4.0 & AX15 swap into CJ

[jeepindavis]

So here it is - after reading so many posts on this site about improving my beloved CJ I have come across a wrecked '98XJ manual Transmission with a NP231 Transfer Case and am going to attempt (with you all's help and guidance) to install this driveline (maybe except the NP231) in my '84 CJ.

This raises 100's of questions in my head...

how do I get fuel into the rail without my mechanical pump?

How do I modify the speedo/temp sensor/oil press for the new driveline?

How well does the AX15 shift lever fit into the CJ tub?

Do the engine mounts on a H.O. 4.0 match our old AMC 258 i6 / 4.2l 's?

????

What do you guys think? Many have suggested injecting the CJ's and swapping heads/exhaust manifolds. This seems like a do-able job. Let me know. Any advice and/or suggestions are greatly appreciated!

 

[RockScar]

how do I get fuel into the rail without my mechanical pump?

How do I modify the speedo/temp sensor/oil press for the new driveline?

How well does the AX15 shift lever fit into the CJ tub?

Do the engine mounts on a H.O. 4.0 match our old AMC 258 i6 / 4.2l 's?

????

What do you guys think? Many have suggested injecting the CJ's and swapping heads/exhaust manifolds. This seems like a do-able job. Let me know. Any advice and/or suggestions are greatly appreciated!

I'm in the middle of this exact swap! Well, mine is out of a '00 tj...
But your ?'s:
-You can either get a fuel tank from a 4.0 YJ and turn it around in order to use its in-tank pump, or as I'm doing, use an external pump. This is the next thing I'm doing actually. I'll be using a new pump for a mid 90's F350, filters from a WJ,(exactly which one I need to research) and replacing the lines after that ti the fuel rail with FI line.
-I'm using the Dana 300 , so the speedo will remain CJ. The others I'll replace with aftermarket gauges for a TJ
-shifter fits fine, I think I'll have to trim a little metal from the rear of the stock CJ tranny access hole though. Maybe 1/2".
-No. Some guys bolt the CJ mounts to unused hole in the block, I made my own and used the 4.0 engine adapters. I can send you pics, but I bought a set of M.O.R.E motor mounts and had them welded to the end of sections of 3" square tube, and bolted those to the frame. I think MORE sells mounts just for this though.

 

[jeepindavis]

Very cool! You're my new best friend! So how did you decide on the F350 external fuel pump? and why would you need a different filter?

Did you use the Novak clocking ring to mate the AX15 to the Dana 300 ? I thought that some of the research from this forum said that these two didn't bolt up without that adapter.

Bummer about the motor mounts. That's soundling like it might be some work.

Any pics would be greatly appreciated.

 

[AussieCJ7]

I did the 4.0L and AW4 but the questions you have asked the answers are the same as your combo

1. Mounts unless you have a very late 4.0L block the holes for the AMC 258 i6 / 4.2l engine mounts all exist there is just one hole that has a fine thread bolt compared to the rest The easiest option is to use stock mounts IMHO
2. Fuel pump I used an external bosche 0944 pump bit of overkill but wa the right price and very easy to work with External pump is easier but is a bit noisy and less durable than an in tank pump. You can modify your fuel sender to include an in tank pump, just takes a little messing around but been done plenty of times. You can use almost any pump that has the right Pressure. Depend on if you have OBD1 or OBD11 system as to what that pressure is

3. Novak adapter/clocking ring yes I used this as while the spline count and bolt patterns are right the output shaft of the tranny is a little too long so the clocking ring acts as a spacer. You can use other clocking rings but liked this one as I knew it was the right thickness and included oil seal rings machined into the mounting surface

Few points you havent asked but you need to think of

1. OBD1 Vs OBD11 OBD1 is much easier with only 5 wires to hook up to run and about 7 or 8 to make it run well. It is also a "dumb system" that doesnt really know to much about mod's etc so if you go towards forced induction latter it is the easiest to fool. OBD11 takes a lot more wiring but you can get a lot more info on the running state from the system via scan gauges etc even in real time data. If you dont provide all the sensors inputs even if your not running them then it will throw codes that can be an issue for emissions test but there is plenty on the web to help you work through this

Your 98 is OBD11

2. Aircon pump location on my 95 engine it was below the power steer pump just meant i had to lift my engine mounts a bit to avoid it hitting the chassis when the mounts flexed

3. Speedo adapter for VSS I used one out of a YJ with 4.0L it has both mechanical and electrical output so runs stock speedo in dash and the computer I believe dodge trucks also had them

My advice is spend a few hours with google and build a folder of notes for your swap you will need full FSM for CJ and XJ of the right years and need your research as each swap is a little different. But the results are more than worth it

Cold morning walk up to the CJ turn the key and fires first go and a bit of extra grunt

To be honest with you though for all the work and the "extra" stuff that wasnt needed for the engine swap but I included in my project anyway I should have went a Ford or GM injected V8

If you can get the whole XJ wreck as a donor then you will save a lot on the "little" parts

 

[jeepindavis]

Few points you havent asked but you need to think of

1. OBD1 Vs OBD11 OBD1 is much easier with only 5 wires to hook up to run and about 7 or 8 to make it run well. It is also a "dumb system" that doesnt really know to much about mod's etc so if you go towards forced induction latter it is the easiest to fool. OBD11 takes a lot more wiring but you can get a lot more info on the running state from the system via scan gauges etc even in real time data. If you dont provide all the sensors inputs even if your not running them then it will throw codes that can be an issue for emissions test but there is plenty on the web to help you work through this

Your 98 is OBD11

2. Aircon pump location on my 95 engine it was below the power steer pump just meant i had to lift my engine mounts a bit to avoid it hitting the chassis when the mounts flexed

compressor is on pass side at the top end of the engine on the '98 - no problem there.

3. Speedo adapter for VSS I used one out of a YJ with 4.0L it has both mechanical and electrical output so runs stock speedo in dash and the computer I believe dodge trucks also had them

this sounds cool but my understanding is the speedo gear is in the Transfer Case and if I keep the Dana 300 I won't need to worry about this


To be honest with you though for all the work and the "extra" stuff that wasnt needed for the engine swap but I included in my project anyway I should have went a Ford or GM injected V8

If you can get the whole XJ wreck as a donor then you will save a lot on the "little" parts

already have the '98XJ - complete rolled vehicle. $500 to my house. driveline sounds strong. So this one is here and I have a '98XJ runner so I'm intimately familiar with the system.

Thanks for the advice. More questions to come.

 

[AussieCJ7]

Yes the Dana 300 has the speedo gear but the issue you have is you need a VSS signal (electric pulse indicating speed) to make the PCM run correctly even more critical on OBD11 so you need to create both a mechcanical speedo signal and an electric one this the adapter with a magnetic pickup plugs inbetween the Transfer Case speedo gear and the cable

 

[jeepindavis]

I'll be using a new pump for a mid 90's F350, filters from a WJ,(exactly which one I need to research) and replacing the lines after that ti the fuel rail with FI line.
-I'm using the Dana 300 , so the speedo will remain CJ. The others I'll replace with aftermarket gauges for a TJ

Howdy RockScar! How's the swap going? I had some additional ?s about your previous post as well as some new ones...

Fuel pump - do you have a PN?
TJ guages - PN or where are you getting them from?
Driveshafts - stock CJ or something else?
tranny mount - stock CJ or donor or something else?
O2 sensors - did you weld in bungs in your stock exhaust or reuse donors or deletes?

Hope things are going well for your project! Any photos or advice you have is appreciated!