So I currently have a YJ 4.2l with a BA 10/5 manual tranny. I want to swap to a 4 speed OD. I have looked at all of the options and it seems for the money, the AW4 would be my best bet. (I would ultimately want to go with a 700r4 Gm but the conversion is going to cost too much) I have done a bit of research but cannot seem to find solid answers to many of my questions. I am sure they may have been answered on here a million times. Unfortunately the search option on this forum isn't the best. So maybe you guys can help get me pointed in the right direction.
So the first questions I have are about actual fit and connection of the unit. I assume I have the answers correct here but just want to check. If I understand correctly the AW4 should bolt to my engine without an issue, as long as it is an AW4 and not a A340 out of a Toyota. Are all the bell housings the same bolt pattern? Is there a difference in a 4cyl and a 6cyl bolt pattern? Not even sure this unit came in the 4cyl. Then in the back I am certain that my NP231 should bolt up, but I do understand there are 2 possible output shaft spline counts (21 and 23). This all should be pretty simple.
My next concern is the electronics. Now my YJ has a carbureted 4.2l and basically no computer controlling it. I understand that the aw4 is an electronic unit, but can run with a stand alone TCU. Or I have seen some guys basically wire a series of switches to make it shift manually. Does anyone have any experience with this, or maybe point me to some decent websites that might help? I am not sure of the connections to my YJ.
Finally is there a certain year or model unit I should be looking for are they all pretty much the same? I can find any info open if they change through the years they were in service.
Please keep in mind that I have weighed all of my options and I am 99% sure this is the unit I want to swap to. I would not like this thread to turn into the "Well you should just use blank unit instead of the AW4". I am particular about the fact that I want a 4 speed OD, and although I would love to have a GM model because they are bullet proof. I am not looking to pay a ton of money for adapter kits. I have considered the 42rh but ruled it out because the AW4 has a much better reputation for being durable. I understand the AW4 can be prone to overheating issues which is easily solved with a large trans cooler. So unless you have some information that contradicts the above statements, I don't think I will be changing my mind on the AW4.
Thanks in advance for your help.
So the first questions I have are about actual fit and connection of the unit. I assume I have the answers correct here but just want to check. If I understand correctly the AW4 should bolt to my engine without an issue, as long as it is an AW4 and not a A340 out of a Toyota. Are all the bell housings the same bolt pattern? Is there a difference in a 4cyl and a 6cyl bolt pattern? Not even sure this unit came in the 4cyl. Then in the back I am certain that my NP231 should bolt up, but I do understand there are 2 possible output shaft spline counts (21 and 23). This all should be pretty simple.
My next concern is the electronics. Now my YJ has a carbureted 4.2l and basically no computer controlling it. I understand that the aw4 is an electronic unit, but can run with a stand alone TCU. Or I have seen some guys basically wire a series of switches to make it shift manually. Does anyone have any experience with this, or maybe point me to some decent websites that might help? I am not sure of the connections to my YJ.
Finally is there a certain year or model unit I should be looking for are they all pretty much the same? I can find any info open if they change through the years they were in service.
Please keep in mind that I have weighed all of my options and I am 99% sure this is the unit I want to swap to. I would not like this thread to turn into the "Well you should just use blank unit instead of the AW4". I am particular about the fact that I want a 4 speed OD, and although I would love to have a GM model because they are bullet proof. I am not looking to pay a ton of money for adapter kits. I have considered the 42rh but ruled it out because the AW4 has a much better reputation for being durable. I understand the AW4 can be prone to overheating issues which is easily solved with a large trans cooler. So unless you have some information that contradicts the above statements, I don't think I will be changing my mind on the AW4.
Thanks in advance for your help.
