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4x4 swap+2.5 L to 4.0L+AX-15 questions


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I have been on here for awhile but just as an observer so this is my first post and kind of an introduction ha

I'm kind of learning as I go along on most of this stuff because this is my first big project.

 

I have a '90 pioneer long bed 2wd manual trans with the 2.5L and I am getting tired of the engine and always wanted 4wd so I bought a '90 short bed eliminator 4.0L auto trans 4wd for parts (and a winter ride to save the other from one more MI winter lol) runs like a champ body is shot otherwise I would just keep both.

I also just recently got an AX-15 from an "88 YJ because I like the feel of the manual trans rather than the auto

 

I now have the 4.0L out and ready to put new seals rings etc. on it buuutt when i pulled it the engine stand fell right after with it on it and broke the alternator :doh: (luckily nothing else) so my first question is if i would be able to use the alternator from the 2.5L?

 

I originally was going to just use the trans from the eliminator and get an AX-15 later but I found one at a good price with an extra transfer case so my second question is can i use the the wiring harness from the eliminator with the AX-15 or am i going to have to get some sort of adapter?(i took everything connected to the trans with the trans)

 

I was also wondering if i would need a new computer or anything for the manual trans or does it really matter as along as its for the 4.0L?(most of my uncles on my dads side including my dad work for Chrysler/Jeep thought it just controlled the motor but they weren't completely sure about this so I just wanna make sure)

 

that's all I can think of for now but I'm sure I'll have more as I do more

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The 2.5 alternator will not work on the 4.0, totally different mounting, both location and brackets.

 

I'm a little confused on your question about the ECU........Yes, a manual and/or Automatic ECU will work on either one, but, the manual ECU has a little lower idle RPM (about 650 RPM) vs. the auto (750+ RPM) Yes, the ECU controls the engine, timing, advance, and injector pulses.

 

You'll also need to swap an auto Throttle body in for using an Automatic tranny. There are 2 plugs in the IAC for the ECU, plus the idle set screw is set for the higher RPM, and it has the bracket for the TV cable.

 

Note that the AW4 uses a separate TCU behind the knee board, under the dash.

 

If you convert from manual to auto, you'll need to swap out the dash harness.

 

The only real change you need from a BA10 to the AX15 is to make a splice of the back-up lights, the connector in the tranny housing is different and on the opposite side.

 

If I read your question right :dunno:

 

Here's a link on the conversions, it might set you a little straighter on what your asking :hmm:

 

viewtopic.php?f=9&t=12206

 

And........

 

viewtopic.php?f=2&t=13375

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I'm a little confused on your question about the ECU........Yes, a manual and/or Automatic ECU will work on either one, but, the manual ECU has a little lower idle RPM (about 650 RPM) vs. the auto (750+ RPM) Yes, the ECU controls the engine, timing, advance, and injector pulses.

 

I was wondering if i would need a different one because i want to use the the manual trans(AX-15) rather than the automatic that was with the 4.0L from the donor truck

 

You'll also need to swap an auto Throttle body in for using an Automatic tranny. There are 2 plugs in the IAC for the ECU, plus the idle set screw is set for the higher RPM, and it has the bracket for the TV cable.

 

what if it already has it? does that mean i will have to get a different one to use the manual trans(AX-15)?

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You could use the auto Throttle body for the manual, but you'll need to change out the IAC, or unplug one of the connectors, which one, I don't know off hand.

 

Yes, you could use the automatic ECU (5300-5406 or 5428) in place of the manual Ecu (5300-5407 or 5429) but your idle might be a little high.

 

One question.......we are talking about 4.0 engines here, correct, nothing to do with the 2.5, right :hmm:

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