[JrMechanic]

Anyone doing this swap, refer to my thread as well.

To make things simpler, there is no need to remove the tail cone, or anything on the rear of the case for that matter. All you have to remove is the front output yoke, and ONE snap ring from the input shaft. If you're thrifty, you don't even need snap ring pliers.

[Mxlt]

Would a 99 WJ NP242 be good to replace the NP249 on a 5.9 ZJ by swaping a few parts?

TIA

[Eldoradoman]

you'd probably want the 242HD version from a WJ to handle the 5.9's torque.

[ghcoe]

I believe the only difference is there are more sun gears on the HD. I would think that the 242 would have plenty of strength for the 360. I believe the only reason they did not have the 424 behind the 5.2 was not because they were weak but, because the axles were a little light for the V8.

[Eldoradoman]

Originally Posted by ghcoe

I believe the only difference is there are more sun gears on the HD. I would think that the 242 would have plenty of strength for the 360. I believe the only reason they did not have the 424 behind the 5.2 was not because they were weak but, because the axles were a little light for the V8.

I thought they didn't put the 242 behind V8 ZJ's because the rear tires spin so easy (especially with 3.73's) since the rear end is light. Front axle is the same for V8/I6 ZJ's (D30), only rear was different, and that wouldn't matter if you have a different transfer case. Or are you talking about the input/output shafts?

[Mxlt]

For what I've read I guess the NV (NP) 242 from a 99 WJ is strong enough for the 5.9. My question is more related to input/outpu shafts being compatible and by swaping them from 249 to 242. I've seen several post about swaping them but only with earlier 242's (98 --older).

Thanks

[ghcoe]

Originally Posted by Eldoradoman

I thought they didn't put the 242 behind V8 ZJ's because the rear tires spin so easy (especially with 3.73's) since the rear end is light. Front axle is the same for V8/I6 ZJ's (D30), only rear was different, and that wouldn't matter if you have a different transfer case. Or are you talking about the input/output shafts?

I believe that the rear axle is the same for both I6 and V8 (35). Unless it came with the optional aluminum cased 44 which from what I have read were not the best. 3.73 gears were for pulling trailers. Pulling a 6000lb trailer with a 35 with 3.73 will most likely damage something pretty quick. With two axles pulling it takes some of the load from the rear axle. When I had the transfer cases apart I remember thinking that the 242 looked stronger internally. The chain was wider.

Originally Posted by Mxlt

For what I've read I guess the NV (NP) 242 from a 99 WJ is strong enough for the 5.9. My question is more related to input/outpu shafts being compatible and by swaping them from 249 to 242. I've seen several post about swaping them but only with earlier 242's (98 --older).
Thanks

It is a good idea to go ahead and get the drive shafts from the donor vehicle, that way if they are different you can have the shaft made with the right ends. When I did my swap I had to convert the 249 front case half so I could use it with the 242 rear case half. Was not too bad, but I did have to change the front yolk because the chain is different. Luckily it bolted directly to the front drive shaft with no problem. The rear shaft on the 249 was a internal slip and the newer 242 was a external slip. Luckily I got the rear and front shafts with the deal. Had to have the drive shaft shortened any way so I just gave him both shafts and he swapped ends when he shortened it.

George.

[Eldoradoman]

Originally Posted by ghcoe

I believe that the rear axle is the same for both I6 and V8 (35). Unless it came with the optional aluminum cased 44 which from what I have read were not the best. 3.73 gears were for pulling trailers. Pulling a 6000lb trailer with a 35 with 3.73 will most likely damage something pretty quick. With two axles pulling it takes some of the load from the rear axle. When I had the transfer cases apart I remember thinking that the 242 looked stronger internally. The chain was wider.

Okay, quick lesson; 96-98 V8 ZJ's all came with D44A rear axle, 93-95 V8 ZJ's had D35 rear. So a 5.9 would definitely have D44A, and 3.73's were on every 5.9 I've seen so far as the trailer towing package is almost always equipped on them.

Anybody migrate a WJ 242 with a ZJ 249 successfully?

[JrMechanic]

If you like having no speedometer, you can use a WJ 242. Otherwise, get a 242 from a ZJ or XJ.

Jeep didn't put the 242 in the 5.9L Limiteds because the 249 is the "best" transfer case Jeep had to offer at the time. For the average person who doesn't know much about vehicles, the 249 is far superior to the 242, not to mention it is slightly stronger.

Strength isn't an issue though. The 242 is still rated to somewhere around 1,400 ft/lbs of torque.

[ErikTheRad]

Yikes, thats a good point about the rear-end possibly not being strong enough on the Dana 35's to go 2wd and pulling a load. I never even thought about it. I have a 93 ZJ 5.2 w/ the 249, which I'm pretty sure has a Dana 35 rear-end. I just pulled the 231 out of my donor Jeep which I plan to eventually put in my 93. So in 2wd and pulling my boat or my pop-up tent trailer, both of which weigh less than 3,000 pounds, am I going to overload my Dana 35?

[Mxlt]

Originally Posted by JrMechanic

If you like having no speedometer, you can use a WJ 242. Otherwise, get a 242 from a ZJ or XJ.

I was afraid of that . So, there is no way of adapting that part (speedometer) on the 242, right?

I guess I'll have keep looking for a 242 from ZJ/XJ's. WJ 242 was cheap and locally available.

Thanks a lot to everyone for sharing your knowledge

[JrMechanic]

Originally Posted by ErikTheRad

Yikes, thats a good point about the rear-end possibly not being strong enough on the Dana 35's to go 2wd and pulling a load. I never even thought about it. I have a 93 ZJ 5.2 w/ the 249, which I'm pretty sure has a Dana 35 rear-end. I just pulled the 231 out of my donor Jeep which I plan to eventually put in my 93. So in 2wd and pulling my boat or my pop-up tent trailer, both of which weigh less than 3,000 pounds, am I going to overload my Dana 35?

NO. It might be working a little harder, but you're not going to overload it. Jeep sold plenty of 2wd ZJ's.

[EMTimZJ]

Originally Posted by JrMechanic

NO. It might be working a little harder, but you're not going to overload it. Jeep sold plenty of 2wd ZJ's.

Exactly, a 93-95 2wd ZJ with the 5.2L would have had the D35 out back. In stock form, the axle works/ed fine.

[RedlegWJ]

Originally Posted by Mxlt

I was afraid of that . So, there is no way of adapting that part (speedometer) on the 242, right?

I guess I'll have keep looking for a 242 from ZJ/XJ's. WJ 242 was cheap and locally available.

Thanks a lot to everyone for sharing your knowledge

Input shaft is longer on a WJ. The gear on the shaft uses the wider chain on a WJ, so you'd have to research pressing on the wider WJ gear onto your shorter ZJ shaft if you wanted to swap it in for it's length and the speedo gear. I believe they use a different rear output seal too, so the cone would have to come with the shaft anyway (a ZJ 231 cone will bolt to the 242 case, the WJ cone even has a casting detent in the same spot as the speedo gear on the 231) allowing for the speedo gear to mount up. Then, after all that, your drive shaft will need to be lengthened.

[ghcoe]

Originally Posted by ErikTheRad

Yikes, thats a good point about the rear-end possibly not being strong enough on the Dana 35's to go 2wd and pulling a load. I never even thought about it. I have a 93 ZJ 5.2 w/ the 249, which I'm pretty sure has a Dana 35 rear-end. I just pulled the 231 out of my donor Jeep which I plan to eventually put in my 93. So in 2wd and pulling my boat or my pop-up tent trailer, both of which weigh less than 3,000 pounds, am I going to overload my Dana 35?

I have blown a 44 in a scout while in two wheel drive low range without the front axle engaged (twin stick). You have to ask yourself why would jeep not offer the 242, which was such a popular option for the I6 jeeps, behind a V8? If you do not "bang" on it you should be fine.