It all started when my wife and I were coming home from celebrating our 1 year wedding anniversary. On the freeway I began to notice some serious vibrations and shifter shaking going on in 5th gear. I shifted down to 4th and things were a little better. I got off at the next freeway exit. I crawled under my Jeep and noticed oil on the cross member. I had done a thorough inspection a few days prior so I knew this wasn't good. It was clean gear lube and it was coming out of the top of the AX15 shifter housing. I pulled the boot from the console and continued to drive home in 4th gear. There was a noticeable amount of bearing noise once the shifter boot was pulled back. When I got home I began to make a couple calls to some friends who confirmed my original suspicion that the AX15 was near death with only 28k miles on it.
I knew that I wasn't going to put another AX15 in. It was either an NV4500 or an automatic. Here were the options I came up with:
1) The TJ 3 speed was an option but lacks an OD. Cost for swap $700-800.
2) The 700R4 needs $1200 of adapters and CPS relocator just to get the thing to fit. That's before you even factor in the cost of the tranny.
3) An NV4500 would be the easiest swap but it was still a manual. Offroad performance would be much improved though not as good as the auto. Its about $2800 to get the NV4500 and parts needed.
4) The Cherokee AW4. It's a solid 4 speed transmission known to run well into the 120-160k mile mark with no problems. It has been used in Cherokees 87-2001. It was also used by Toyota in Four Runners and Supras. Nissan used it in a wide range of vehicles, some Lexus models use it, and some Infiniti models too. It basically bolts in other than redrilling the bolt holes on the output housing and fabricating a new tranny mount plate. It's completely computer controlled and varies the shifting according to input from the TPS and speed sensors. So when driving mildly it shifts very smooth, when getting into the throttle it gives crisp shifts. It's only 1" longer than the AX15. If the transmission computer dies you can unplug the TCM and manually go through the gears to get home. Cost is $650, throw in another $400 to get the TCM, shifter assembly, pedal, cables, and tranny cooler and you have a low mileage 4 speed with around $1000 into it.
The choice ended up being between the TJ 3 speed and the XJ 4 speed AW4. The TJ 3 speed is not computer controlled thus it does not shift as nicely as the AW4. Stu Olson and I picked up the AW4 on a Monday afternoon. This one is out of a 2000 Cherokee with less than 20k miles. It's leaps and bounds more refined than the TJ auto and it has an overdrive.
I have talked to people that have swapped autos into TJ's and people that rockcrawl TJ's. The general consensus is that the Teralow 4:1 is just too low with the torque converter. Therefore I decided to sell my Teralow and roll that $450 into the swap. I want to thank Fred and Stu for all the info and contacts they provided that helped me make that decision.
This swap is done by AEV conversions. They are the ones that take brand new TJ's and stretch them. They were of no help to me. I have never received a response back from them.
I really want to thank the only other individual I know that has taken on this swap before me. That is Bob Basset of California, also known as Scratch on JU. He has a nice write up that you will also want to checkout:
Bob Basset's AW4 write up
His write up is very informative. I'm hoping that my write up will improve upon his in 2 key areas. The first being the wiring portion of the swap. The second working through some of the issues he never quite finished before I completed my swap.
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