AW4 swap questions

[AMCLOVER258]

So i found an AW4 and T case for 75 a peice here in middle town. What all would be needed or fabbed to install the aw4 behind the 4.2 block?

[eaglefreek]

I moved this from the wanted section and started a new topic for you.

[carnuck]

You need the flexplate and starter from the 4.0L XJ plus all the nuts and bolts. Rear driveshaft is different front "may" work. I hear different things.

If you plan to go EFI, decide if you can handle rewiring for Renix or HO (which is simpler) because you need the right flexplate to make it work.

[AMCLOVER258]

Im pretty firm on staying carb'd i honestly like the simplicity of it.. I may grab the aw4 and tc and have a buddy of mine to make it work and he can keep the TF and some cash...

[eaglefreek]

There are other threads here and info on the web as to what need to be done to put the AW4 behind a 258 with a carb. Unfortunately, there isn't a very precise thread for an Eagle, which I plan on doing some day.

[AMCLOVER258]

Yeah my buddy worked for chrysler for 30 years so im sure he can work it out ... The only problem getting him to help is him putting his pride aside and working on an amc. For some reason ppl within chrysler seriously despise these cars!

[carnuck]

It's because they were "forced" to become AMC repairmen when Chrysler took over. They expected the 4.0L to go away and a slant six or something Chrysler made to replace it. AMC became the red headed stepchild that the rest of the family despised.

I forgot the important part. Whether you go EFI or not, you still need the AW4 flexplate and starter to make it work.

[Nightpath]

The AW4 alone would be a headache to install for the overall lack of benefits in it's standalone form. You'd need, at the very least, the wiring harness portions and the transmission controller, which would have to be spliced out from the harness and looped into the Eagle's wiring (mainly power). Flexplate and starter to match.

To add to that you'd also need the shifter since it's a cable shift transmission in it's stock form, or buy an adapter. The shifter and it's plates will fit into the Eagle's shifter hole when you swap though, and it's not too hard to find a place to slide the cable. Would have to weld on a small piece of metal to close the gap around the shifter.

The fitment of the driveshafts is another concern. If you stick with the Eagle's 4x4 transfercase you'll need a clocking ring, as well as either get your driveshaft cut for the rear or find one that fits. The AW4 is a few inches longer than the 998, it'll compress the driveshaft all the way. Best bet would be to get the Eagle rear driveshaft cut to remove about 4 inches. The front driveshaft would need to be a few inches longer, I image a Grand Cherokee driveshaft would work.

I may add that since the AW4 would move the transfer case back a bit, it may end up hitting the butt end of the tunnel so you'd have to cut a part out for fitment, and the transmission mount would have to be custom made since they don't line up. I'd toss in a NP231 t-case.


To be absolutely honest, you'd be better off passing that by. If you want more power the headswap is a solid all around upgrade to start with. Or find a 727 (swaps directly with the 998 and is heavy duty), or regear the axles.

Why do I say this? Because I'm in the middle of a full drivetrain swap and I see it all now.

My vote? Stay away from the swap unless you have the time, money and know how.

If I were to do it over? Head swap -> fuel injection -> better gearing

[AMCLOVER258]

You my man... Have OFFICIALLY talked me out of this insane swap... guess im going with a rebuild kit in the 998!

[eaglefreek]

You my man... Have OFFICIALLY talked me out of this insane swap... guess im going with a rebuild kit in the 998!

Have it rebuilt to 999 specs and install a Transgo TF-2.

[AMCLOVER258]

Ive heard alot about those trans go kits so there def worth the purchase?

[carnuck]

If you plan to run it hard, get the bolt in sprague or buy my 999 case if you plan EFi.

Trans go isn't really needed for the Eagle 998. If you have a lockup converter (like the '99 999 case and valve body I have was designed for) get the higher speed lockup spring and put a short Chevy smallblock headbolt inside the accumulator for solid shifting. The partially electric controlled valvebody controlled when the lockup occurred or if it happened at all because you could flip a switch off.  The lockup acts like an overdrive this way.

[AMCLOVER258]

Yeah efi is just too much of a head ache im more or less bench sitting on 4.0 head or having my stock head machined and going with either the MC2100 or a brand new carter. I like the simplicity of the carb. As trans goes i may go with(thanks to nightpath) either rebuilding the 998 or 727 swap. I seem to be doing more bench sitting than acting though so my intentions keep changing as the days do..

[carnuck]

The AW4 needs a few things to work. You need to hook the TVS cable to the carb as well as a TPS (throttle position sensor) with the trans controller in it. I plan to hook mine externally to a 2100 carb on my Honcho with 304. Renix ones were supposed to go away but I see them for sale still. The harness on the trans comes up, goes through the firewall to the trans control computer under the glovebox in XJs. With that harness, you need power to the fuse by the controller.
   In SOTE we hooked up a manual controller box to the AW4 (not my idea of fun) and with the Spirit steering column that has a shifter, we went directly to the trans lever with a custom rod, using the original as a template. Even made it match the PRNDL on there. The trans lever comes off and can go back on in 4 different positions.

[AMCLOVER258]

See and that my friend, is like reading a hebrew bible to me...