XXLMJ Posted November 18, 2009 Share Posted November 18, 2009 I have an 88 MJ with a 4.0, Auto, 2wd. I just bought a 89 XJ 4.0 5 speed, 4x4. The guy told me it was a 90 and after the 2.5 hour drive i found out it was a 89 and didn't have the ax-15 trans i was hopping for. SO i still want to make my MJ a 4x4, but i don't want to waste my time with the crappy trans, i would rather keep the auto anyways since this is gona be a daily driver to and from work. My question is, will my new transfer case out of the 89 XJ bolt to my 88 auto trans in my MJ. Or will i need to find a 4x4 auto trans? Link to comment Share on other sites More sharing options...
Geonovast Posted November 18, 2009 Share Posted November 18, 2009 You will need a 4x4 trans. Link to comment Share on other sites More sharing options...
XXLMJ Posted November 18, 2009 Author Share Posted November 18, 2009 Is there any type of Auto trans that is stronger or better than others? Link to comment Share on other sites More sharing options...
Geonovast Posted November 18, 2009 Share Posted November 18, 2009 Really your only option is an AW-4. It was the only auto offered behind the 4.0 In XJ/MJs, and a 4wd one will be bolt-in in place of your 2wd one. The AW-4 is a very sturdy transmission, I wouldn't worry about strength. Link to comment Share on other sites More sharing options...
XXLMJ Posted November 18, 2009 Author Share Posted November 18, 2009 Should i buy a transfer case at the same time too. Or will the one on my 5speed work? I am unsure what kind of transfer case i actually have. Link to comment Share on other sites More sharing options...
jpnjim Posted November 19, 2009 Share Posted November 19, 2009 Best bet is the 1992+ AW4, they have stronger 23spline outputs. If you do get an '87-91(ish) AW4, it will have a 21spline output. The T-case you have now (NP231, from the Peugeot) is 21spline, and may work with the earlier 21sp AW4, but there were long & short input versions of the T-case, and I always forget what got which one. :dunno: Best bet of you want a 4x4 auto tranny is to get the later 23sp tranny & t-case combo, may even be able to trade the junky guy what you already have for a break on the pair. Link to comment Share on other sites More sharing options...
XXLMJ Posted November 19, 2009 Author Share Posted November 19, 2009 When you say a later 23sp do you mean 92+? I guess what I'm asking will a newer auto trans, bolt up? Link to comment Share on other sites More sharing options...
jpnjim Posted November 19, 2009 Share Posted November 19, 2009 When you say a later 23sp do you mean 92+?I guess what I'm asking will a newer auto trans, bolt up? Yes, and yes. Nothing really wrong with the earlier ones, but if you're gonna swap anyway, might as well go for the beefier one. Truthfully, an even better reason is newer = (hopefully) better condition. The newest 21 spline AW4 is 18 years old now. The only thing I'm not too sure about is the electrical connections, and if they changed over the years (I'm thinking they did). So you'll want research that part a little more, before you throw in the absolutely newest AW4 you can get your hands on. Link to comment Share on other sites More sharing options...
JACKED88 Posted November 19, 2009 Share Posted November 19, 2009 I need that info as well so I also try to do some research in these areas .......... What's the latest/newest AW4 that you can install behind a 88 4.0 without having to do any wiring mods? Same question but what wiring mods will need to be done to the latest AW4's in order to work properly in an older (88) MJ? When converting a 2x4 to a 4x4, will wiring have to be run from the vehicle to the trans and t/c for them to work properly? If so, from where? Link to comment Share on other sites More sharing options...
Wildman Posted November 19, 2009 Share Posted November 19, 2009 AW4's from '87-'90 Renix, 21 spline output = Separate Transmission controller. AW4's from '91-'95, 23 spline output (92+) = Separate Transmission controller. '97+ Transmission wired into the ECU. Will not work with the Renix era. With the Correct tranny controller.........a '91- '95 will plug and play with the Renix era. Link to comment Share on other sites More sharing options...
navigator Posted November 19, 2009 Share Posted November 19, 2009 One other thing to keep in mind is your 88MJ auto likely has 3.55 gears in the rear. If you take the front end from the 5spd XJ, it will likely have 3.07 which would mean you would need the rear end to have the same gears. I expect the 3.07 in an auto would be kind of weak, especially if you are going to lift and get bigger tires. I guess bottom line is if you keep the auto and go 4X4 you'll need to regear or find a front/rear out of another auto. Link to comment Share on other sites More sharing options...
JACKED88 Posted November 19, 2009 Share Posted November 19, 2009 AW4's from '87-'90 Renix, 21 spline output = Separate Transmission controller. AW4's from '91-'95, 23 spline output (92+) = Separate Transmission controller. '97+ Transmission wired into the ECU. Will not work with the Renix era. With the Correct tranny controller.........a '91- '95 will plug and play with the Renix era. OK so if your doing a 4x4 auto conversion, I assume there's a seperate controller for the 2x4 trans and if so will that controller also work for the 4x4 trans? Link to comment Share on other sites More sharing options...
XXLMJ Posted November 20, 2009 Author Share Posted November 20, 2009 OK what does a trans controller do, and were is it? And what about a speed o meter. Aren't some controlled by a cable and some by wire? Link to comment Share on other sites More sharing options...
Wildman Posted November 20, 2009 Share Posted November 20, 2009 I was just adding additional info to jpnjim post about the year difference. There is NO difference in the AW4 transmission controller between the 2wd and the 4wd, that's independent of the tranny, and makes that difference with the Transfer case (Manual engagement) :brows: The transmission controller sends and receives signals from the ECU for shifting, braking, acceleration, via controlling the solenoids in the tranny. The tranny controller is found on the back side of the knee panel, about under the radio/heater controls, held in place with a Velcro strip. The speedo from the '91-'95 AW4 is electric operated, and the entire quill is changed out with the mechanical controlled quill from the Renix era, direct change out. Plus, the speedo gear needs to be changed out with what axle ratio your running (including tire size) navigator points out a Very Important fact about the axles :thumbsup: Other notes to consider when swapping an AW4 in place of a manual, including a transfer case, is the length of the speedo cable, Adding the TV (Throttle Valve) cable bracket to the throttle body (Cherokee just schooled me that one) and changing the IAC from a manual to the automatic control (Different idle RPM's) and the ECU to an auto control unit. Plus changing the brake pedal, unless you want 2 brake pedals, one right and one left........and I'm sure I'm forgetting a few small items........like the shifter lock out in the steering column, Adding the tranny cooler, and so on. Link to comment Share on other sites More sharing options...
XXLMJ Posted November 20, 2009 Author Share Posted November 20, 2009 I'm replacing a 4.0 in my MJ that is already an auto, but the motor I'm putting in it is out of a XJ that was a 5speed. I'm also converting my MJ to 4x4, Will my factory ECU in the MJ work? Link to comment Share on other sites More sharing options...
jpnjim Posted November 20, 2009 Share Posted November 20, 2009 AW4's from '87-'90 Renix, 21 spline output = Separate Transmission controller. AW4's from '91-'95, 23 spline output (92+) = Separate Transmission controller. '97+ Transmission wired into the ECU. Will not work with the Renix era. With the Correct tranny controller.........a '91- '95 will plug and play with the Renix era. I posted the change from 21 to 23sp as being 1991ish for 21 spline, and 1992 for 23spline since there seemed to have been some lag between when they tried to make the upgrade, and when they were actually were able to put the upgrade in place. A few years back I had found the upgrade listed in the 1991 Factory Data book (along with a change in the O/D ratio), and posted it in a thread somewhere (maybe JU). Feedback & experience from other posters in that thread suggested the upgrade didn't happen exactly as the 1991 model year was rolling out. I've never pulled the T-case off of a 91' AW4 to check, but giving the benefit of the doubt to the guys who posted in that thread, I always figured 1992 was a safer bet to get the upgraded output shaft. YMMV, and since the literature does say 1991 for the upgrade, I'm not disputing your info, just explaining why I posted 1992. :D Link to comment Share on other sites More sharing options...
jpnjim Posted November 20, 2009 Share Posted November 20, 2009 A few years back I had found the upgrade listed in the 1991 Factory Data book (along with a change in the O/D ratio), and posted it in a thread somewhere (maybe JU). Feedback & experience from other posters in that thread suggested the upgrade didn't happen exactly as the 1991 model year was rolling out. I've never pulled the T-case off of a 91' AW4 to check Not sure if this is the thread I was thinking about, but it might be: http://www.pirate4x4.com/forum/showthread.php?t=174770 Link to comment Share on other sites More sharing options...
Wildman Posted November 20, 2009 Share Posted November 20, 2009 A few years back I had found the upgrade listed in the 1991 Factory Data book (along with a change in the O/D ratio), and posted it in a thread somewhere (maybe JU). Feedback & experience from other posters in that thread suggested the upgrade didn't happen exactly as the 1991 model year was rolling out. I've never pulled the T-case off of a 91' AW4 to check Not sure if this is the thread I was thinking about, but it might be: http://www.pirate4x4.com/forum/showthread.php?t=174770 I'll agree with you on that one, that's like saying at some point ( I'm thinking after November of '88) all 5 speed manuals were AX5's in the '89 model year. I also left out the '96 model year, cause I couldn't remember off hand if they changed in the '96 or '97 model year to the newer ECU controlled trannys. So I played that one safe, knowing that the '96 model year went to the OBD II system. I was just adding info I know to you original post, on what years could be donors to our Renix era units :D Link to comment Share on other sites More sharing options...
jpnjim Posted November 20, 2009 Share Posted November 20, 2009 A few years back I had found the upgrade listed in the 1991 Factory Data book (along with a change in the O/D ratio), and posted it in a thread somewhere (maybe JU). Feedback & experience from other posters in that thread suggested the upgrade didn't happen exactly as the 1991 model year was rolling out. I've never pulled the T-case off of a 91' AW4 to check Not sure if this is the thread I was thinking about, but it might be: http://www.pirate4x4.com/forum/showthread.php?t=174770 I'll agree with you on that one, that's like saying at some point ( I'm thinking after November of '88) all 5 speed manuals were AX5's in the '89 model year. I also left out the '96 model year, cause I couldn't remember off hand if they changed in the '96 or '97 model year to the newer ECU controlled trannys. So I played that one safe, knowing that the '96 model year went to the OBD II system. I was just adding info I know to you original post, on what years could be donors to our Renix era units :D :cheers: & I almost always leave 1996's out of things too. :yes: (someday I'll end up buying one just to rip it apart and answer all the questions I have. :nuts: ) Link to comment Share on other sites More sharing options...
Wildman Posted November 20, 2009 Share Posted November 20, 2009 I'm replacing a 4.0 in my MJ that is already an auto, but the motor I'm putting in it is out of a XJ that was a 5speed. I'm also converting my MJ to 4x4, Will my factory ECU in the MJ work? Are both engines Renix era??? Is the engine your swapping from a XJ Renix era engine. Other wise, you'll have issues with the intake manifold and the throttle body. If your swapping the 4.0 Renix from both, you only need to change over the throttle body, it will give you the TV bracket and the automatic IAC. Also, you'll need to take the flywheel off the manual engine and install the Flex plate from the automatic. Your OEM ECU will work with any AW4 that is from the '87-95 years were talking about above, you still have the transmission controller in place. I think your original question has been answered above, you can not use a 2wd auto tranny with a transfer case, it must be a 4wd transmission to bolt a transfer case to. Link to comment Share on other sites More sharing options...
Wildman Posted November 20, 2009 Share Posted November 20, 2009 & I almost always leave 1996's out of things too. :yes:(someday I'll end up buying one just to rip it apart and answer all the questions I have. :nuts: ) Well stop on by........I got a '96 Country XJ just waiting to be tore into :brows: Link to comment Share on other sites More sharing options...
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