I've got a larger TJ Rubicon 4:1 transfer case that I'm going to stick into my YJ very soon - like next weekend. It will require tunnel mods, which I've never done before. I'm looking for some help!
My old AX5/NP231 is out of the Jeep. And I'm sticking in an AX15/Rubicon case using an Advanced Adapters Kit and an AX5 bell housing.
Rubicon NV241OR Transfer Case:
I currently have a full flat tummy tuck, and would like to keep my skid plate as high as possible. Existing with NP231:
I'm pretty certain that I won't be able to keep my skid plate flat with the frame rails with the Rubicon Tcase, but I also don't want to go back to a 3" drop. Existing with NP231:
The front input of the Rubicon Tcase is about 1.5" taller than the NP231:
I am willing to cut the tub to get clearance, but that area of the tub is not easy to modify. There's a crossmember running right in that area that supports the tub/tunnel/front seat bolts.
Here's a shot with that crossmember sketched in:
And you can see it here (this is just a picture I found on the web):
I'm willing Cutting the tub for more clearance, but removing the middle section of that crossmember around the tunnel seems like a bad idea.
I'd like to keep the tunnel as "stock" as possible. I want to keep the fab to a minimum, while doing it right and strong.
Option 1, which I don't particular like, is just to do a bump out behind the shifter.
Option 2 - just reshape the tunnel over the shifter area, so it blends easier. I think this will look the best, but would require a little more work/tub cutting. I've got it drawn out of scale - I'll need to be 1" to 1.5" over the existing tunnel.
I'd cut it something like this, and also reuse the existing shifter cover plate.:
1) The old transmission/Tcase are out, so the next step is to install the AX15 and Rubicon Case and see where to cut and how much.
2) I need to remove the seats and console.
3) I'll try to cutoff the existing tunnel in one piece, raise it as necessary, and fill in the sides and back with overlapping new steel that should be about 1" to 1.5" tall.
4) I'll make a cardboard template and fill in the front of the tunnel via Option 2.
5) Crossmember - most of it will remain in place since I am just raising the existing tunnel. I'll make cardboard templates and form/weld/fab some brackets to connect the cut crossmember on both the passenger and driver's side. This should keep it almost as strong as stock.
If you can tell what I'm proposing, how does this sound? I've never modded a tunnel before, so any feedback would be much appreciated!