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89 Comanche Eliminator 2wd to 4wd questions


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I know this topic has been covered a bunch and I have gathered tons of information, but still have a few questions.

 

I have a 1989 Jeep Comanche Eliminator 4.0L, automatic with the AW4, with a Dana 35 3.55 rear axle, 2wd model.  It's 6ft SWB version.

 

First question, was the Eliminator in 89 even offered in 4wd ever?

 

I plan to do the NP231 with another AW4.  I know I need to get those to match and pre-91 are all 21 spline and after are 23 spline.  I have a newer XJ matching set that should bolt right up to the back of the 4.0L.

 

I also know I need a front axle.  After research here, I'm thinking a late 90's XJ Dana 30 front axle that is the solid single piece without the vacuum stuff.

 

From what I have read this type of axle will bolt right up with no rigging or modifying needed?

 

I know I will then need a front drive shaft, there are tons of them available, part number 53005542.

 

I also know I will need a new rear drive shaft, the one I would need is part number 53004670 and those are not easy to find so far, still looking.  I know I can get others and cut them down and/or get a custom one made to the correct length, not a problem.

 

So the next question is since I have the non vacuum front axle and the newer style NP231/AW4, I believe my speedometer is the mechanical kind in 1989 and that combo will want an electrical speedometer, how do others fix this?  My dash is working great with the original vehicle mileage, was hoping to not have to change it out.

 

Also, with the newer combo transmission/transfer case should I use the same TCU transmission computer or do I need to have a newer one?

 

Should I keep the electrical harness and connector from my 2wd AW4 to use on the newer 4wd AW4?

 

Will I have issues with the reverse lights working with my system and the newer NP231/AW4?

 

Is there anything else I'm missing?

 

Thanks for the help!  I gathered all my information so far from this forum and appreciate the help!

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I forgot one thing, how to get the 4wd light working properly when you go with a one piece axle and remove the vacuum stuff. I know in 89 the axle had a line to a vacuum switch which triggered the 4wd light. I assume the light is still in my cluster even though it came with 2wd, but not sure how to trigger it to come on.

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Good to see someone do some thorough research and asking informed questions instead of bombarding the forum with 2419 clueless questions as is usually the norm. :thumbsup:  I've answered what I can below in RED.

I know this topic has been covered a bunch and I have gathered tons of information, but still have a few questions.

 

I have a 1989 Jeep Comanche Eliminator 4.0L, automatic with the AW4, with a Dana 35 3.55 rear axle, 2wd model.  It's 6ft SWB version.

 

First question, was the Eliminator in 89 even offered in 4wd ever? Pretty sure 1991 was the first 4WD Elim, also the first LWB Elim.

 

I plan to do the NP231 with another AW4.  I know I need to get those to match and pre-91 are all 21 spline and after are 23 spline.  I have a newer XJ matching set that should bolt right up to the back of the 4.0L. Grab the TCU for the XJ set also as the pinouts changed in 1991.

 

I also know I need a front axle.  After research here, I'm thinking a late 90's XJ Dana 30 front axle that is the solid single piece without the vacuum stuff. Si.

 

From what I have read this type of axle will bolt right up with no rigging or modifying needed? Yes it should.

 

I know I will then need a front drive shaft, there are tons of them available, part number 53005542. Correct p/n for 4.0 w. auto.

 

I also know I will need a new rear drive shaft, the one I would need is part number 53004670 and those are not easy to find so far, still looking.  I know I can get others and cut them down and/or get a custom one made to the correct length, not a problem. Get a new one made. The 2WD shafts have a rubber sheath which may or may not cause balancing problems after shortening. Got mine form Ron Wood.

 

So the next question is since I have the non vacuum front axle and the newer style NP231/AW4, I believe my speedometer is the mechanical kind in 1989 and that combo will want an electrical speedometer, how do others fix this?  My dash is working great with the original vehicle mileage, was hoping to not have to change it out. Your mechanical speedo cable should transfer over to the new tcase if you transfer the speedo gear and mechanical speed sensor from your old AW4 tailshaft.

 

Also, with the newer combo transmission/transfer case should I use the same TCU transmission computer or do I need to have a newer one? One or the other TCUs will work keeping your original harness. W/o knowing the pinout differences, I don't know for sure, but I'd bet $$ that your old TCU with the original harness will be fine for the new AW4.

 

Should I keep the electrical harness and connector from my 2wd AW4 to use on the newer 4wd AW4? ^^

 

Will I have issues with the reverse lights working with my system and the newer NP231/AW4? You should not - the NSS connectors are the same.

 

Is there anything else I'm missing? Perhaps - I'm sure others will chime in.

 

Thanks for the help!  I gathered all my information so far from this forum and appreciate the help!

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Thanks everyone, great info!

 

What about the 4wd indicator light, which isn't that important, but curious. I assume I can wire up something on transfer case to the wires on firewall for dash light?

I am curious as well. I just run without it. Conversion post in the link in my sig

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Thanks everyone, great info!

 

What about the 4wd indicator light, which isn't that important, but curious. I assume I can wire up something on transfer case to the wires on firewall for dash light?

I am curious as well. I just run without it. Conversion post in the link in my sig

I have 91 this was one of the few things it wasn't prewired for. The harness from the 96 aw4/231 combo had the plug wired for it (the two extra wires in the trans plug) I bought a new indicator switch which is on the tcase plugged it up ran two wires from trans plug under hood to dash and boom works like a charm. I have 91 wiring fsm if needed.

If you don't have existing wiring on harness just find indicator switch at tcase and run wires directly to dash.

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So my friend also has a good AX15 to hook up to the NP231 and I'm going back and forth on staying with automatic or going to manual.

 

So if I was to go to manual, these are the additional steps I have found during my research, does anyone know of anything I missed?

 

  • The front/rear drive shaft will be different sizes with a manual
  • Same thing with the spline count, get a matching AX15 to your NP231, also better with newer model with external slave cylinder
  • Find a new pedal assembly that includes a clutch from a Comanche or Cherokee from 84-90, should bolt right up?
  • Need new clutch cylinder, should have dimples on the firewall where it should mount
  • Will have to short two pins in the automatic transmission connector to disable neutral safety switch
  • Have to hook up the reverse lights somehow to the manual?
  • Do the same with the speedometer cable as above
  • Need a different cross member for an AX15, one from a 2wd or 4wd should work?  You then have to move it's location, but there should be a separate set of holes or dimples to thread new mounting holes on the frame?
  • There is some other bracket people talk about that mounts to the AX15 and then to the cross member?
  • I would have to get a new shift plate for the transmission hump because the automatic one will not work?
  • Same 4wd shifter and plate as the automatic?

 

This seems to complicate the job, but not too much...

 

I'm going to start by putting in the sold one piece non vaccum Dana 30 front axle because that part is shared between both projects.  Then probably drive for awhile and decide.

 

Thanks for the help!

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I found this 93 Cherokee, 5 speed, but with a 4 cylinder.  I know the bell housing would be different, but would the cross member, transmission mounts, shift plate, clutch/brake assembly, and some other parts all work on 89 Comanche for the conversion?

 

http://atlanta.craigslist.org/antidisestablishmentarianism/cto/5106992115.html

 

Thanks!

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I found this 93 Cherokee, 5 speed, but with a 4 cylinder.  I know the bell housing would be different, but would the cross member, transmission mounts, shift plate, clutch/brake assembly, and some other parts all work on 89 Comanche for the conversion?

 

http://atlanta.craigslist.org/antidisestablishmentarianism/cto/5106992115.html

 

Thanks!

 

 

Looking at this one now, but a little pricey for a parts rig...

 

http://atlanta.craigslist.org/nat/cto/5088637885.html

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Another question...  I ran 235/75/15 tires...  I know stock 5 speeds were 3.07 gears and in 89 the tires were 1 size smaller than 235, I think.  So if I decided to go manual, I'm thinking I would keep the 3.55 gears and add a 3.55 front axle, with either manual or auto...

 

The question is with manual will I like this?  I know it will get up and go a little faster with a 5 speed and 3.55 gears, but will it hurt highway driving up around 75 in 5th?

 

All my research is mainly people liking 3.55 gears, but they are also adding larger tires like 31"s, etc...

 

thanks!

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Another question...  I ran 235/75/15 tires...  I know stock 5 speeds were 3.07 gears and in 89 the tires were 1 size smaller than 235, I think.  So if I decided to go manual, I'm thinking I would keep the 3.55 gears and add a 3.55 front axle, with either manual or auto...

 

The question is with manual will I like this?  I know it will get up and go a little faster with a 5 speed and 3.55 gears, but will it hurt highway driving up around 75 in 5th?

 

All my research is mainly people liking 3.55 gears, but they are also adding larger tires like 31"s, etc...

 

thanks!

You'll love it. Don't forget, the top gear has the same ratio in both the 5-speeds and the automatics. For the 5-speed, 4th gear is 1:1 and 5th (overdrive) is (depending on year and tranny) 0.72:1 or 0.75:1. With the automatics, 3rd gear is 1:1 and 4th gear (overdrive) is 0.7x:1. 75 MPH won't be doing anything to you that it isn't doing to every XJ and MJ that has an automatic transmission.

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I'm trying to make a list of the parts I will need with part numbers.

 

Found on eBay
 
52003927 - AX15 transmission mount, attaches to transmission then mount on cross member
53004433 - Outer boot cover
53000056 - Bezel
 
Still looking
 
52003929 - Cross member (manual, AX15)
53002864 - Inner boot cover
53005141 - Floor Hole cover
53005395 - Insulator for manual transmission
53001480 - Manual shift lever
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I wish I had 3.55 gears with my manual trans. To answer your 75mph question, with the AX-15 and 3.55 gears you will be sitting at right around 2400rpm in 5th gear.  With 3.07 gears and the same tire size and transmission you would be at 2100rpm.  300rpm isn't that big of a difference.  Worst case scenario would be losing 1mpg, and honestly the difference wouldn't even be that much.

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Thanks everyone, great info!

 

What about the 4wd indicator light, which isn't that important, but curious. I assume I can wire up something on transfer case to the wires on firewall for dash light?

I am curious as well. I just run without it. Conversion post in the link in my sig
I have 91 this was one of the few things it wasn't prewired for. The harness from the 96 aw4/231 combo had the plug wired for it (the two extra wires in the trans plug) I bought a new indicator switch which is on the tcase plugged it up ran two wires from trans plug under hood to dash and boom works like a charm. I have 91 wiring fsm if needed.

If you don't have existing wiring on harness just find indicator switch at tcase and run wires directly to dash.

Thank you. I will try that

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Thanks everyone, great info!

 

What about the 4wd indicator light, which isn't that important, but curious. I assume I can wire up something on transfer case to the wires on firewall for dash light?

I am curious as well. I just run without it. Conversion post in the link in my sig

I have 91 this was one of the few things it wasn't prewired for. The harness from the 96 aw4/231 combo had the plug wired for it (the two extra wires in the trans plug) I bought a new indicator switch which is on the tcase plugged it up ran two wires from trans plug under hood to dash and boom works like a charm. I have 91 wiring fsm if needed.

If you don't have existing wiring on harness just find indicator switch at tcase and run wires directly to dash.

 

 

When you ran the two wires to the dash, did you have some wire or connector already there? Does hte 4wd light wires already come through the firewall but just into the main plug, or did you have to pull the dash and find the indicator and run new wires?  Did you have solder onto points or is there already some sort of wire there?

 

I assume the switch on the t-case has one power wire and one signal wire or do you just run 2 wires from the switch on the t-case to 2 wires on the back of the dash light and your done, no extra power or wiring needed?

 

thanks!

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As stated, I have 91 so there are a lot of things that are kinda just freebies like plug and play cruise and numerous other things the spot for the wire in the trans plug had the place for the wire but no wire, same deal behind dash. It's kinda hard to remember exactly but I will dig out the wiring diagrams in 91 fsm and pass along. I dunno what year you have but I'm sure it will be more involved on a renix. I will post back give me a day or two out of town working

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I would keep looking for a better donor (although that 93 4banger would have been a great axle donor for it's 4.10 gears if it was 4wd).  eventually you'll find a 94+ with a bad engine. :D  or just hit the junkyards.  pullapart.com is awesome if you're by one of their locations.  car-part.com might be of help too.  it sorts purely by part number and those change over the years while a lot of the parts are still usable, so be sure to search for a variety of years.  or search for the big ticket items (even if you don't intend to buy them) and then call the yards to see if they still have the Jeep around to get the little things.  unless I'm mistaken, the pedal assembly can work through 95, maybe even all the way to 01.  might have to fiddle with the brake selector switch to make it work.

 

flywheel has to come from am 87-90 (to get the right CPS notches so the truck will run).  clutch can come from any year.

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