Author Topic: 4.0l into a yj (Read 1047 times)

mrbeggins · « **on:** October 14, 2007, 03:38:56 PM »

Hey guys, can anyone tell me if it is easier to swap a 4.0l to a yj from a yj OR is it the same amount of work (wiring harness, etc.) as say using a cherokee 4.0l? Also, can a NP242 handle the same amount of work as a NP231. From what I've read, the 231 is better built. I will be running a 4.0l or 4.0l HO with auto tranny and 4:10 gears, locker in the back for sure and 36" iroks with a ford 8.8 in the rear. Thanks guys.[/b][/u]

cLAY · « **Reply #1 on:** October 14, 2007, 07:52:58 PM »

The NP242 will stand up to whatever the 4.0 will put out. I ran a 242 in my XJ with a 4.0 and 36" Iroks. Zero problems.

If you use the wiring from an XJ you can use the XJ tranny(AW4) which is virtually bullet proof and is a 4spd, vs the YJs 3spd 999. It would be best to buy a complete donor rig so you get everything you need. A custom crossmember for the tranny mount might need to be fabbed/modified. Custom driveshafts might also be needed.

BlackYJ · « **Reply #2 on:** October 15, 2007, 07:36:31 AM »

As Clay mentioned that best thing to do is get a donor vehicle. I did this swap about 1.5 years ago now. I swapped in a 94 XJ drivetrain into my 95 YJ. I took the engine, tranny, and t-case (you will need a new t-case you you will have to change the input gears), and put in my new YJ. Here is what you will need

-New motor mounts
-Lengthened front DS
-Shortened rear DS
-New fan shroud, unless going electric

As for the wiring, the firewall connectors are different between the XJs and YJs, so the guy doing my install found it easier to wire in the 2 extra cylinders than to change the bulkhead connector over on the XJ harness. This was for the underhood harness. Another thing to watch out for is that the XJ t-cases are clocked lower than the YJ cases. It has not caused me any problems but they did have to cut my t-case skid a little to allow for clearance

That about covers it

mrbeggins · « **Reply #3 on:** October 15, 2007, 08:40:08 AM »

ok, thanks for the info guys, --- lookin' for a donor.

born2jeep · « **Reply #4 on:** October 17, 2007, 11:42:06 AM »

This website is a god sent!! I would have had A LOT more troubles doing my swap without it. http://cjoffroad.com/forums/forum.asp?FORUM_ID=24

I replaced my 4.2 with a 92 cherokee 4.0, and made a hybrid of both wiring harnesses...mostly the xj one.

mrbeggins · « **Reply #5 on:** October 18, 2007, 08:31:11 AM »

Thanks for the tip born2jeep, - I checked it out and it looks like I'll be visiting it a few times.