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I am purchasing a complete 4.0, wiring harness and the complete serpentine belt setup from a 1996 grand cherokee. ( for my 1983 cherokee 4.2 ) will this setup work? any issues that I should be concerned with? thanks. Steve

I believe it will NOT bolt up to your current drive train. So grab the tranny and transfer case if you can.

i wasn't worried too much about the block. just the head and fuel injection setup. lots of wiring!

There are two things I recall that you should look out for. First, some of these 4.0L engines for the other chassis (ie Grand Cherokee) have different engine mount locations, and different bosses and holes cast into the block. Internally they will be ok, but they will not drop in to replace the 4.2L. Different chassis have different fan offsets too; I believe the 4.0L GC retains the mechanical engine-driven fan using a serpentine belt. Pretty sure it will not line up with the fan location on your 4.2L Jeep. IIRC the Wranglers are centered (like your Jeep), and others are not.

The crank stickout of a 4.2L is also different from a 4.0L, and the serpentine system won't transfer without mods at the crank pulley.

If all you want is the head, EFI and wiring, I expect that will work. Ask at the jeepstrokers site - lots of information and expertise there about compatability between the various 4.2 and 4.0L platforms. www.jeepstrokers.com

Do note the ECU is different in a manual vs auto. As all ZJ's are autos, that means its expecting there to be an AW4 behind it, not any transmission that came behind an FSJ. Though you can always get an ECU from a manual trans 4.0.

thank you tgreese and stuka for the information I was just wanting the head and fuel injection setup. But I think that I will go with the 91-95 jeep fuel injection. I already have a 93 grand cherokee wiring harness. I was hoping that the serp. belt setup would bolt up. Steve

Aw4 (transmission behind Xj's) has the same bolt pattern as the AMC V8. Not sure if your 4.2 uses the same pattern.

Might as well throw the AW4 in and get OD. Just make sure to grab the transmission controller.

BTW, the transmission harness is mostly integrated into the engine harness. But, they act independently. IIRC, they share the same throttle position signal but that's it. The fuse box also sits nicely where the durespark or vac cannister sits on the fender... at least on the later model V8 GW.

RAD designs also makes a manual controller for the AW4 as well.

http://www.radesignsproducts.com/products-1.html

89_wagon, thanks for the information about the transmission. Is the AW4 the standard OD trans for 94 grand cherokee? How strong is the AW4? would it be possible to use it and have a speedo cable for the instrument cluster? I know questions, questions! Teller, thank you for the information about the controller!

83cherokee chief wrote: ↑Wed Aug 03, 2022 3:25 pm 89_wagon, thanks for the information about the transmission. Is the AW4 the standard OD trans for 94 grand cherokee? How strong is the AW4? would it be possible to use it and have a speedo cable for the instrument cluster? I know questions, questions! Teller, thank you for the information about the controller!

The AW4 is good transmission. Several here run them in their FSJs. Its not as strong as a TH400 or something, but behind an i6 it will do what you need it to.

The speedo cable comes off the output of the transfercase, of which you can use your current transfercase. I know later 4.0's changed to a digital speedo pickup, but I can't recall the year that switch was made.

Stuka , thank you for the response. I am not familiar with Chrysler transmissions.

Stuka, looking up the transmission info for a 94 grand cherokee it says that I should have the 42RE transmission. Is this a good trans? thank you, Steve

Stuka got it right... Speedo drives off the transfer case so as long as you keep the transfer case, you're fine. There is a speed sensor on the tail of the AW4 but it's for the transmission controller. It might also be used for the Cherokee engine ECU but I don't know for sure.

I run the AW4 in my '89 GW and it does fine. But, I don't do wheeling and it's on stock suspension/tires. Just the haul the family with a few hundred pounds of camping gear through the mountains roads. If I were wheeling... definitely go with something stronger and better supported IMHO.

89_wagon. on your aw4 conversion what did you do for the shifter? in the yard I see that the shifter has 2 cables, one for throttle body for downshift, and 1 that seems to unlock the trans from park. Is this correct? Did you use the factory floor shifter? Please let me know. thank you, Steve

Fortunately, I was able to hook up the AW4 shifter to the stock linkage. So no floor shifter. I used a U-clamp to hold it all together. Kinda red-neck but it's held so far. The arm on the transmission lines up really well with the GW shifter arm, very fortunate.

Just to clarify...I clamped the Wagoneer's shift rod to the AW4's linkage rod that comes off the transmission. I'll see if I can take a pic.

89_wagon, thank you I'll keep an eye out for the pic. Steve

Something to consider that hasnt been mentioned yet. The 4L head chamber size. It maybe larger or smaller-Im not sure and it could push your compression to one extreme or the other. To high and you get detonation and too low and it runs like Crap.

rocklaurence, thank you for the heads up about the compression ratio. I believe that it will be ok. Will find out after its running!