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Unread 02-20-2015, 08:53 AM   #1
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1999 TJ Wrangler 
Join Date: Sep 2012
Location: springfield, pa
Posts: 414
full 4.0 swap from 98 tj questions.

so I recently picked up a 00 wj from a guy for $600. was told it overheated once but I think this guy was full of *****. im going to swap the longblock at least. a guy that I have recently bought parts from for my last tj still has a 98 sahara just sitting there with a perfectly good drivetrain. bone stock and only 120k on it. I made him an offer of $400 for the whole drivetrain and he said yes. so I will be picking up the motor, trans and tcase within the next month when it warms up a little.

so to my questions and concerns.

1. can I use the trans from the 98 tj (32rh) I believe with out replacing the pcm for the motor?

2. if I have to replace the pcm, im guessing that will cause me to have to convert to a distributor for the motor?

3. I plan on grabbing the whole shifter for the tcase from the tj, do I need to modify the shifter bracket like I was seeing in the faq section 231 swap write-up?

4. I plan on nabbing the entire engine harness too. is there anything I should be making sure I grab while im at it? anything the is crucial to this swap?

5. what has to be done to the rear driveshaft? planning on an sye eventually but for now just looking to get it on the road so lift everything else will have to wait.

6. when I eventually get my tj back from the police (accident under investigation, drunk driver that hit me killed his passenger) I plan on using the ax15 trans in this wj. is this a difficult swap? I haven't been able to find a write-up for it.

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Unread 02-20-2015, 02:21 PM   #2
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2000 WJ 
Join Date: Jun 2013
Location: , NV
Posts: 982
The WJ is kind of unique in the jeep lineup I think you will have a really hard time swapping anything that is not from a WJ into it.
I am no a pro though so maybe someone else knows more but I don't think its going to work.
Would be better off trying to build on something the parts are for then trying to stuff them in a very picky WJ just my opinion.
2000 Jeep grand Cherokee
I6, selectrac, dana 30 front 44a rear
Stock not lifted.
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Unread 02-20-2015, 02:44 PM   #3
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Join Date: Sep 2012
Location: Groves, TX
Posts: 393
Don't know about where you live but most states require that the engine being swapped be the same year or newer than vehicle it is going into. As for a 5 spd swap; search for member Agitated Pancake (I think that's his user name). He has successfully swapped an manual in his WJ. He is on here and Pirate; I think his build is on Pirate though. It is definitely NOT plug and play as this vehicle was never offered from the factory with anything other than a auto. All this being said, where there is a will, there is a way. I really think though you would be better off finding a donor engine out of a WJ and sticking with your auto. Just my .02 Good Luck!
-Carpe Diem Phil 1:20
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Unread 02-20-2015, 06:57 PM   #4
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1998 ZJ 
Join Date: Nov 2012
Location: Broken Arrow, OK
Posts: 587
Main problems I see is I don't believe the 98 block is drilled to accept your WJ engine support brackets, and the head doesn't have the bosses to bolt down the coil pack.

As for the trans, it's shorter than the 42RE you have now, so it will position your transfer case further forward requiring a shorter front driveshaft, and a longer rear driveshaft.

As for eliminating the coil pack and going to a regular distributor, yes, you'll need a different PCM, and make a few wiring modifications.

Your easiest solution is to use the $400 and get a used 4.0 that will fit your WJ.

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Unread 02-20-2015, 09:38 PM   #5
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2001 WJ 
Join Date: May 2013
Location: Longmont, CO
Posts: 418
The blocks are totally different. I made this mistake before. The engine mounts bosses are different and the accessories mount different too, ie alternator, compressor etc. You would need an engine from a 2000-06 TJ, 99-2000 WJ or 2001-04 WJ(Swapping sensors)
2001 GC Laredo 4x4 Black
New 4.0 @ 149
2001 GC Laredo 4x4 Silver
New 4.0 @ 165
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