Information for replacing aw4 with NSG-370 6 speed

Earlier this year i converted my 2001 automatic 4wd XJ to a 6 speed manual (the NSG-370 from 05-06 wrangler). I figured there might be a few people that would like some info about doing this kind of swap. So, I'm going to list a few things that worked and some things that i had trouble with.

First, parts that i used for the swap;

05 NSG-370 4wd transmission (came with shifter but needed new knob) If i did it again it would get a 06 trans because the reverse lever internally bends and is hard to get in sometimes
and sometimes 1st gear will jump out. In 06 they fixed those two things.
Centerforce flywheel for 2001 Cherokee (nv3550)
LUK gold series clutch for 2001 Cherokee (nv3550)
06 wrangler Crank Position Sensor and Reverse light repair wiring harness
Clutch and brake pedal assembly from salvage yard. (found on car-part.com)
Mopar Clutch interlock switch
Pre-bled master and slave cylinder (oreilly's)
2001 manual ECM from salvage yard. (found on car-part.com)
Advance adapters slip yoke eliminator
Driveshafts from two different grand cherokee's (local pick-n-pull)
shift boot, trim bezel, and transmission tunnel boot (jeeps-r-us)
1" Transfer case crossmember drop brackets
06 wrangler transmission mount

Everything was pretty straight forward with removing the aw-4 and all the stuff that goes with it.
The first problem i ran into was bolts for the flywheel and clutch, MAKE SURE YOU ORDER THESE BOLTS BEFORE YOU START YOUR SWAP. I didn't think about this ahead of time and when i went to my local stores looking, not a single place could even get them. I ended up using grade 8 hardware, which should be fine but i would have rather of had the proper bolts.
The next problem, Crank position sensor (CPS) for the wrangle sticks out a couple of inches and hits the transmission tunnel. the nsg-370 moves the CPS over to the passenger side. I had to carefully trim the cps down, bend the copper tabs forward, solder wires onto them and heatshrink to seal it back up.
Another problem, the nsg-370 clocks the transfer case to a more level position under the jeep. So now, when i tried to jack the transmission/ transfer case up to put the crossmember on. the transfer case was hitting the body. I had a 1" transfer case crossmember lowering kit laying around, so i put that on. Then, the crossmember didn't line up perfectly with the new transmission mounting location once it was bolted up to the manual transmission mounts on the jeep frame. I drilled new holes in the crossmember to get it all lined up and it was all good.
Fourth problem, transfer case shift linkage then needed to be modified to get it hooked back up and working properly. The new transmission is about 1" shorter than the automatic, so i had to shorten the rear shift linkage rod 1" to get it working.
Now, everything else went pretty smooth. I just had to tap into the auto trans wiring harness to hook up the reverse light switch and the clutch interlock (which had to activate the neutral safety switch). Got all that wired up and put in the manual ECM.
I also had to do a good bit of work on the console to make the shifter look factory. I took the automatic shifter and cut out that piece to fit the shifter boot into it. Then, I had to cut the shifter down and weld it back together to get it where i wanted it.
Last but not least, I had found two driveshafts at the pick-n-pull that were the right length. One is a front shaft from a 97 awd grand cherokee that's shorter (it went in as my front shaft), and the other was also a front shaft from a newer grand cherokee (not sure of the year but the front shaft is longer and i was able to use it for my rear shaft, since i have the SYE).
But all in all when i was finished, It looked like it was meant to be there and no check engine lights! I love the way it pulls and you can lug it around at 1000-1500 rpm. That lower first gear is nice for off-roading.
I will try post up some pics sometime soon. I hope someone out there benefits from some of this info, when i was doing my swap i could not find anyone that had already done this. That's why i figured i would write some of the things down that troubled me. Obviously, i didn't go into detail about how i did each and every step because it took me two weeks to get all this done (in the evenings) and i don't have enough time to write each thing down. If anyone wants to know more about a specific thing i did, just ask and i will be glad to go into more detail.

Ive been wanting to do this, thanks for the info

Do you have a total cost for everything?

Good write up! I might look into this.

I probably have $2500 in everything. I bought a lot of the more expensive stuff to do mine. You could probably shave a good bit off of that if you could luck up and find some of this stuff at the local pick-n-pull. For example, i went to the dealership for stuff like the shift knob, CPS, wire harness repair kit, and clutch interlock switch. Thats stuff can be gotten cheaper at the local parts store along with the clutch and flywheel which I ordered the more expensive Centerforce and LUK. The clutch and brake pedal assembly was no easy task to find. You could probably find one of those cheaper if you had some good pick-n-pull's to go hunt around in. Where i live the selections are limited.
The only real downside to the nsg-370 is the bellhousing is a part of the transmission so it will only bolt up to a 4.0L. and some say its slightly weaker than the nv3550. But, i love the 6 gears, deeper first gear, and the shifter feels awesome (not all loose like a nv3550).

Also, the ECM. I bought a ECM out of a manual cherokee of the same year. You don't really have to do this from what i've read but if you don't, you will get a bunch trouble codes and a permanent Check engine light. Although i can tell a difference between to two computers. The manual seems to be a bit more touchy from idle to 1000 rpm. with my auto i could slowly raise my rpms up by just touching the throttle a little bit and now with the manual it seems like as soon as i touch the throttle it jumps up to 1000 rpm. kind of weird

Timster said:

The manual seems to be a bit more touchy from idle to 1000 rpm. with my auto i could slowly raise my rpms up by just touching the throttle a little bit and now with the manual it seems like as soon as i touch the throttle it jumps up to 1000 rpm. kind of weird

Click to expand...

there's a lot more rotating weight and drag with the automatic, even in neutral. the front pump is still generating a lot of psi. this could be why the manual trans makes it seem like it jumps

I bet your right, i hadn't even thought about the pressure the auto trans was building. That's probably the difference. So, there probably isn't any difference in the tuning between auto and manual computers

Good stuff, Tim[ster].

How's the 6spd compare with the AX15 in terms of gearing, as well as strength?

The difference in gearing between the two.

AX15 Input Torque Rating: 300 ft. lbs.

1st 3.83
2nd 2.33
3rd 1.44
4th 1.00
5th 0.79
Rev 4.22

NSG-370 Mfg. Input Torque Rating: 272 ft. lbs.

1st 4.46
2nd 2.61
3rd 1.72
4th 1.25
5th 1.00
6th 0.84
Rev 4.06

Better granny, turn a little higher RPMs on the freeway (not necessarily bad.) Not sure how I feel about a 10% lower torque rating, though. If I ever build a stroker, that's a concern.

I bet that 6speed is still pretty good with 3.55's and 33's! I loved my AX-15, 31's, and 3.55's.

Right now i'm only on 31's with 3.55's and it definitely has room to grow. I feel like the gearing would be fine for 32's definitely and probably 33's. right now i can run 35 mph in sixth gear at about 1100-1200 rpm and still accelerate without it bogging.

Wow I didn't think first was that low in the 370. Now I really want one