John D
NAXJA Member # 788
- Location
- Rockford, Mi
I just finished my swap a few months ago. Check out my thread here:
http://www.naxja.org/forum/showthread.php?t=1119575
1. The wiring is NOT difficult unless you have no idea how electricity works. There is one BIG caveat to the wiring that no one mentions. If you're wiring up the OBD port, it MUST get it's power from the same wire that powers the ECU. No, just because it all comes from the same battery, does not mean you can just splice in anywhere. Splice it in within a foot or two of the ECU power. If you don't, your OBD will be wonky as all hell and you'll want to kill yourself and your whole family. Ask me how I know.
Otherwise, the wiring is very easy. The Chevy harness side is insanely simple. I'd suggest, now that I've done it, just use the stock chevy harness with the bare minimum modifications required to get it into the Jeep to start. Worry about re-working the harness once the motor and everything else have been proven. Trust me on this. It'll make your life much easier.
The Jeep firewall side of the wiring is the hardest part, only because most of your wires will be stuck together and the colors faded. Find an FSM, have it in hand. Honestly, the hardest part of this swap was dealing with Jeep wiring, and even then, it wasn't hard. I'm ****ing terrible at wiring compared to my roomies because I'm too lazy and impatient, and this still wasn't a big deal for me. Don't let everyone else scare you here. You don't need a painless harness, especially because the bulk of the wiring job is on the Jeep side.
2. Novak motor mounts suck.
3. Lots of guys say the stock A/C compressor won't fit between the motor and frame rail.
4. Don't bother with the 4.8. The 5.3 will net you between 17 and 26mpg depending on your aerodynamic profile. My heep is the poster child for all that can go wrong with aerodynamics, and I get 17-18mpg on the highway. That's pushing 35x12.5 shoes, 6.5" lift, full size roof basket with 52" light bar. On a more stockish XJ, I'd expect at least 22-23mpg from the 5.3, and my god is it fast. I drag race EVERYONE now, and I no longer do it just for the sake of being ironic. I win often.
The 6.0L I feel is overboard, but I've heard that it'll give very respectable fuel economy as well, in which case I feel like it's one of those "if it's a toss up between the 5.3 and 6.0L fo the same price, go with the 6.0L" things.
6. The AA t-case>trans adapter sucks at sealing. The trans side might seal, the middle section with the o-ring will not, nor will the t-case side with their paper gasket. Make liberal use of RTV everywhere including the o-ring. For the t-case side, you should probably just make a new gasket and RTV the hell out of it. The stock t-case studs are barely long enough to grab the nuts with a paper gasket, assuming you're using the AA mount as well. The whole thing sucks but it's doable. You may have to pull the case several times to re-seal until you get it right.
7. I'd go with a 241/241 hybrid. You can find the long input, wide bearing 241 input gear and planetary assembly from most chevy 241's. It'll drop right into your 231 case. Don't forget to swap in the WIDE BEARING on the input side if you have a wide input gear. VERY different clearances and the narrow bearing with the wide/long input gear, will have the planetaries eating the front of your case off. Also remember that the 231/241 planetaries and ring gear have two different cuts. Something like pre and post 96. The earlier were a courser cut while the later were finer. They will intermix but they will be very whiney. I used an np241c input, np231 main with sye, np241 chain and chain drive.
8. T-case shift linkage.
9. Trans linkage. Use an XJ auto shifter.
10. Radiator. The 3 row CSF scares me a bit as the tubes are very small and easy to clog. You mileage may vary. I went with a Griffin 22x19" and made it fit by cutting out the lower rad support. Keeps me VERY cold with a taurus fan behind it. Again, I'm not the right guy for this either as lots of guys have stock size xj rads doing just fine. My way worked though as well.
Feel free to toss any questions my way as well. I feel like I could do this swap the second time in a solid weekend. It's really not that bad if you aren't a tard, and/or not wildly drunk.
1. I have done two harnesses and both had OBDII port power coming in separate from the ECU without issues. I'm not sure why yours was being fussy, but good you figured it out.
2. I made my own, but it was out of necessity. Novak didn't have the mounts available when I did mine, but it wasn't hard to make them.
3. I never heard anyone say that before and mine fit fine. I have about 1/2" clearance to the frame.
4. I would definitely save a little longer and go 6.0L next time. I get about 10MPG or less, but I also drive it like I put a V8 in my Jeep. Aside of maybe one tank where you try really hard to see how high of gas mileage you can get, the MPG argument is a silly one.
6. I didn't have an issue with sealing, but I did use a liberal dose of RTV to start with.
7. In hindsight, I would definitely go with a 241C before the AA adapter/231J again.
8. I used a Novak t-case shifter and it worked really well.
9. I did this and hated it. On road, WOT and looking for 2nd gear sucks.
10. I couldn't get mine to cool either and ended up with a really expensive Be Cool radiator. It was the only solution that would work for some reason. It made me nuts because I have a buddy running a 130k mile stock radiator on his LS swap and it's fine.
Glad you got yours going and your happy.
Wrecker didn't know what it was so I got it for $5. Total hybrid case build cost me $65 or $70. Took me about an hour to assemble (my first attempt at taking apart and putting back together a case). It's really not a difficult job.
