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So I plan on doing the 4wd conversion to my 1989 2wd automatic 4.0L MJ. I obviously want the cheapest route and don't mind the work needed. I guess my question is, if i found another xj within the years 87-90 (renix) does everything swap right in? besides the rear driveshaft (I know that would have to be re-sized).

 

I also have an automatic tranny right now and keeping it would be less costly and less work than getting a manual trans but would my ax4 be a good match up for a transfer case? Or would I have to swap the trans from a donor with a 4x4 auto?

 

This is my first big project for me so help would be appreciated! :thumbsup:

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Correct, 2wd transmissions cannot just bolt up to a transfercase.

 

Just to avoid some confusion, you have an AW-4, not an AX-4. The AX-4 is a 4 speed manual transmission used behind the 2.5 and 2.8.

 

If you picked up an entire Renix 4.0 5 speed XJ, converting to a 5 speed wouldn't be that much extra work, if you really want the manual. Really the worst issue with that is dealing with axle ratios. You'd need to either install the XJ's rear axle, which involves welding on spring perches, or find a separate 3.55 D30 for the front, which is going to be the most ideal situation.

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Dads MJ is current a 4.0/AW-4 2wd we are just going to swap the 2wd AW-4 for a 4wd AW-4 with a 242 bolted on it.

 

The least we would need to do is swap front axle, swap trannys, shorten or replace rear drive shaft, get a front drive shaft. (the gears will need to match in the front and rear axles)

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If you've never done a transmission before, it's going to be a great pain in the ....learning experience for you.

 

As for setting up a clutch, you'll need to bolt in the manual pedals, drill a hole in the firewall for the master (should be outlined and dimpled for you). No linkages, clutch is hydraulic.

 

If you're on a tight budget and timetable, sticking with an auto will be your best bet. However, if you decide you want to go the 5 speed route, we can walk you through it.

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i did this to my jeep. it was 2wd originally. had to swap trannys. the 2wd output shaft is too long and you can't cut it (i already measured). just remember that pre-91 AW-4 have a 21 spline output and 91 and newer have a 23 spline. i found an 88 xj on craigslist with no motor for 200 bucks. took the front anxle, trans and t case and it was a direct swap. when looking for a D30 make sure it's a the one-piece long axle. it's a lot stronger and is a high pinion. so if you can find a wrecked 4wd xj or mj, it makes it a lot easier

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Okay so I have a 2wd aw-4 and I'm wondering if i can change the output shaft to the 4wd trans. To my knowledge that is the only difference between 2wd and 4wd trans. Or do i have to get the 4wd trans...

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Okay because i know old transmissions had bolt on output shafts so i thought they could be changed. Also, is the front suspension all the same? Is there any other modifications i need to make to the front

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Okay because i know old transmissions had bolt on output shafts so i thought they could be changed. Also, is the front suspension all the same? Is there any other modifications i need to make to the front

 

a dana 30 axle will bolt up with no modifications. just remove the dead axle and bolt up the d30. and as for your trans, you can put a 4wd short shaft in a 2wd trans but it would cost more than finding a used 4wd trans

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