Transfer Case spline swap out

I have a '92 XJ, AW4 with the 23 splines, and a 242 transfer case.
The transmission died on me, unfortunately. So I purchased a 1990 AW4 with 21 splines and an attached 231 TC.

My issue with just placing the new TC in with the new transmission is that there is a different wire harness on the output side of the TC, presumably for the "4WD sensor", the thing that turns on the 4wd lights on the dash. Also, I'd prefer my 242 for other reasons, lets not make this an argument of which is better or you should use this or that, but try to keep it to my question:

Is it possible to open up both TC's, pull the input shaft from the 231 and place it into the 242, making it so that the 242 has the 21 spline shaft?

Also, on an information portion of things, something I noticed about the transmissions themselves...
The 21 spline AW4 has the model number 30L40, where the 23 spline transmission has the model number 30L43. I don't know for sure, but I assume this would be a way for people to tell without removing the TC what spline count they have. (I see people all over asking what their count is, mostly in '90s, and I haven't seen this solution before, but I am only a single sample size so someone should double check this)

No, you cannot swap the internal parts from the 231 to the 242.

You may be able to swap the output from your old trans to the the new trans. Read this - http://www.naxja.org/forum/showthread.php?t=1053970

You can swap the input gears as long as you get the right one.Read this.....
http://www.novak-adapt.com/knowledge/np_nvg_input_gears.htm

RCP Phx said:

You can swap the input gears as long as you get the right one.Read this.....
http://www.novak-adapt.com/knowledge/np_nvg_input_gears.htm

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Hey Forrest,NO,YOU cant,,he wants to swap parts from a 231 to a 242!!

OP - I'm fairly certain you can't swap the output shaft either, sorry for the bad news...

I thought the input gears were the same? (But don't trust me... I've never had a 242 cracked-open.)

daemon512 said:

Is it possible to open up both TC's, pull the input shaft from the 231 and place it into the 242, making it so that the 242 has the 21 spline shaft?

Click to expand...

kastein said:

Hey Forrest,NO,YOU cant,,he wants to swap parts from a 231 to a 242!!

OP - I'm fairly certain you can't swap the output shaft either, sorry for the bad news...

Click to expand...

Might want to slow down and re-read!The input gears can be swapped!

I'v installed 242 input gear to a 231.. from a 94 XJ to an 87 YJ.

RCP Phx said:

Might want to slow down and re-read!The input gears can be swapped!

Click to expand...

That's funky as hell, the planetary set is indeed the same part number (so the input gear diameter/helical cut is the same obviously) but there is only 1 input gear for the 242 I checked and 4 different part numbers for the 231 input gear depending on what it's going in and 21/23 spline changeover, and none of them match. I wonder why Chrysler did that?

And yes, I am fairly certain you can swap the AW4 output shafts (hell, a guy on here put the output shaft from a 94 AW4 into a Toyota Supra A340), but it's gonna mean pulling the whole trans apart sadly.

The chart shows the factory configurations,but the gears will interchange as long as you get the correct one,the differences are in the transmission/adapters used not the transfer case.

I tried it this morning, and it can be done. As was said, I had the right years, it looks like (on further research) pre-1995 are swappable for the input shafts. Either way, it worked and the TC went back together with no problem.

Now, unfortunately, I'm having issues mating my transmission with the engine. My flywheel won't turn so I can connect it to the torque converter, and I can't figure out why. Back to research >.<

You put the torque converter in the trans before bolting the two together right? Always fully insert the TC into the trans (it should sit below the plane of the bellhousing edge, and makes 3-4 distinct clunks as it seats, you will need to spin and wobble it to get it to seat) before mating it to the engine... or you will damage the torque converter and transmission fluid pump.

The torque converter was already on the transmission, but I'm thinking it wasn't fully on (the person I got the tranny from may have taken it off and not put it on properly). I'm going to have to drop the transmission again and figure that out...without help now >.<. I'm hoping I can get it on without taking it out from under the vehicle, and get it all to work out nicely with some fancy jack work.

daemon512 said:

...Now, unfortunately, I'm having issues mating my transmission with the engine. My flywheel won't turn so I can connect it to the torque converter, and I can't figure out why. Back to research >.<

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Pull all the spark plugs out, then rotate the fly wheel with a socket on the bolt until you will be able to reach one of the bolt holes for the TC through the lower opening. Then try to align the TC that same way before positioning the transmission. Once you get it up there, keep the bellhousing bolts loose, then spin the TC to line-up the bolt (keep it a little loose too). After that, you can rotate the engine from the front with a socket to line-up the other TC bolts on the flywheel. Get them all started the first time around, then tighten them down after they are all in.