that's what I hear, and I think that I could agree as I've drove mine in harsh winter ice. Also you are technically only supposed to use it 'part time' which I never bother with, just don't turn corners and you're okay!

 

 

Only disadvantage of the 242 I know of is the SYEs for it might suck. I'm not sure. Never looked into swapping mine as I didn't blow up my 231 before I got the SYE for it.

[Pete M]

The np-242 case is a fine t-case. Aftermarket parts are catching up slowly, but surely. The shifter may be a bit different so make sure you get the right parts for it.

The problem with the part-time cases (np231, dana 300, etc.) is that no vehicle's front tires turn at the exact same rate as the rear tires (the descrepency is even more if you turn a corner). If you drive on pavement that won't allow a tire to slip and take up the slack, drivetrain-bind can cause all sorts of complications and destruction. The awd cases (242, etc) allow slippage and you can drive on dry pavement with no worries.

Jeep on!

--Pete

[clarkerussell]

Do you know if the NP-242 is compatible with a manual tranny? I currently have a Peugeot 5 speed.

 

 

The np-242 case is a fine t-case. Aftermarket parts are catching up slowly, but surely. The shifter may be a bit different so make sure you get the right parts for it.

The problem with the part-time cases (np231, dana 300, etc.) is that no vehicle's front tires turn at the exact same rate as the rear tires (the descrepency is even more if you turn a corner). If you drive on pavement that won't allow a tire to slip and take up the slack, drivetrain-bind can cause all sorts of complications and destruction. The awd cases (242, etc) allow slippage and you can drive on dry pavement with no worries.

Jeep on!

--Pete

[Pete M]

Compatible with a manual tranny? Yes. But you may run into a spline count issue with the ba-10. All Peugeots will have a 21 spline output shaft. The earlier years of 242s might have the 21, but I'm not positive. But I 'd take the opportunity to upgrade to an AX-15 while I was at it. Of course, the early years of those had 21 too, so you'll need to be careful what you buy.

Jeep on!

--Pete

[mjeff87]

There's a couple of guys on NAXJA that run a 242 behind a manual tranny. It was never offered from the factory, but it is possible so long as you match input spline/depth like Pete said.

Future plans for my MJ include a 242 behind my AX5, hopefully in the spring. You might have to have your rear driveshaft length altered-there's about a 1" length difference between the 231 and 242. I've got my old 2WD shaft sitting under my house I'm planning on having cut to length and rebalanced when I swap cases (if my current one won't work).

Jeff

[HatchetMJ]

I've got a 2wd and am going to be in the next couple weeks getting a donor XJ and doing the swap myself. I'll try and take pictures and do a little write up while I'm at it. However my conversion is going to be with an AX5(replacing the factory AX4) and a NP231. All bolted behind a 2.5L...but its basicaly the same for the 4.0 guys. Just different parts.

[xjblue]

I think I'm leaning towards what Hatchet plans, have the same drivetrain w/ AX4, What is the scoop on the AX5 vs the AX15?

[Pete M]

AX-5 is the 5speed version of the AX-4 and both bolt behind the 2.5L. The AX-15 is its big brother (more like a close cousin actually) that bolts behind the 4.0L. The AX-15 won't bolt directly to the 2.5L, but can be adapted using the bellhousing from a 2.5L Dodge Dakota that had the AX-15 (and some other stuff to finish the swap).

Jeep on!

--Pete

[HatchetMJ]

I think I'm leaning towards what Hatchet plans, have the same drivetrain w/ AX4, What is the scoop on the AX5 vs the AX15?

 

The AX15 is a stronger more reliable tranny..the synchro's don't go out on them nearly as much as the AX5's do. I will say that I have seen an AX15 converted to be mated up to a 2.5L engine but it was a PITA and not something I would want to do. However if you've got the time, patience, and ability to do so it would be a good swap. And add some strenght and reliablity to you drive train.

 

HTH

[MiNi Beast]

On 8/24/2005 at 1:20 PM, Pete M said:

Personally I feel it's the best way to build a Comanche.

Start with the size engine you want, A/C or not, auto or manual, and longbed or shortbed. These are the important choices as they are the hardest changes to make. The rest is bolt-in if you stick with Jeep parts. At the very least you'll need :

-4wd trans and t-case (the best way to buy them together),

-front driveshaft from an MJ/XJ that has the same engine/tranny that you have so you know it's the right length,

-t-case shift linkage, shifter assembly, and that little bracket that bolts to the body to support said linkage,

-Rear shaft from a 4x4 MJ with the same engine/trans (or have the 2wd shaft cut down)

-MJ/XJ front axle that matches your rear gear ratio (this can either match the stock one or hopefully you can get a better ratio to match the bigger tires I'm sure you want, then get a rear axle to match) I recommend a non-CAD axle that has the bigger U-joints.

-If you buy a rear axle, I recommend an 8.8 axle from a 95+ Ford Explorer which is stronger than a Dana 44 and can be found with 3.54/3.73/4.10 gears, disk brakes, and posi (any rear axle that didn't come from under an MJ will need new leaf pads welded on)

-And get a factory shop manual too. If you buy an 87-88 truck, get the 89 shop manual. It's better than the older ones and the trucks are essentially the same.

There are a lot of little details and particulars that can give you headaches when you try to mate everything up, so when you find something, ask about it before you plunk down money at the junkyard.

Jeep on!

--Pete

Well said. 

[Pete M]

dang.  younger me really liked to type, didn't he.   thank goodness the tech still holds up.