AX15 to AW4 conversion

Pat Goode

Pat Goode

Member
Joined
Sep 19, 2018
Messages
64
Location
Uk
I would like to say a huge thanks to this site for the invaluable information obtained. Enabling me to complete the AW4 conversion on my 1997 Wrangler.
I followed the excellent articles posted by Stu Olsen.
 
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Nice job on getting it installed and working!

Stu Olson's website at https://www.stu-offroad.com/ is just plain awesome, he's a really good guy too. He and I wheeled Death Valley together many years ago and had a ball.

Did you also add an aux cooler to your new AW4? They tend to run hotter than most other automatics.
 
bromel said:
Must have been a tricky install. Did you need new driveshafts?
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The front drive shaft is on the limit with slightly less spline showing than not. It was improved as I had just swopped the front axle for a high pinion off a 2.5 turbo diesel XJ 3.73 ratio. I also swopped the rear for one off a 2.5 petrol TJ 3.73 ratio. Most TJ's I belive imported to the UK were fitted with Dana 44 LSD axles as standard.
On the rear I used a 231 tranfer case again off a 2.5 diesel XJ which has an internal spline output. This gained back nearly 2" so the existing rear shaft is fine.
 
Jerry Bransford said:
Nice job on getting it installed and working!

Stu Olson's website at https://www.stu-offroad.com/ is just plain awesome, he's a really good guy too. He and I wheeled Death Valley together many years ago and had a ball.

Did you also add an aux cooler to your new AW4? They tend to run hotter than most other automatics.
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I used the oil cooler pipes and external oil cooler as fitted to the donar XJ. I fitted the cooler in front of the rad but haven't used the Trans cooler internal to the Rad. (early days)
 
Pat Goode said:
I used the oil cooler pipes and external oil cooler as fitted to the donar XJ. I fitted the cooler in front of the rad but haven't used the Trans cooler internal to the Rad. (early days)
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I'd add that internal cooler in the radiator and plumb the external cooler into the system to further cool the output from the radiator's internal cooler. The ATF would certainly be a lot happier with the additional cooling. Heat is an automatic transmission's worst enemy.
 
Jerry Bransford said:
I'd add that internal cooler in the radiator and plumb the external cooler into the system to further cool the output from the radiator's internal cooler. The ATF would certainly be a lot happier with the additional cooling. Heat is an automatic transmission's worst enemy.
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I've fitted a Trans temp gauge as per the write up and on normal road miles at OAT 65F its running at about 176F Do you know the thread size for the Radiator connections? As its the original Rad these are a bit rusty so not sure they'd easily seal. Hense not using rad cooler to start with.
 
Pat Goode said:
I've fitted a Trans temp gauge as per the write up and on normal road miles at OAT 65F its running at about 176F Do you know the thread size for the Radiator connections? As its the original Rad these are a bit rusty so not sure they'd easily seal. Hense not using rad cooler to start with.
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I believe mine was 5x8x18 but it has been too many years since I messed with that. I just don't believe that one single passive cooler up front is enough for an automatic, especially the AX-4 which tends to run hotter.
 
NPT sizes are confusing me some what! The parts book says 5/8 but a 3/8 x18 NPT tap lookes to be right for the threads in the radiator. Just want to be sure I'm ordering the right size hose tail. We don't use NPT much as the UK uses BSP. (British Standard Pipe) Parts would need ordering on line.
 
I have heard from a good source that when installing an AW-4 into the TJ the ECM and the TCM have a difficult time talking and when the transmission shifts the power output of the engine drops off dramatically and becomes very sluggish.
Ask MR BLAINE for clarification; I believe he has experience with this problem.
 
CharlesHS said:
I have heard from a good source that when installing an AW-4 into the TJ the ECM and the TCM have a difficult time talking and when the transmission shifts the power output of the engine drops off dramatically and becomes very sluggish.
Ask MR BLAINE for clarification; I believe he has experience with this problem.
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Ok thanks, worth watching out for. Is this a problem that occures straight away, or develop over time?

Just thinking! there are no inputs as I recall only outputs to the TCM. It may be because the canbus was connected. I put a plug on the canbus connections so i can leave disconnected unless needed to read codes. It also prevents the engine warning light being triggered.
 
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From what I understood when I had the conversation with the knowledgeable source; the problem occurred as soon as the TJ was driven. You will notice the loss of power after 2800 rpms (IIRC).
 
CharlesHS said:
From what I understood when I had the conversation with the knowledgeable source; the problem occurred as soon as the TJ was driven. You will notice the loss of power after 2800 rpms (IIRC).
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He has already done the conversion. That conversation should be had before the conversion is done so that mistake isn't made. It also responds much better when tire sizes are close to stock.
 
mrblaine said:
He has already done the conversion. That conversation should be had before the conversion is done so that mistake isn't made. It also responds much better when tire sizes are close to stock.
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Sorry I don't understand this reply.
I've done about 20 Miles on it now and it pulls fine. revs with good power well above 3000 RPM
 
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