Determining t-case input shaft length without t-case in hand?

[clemsonzj]

Hey all,
I understand the discussion regarding input shaft length has been beaten to death. However, even after searching I couldn't find a definitive answer to my question. I have a '98 5.2L and got it without the t-case on it (it was a 249 obviously). Anywho, I got a 231 to throw in and I need to know if there is a way to determine what the proper input shaft length would be for the 249 that came with it. The 231 I got has the 23 spline but the short input shaft length (~.5" I believe). Additionally, what are the consequences of running an input shaft on the t-case that is too short? Any help would be appreciated. Thanks in advance.
Max

[jfowlzj95]

This should help.

this should help ya... the only one I don't know about are the ones that came with the AX15.....
ZJ 93-93.3 4.0L aw4 = short
ZJ 93-95 4.0L = medium with internal collar
ZJ 96-98 4.0L = medium without internal collar
ZJ 93-95 v8 = long
ZJ 96-98 v8 (both) = medium without internal collar
short = .750" exposed
medium = .840" exposed
long = 1.55" exposed

edit to add more clarification for the archives

[clemsonzj]

Thanks for the info. So to answer my second question though, if the input shaft is too short will it not clear the rear seal on the trans thus not actually sealing?
Max

[jfowlzj95]

Yeah if the input is too short it will not seal properly.

[clemsonzj]

Okay, well so in order to measure properly, just measure from the face of the plate that the input shaft goes through to the end? And I'm looking for one that is ~.840"? Thanks again
Max

[clemsonzj]

Thanks for all the help thus far. My final question is, I got the 231 from a yard and they said it was from an XJ. How can I cross-reference the serial number or something to tell what exact year and model Jeep its from? I thought I could use this website:
Transfer Case Jeep, Remanufactured Transfer Cases, Save Money - Drivetrain.com
But they don't have cases based on the assembly number and the other numbers I pull off the case itself have no similarities to the part numbers listed on that site and I want to make sure that I get the correct input shaft with the correct gear-cut....
Max

[xj-to-zj]

I'm doing the same swap on my ZJ. I have a 96 with the 249 and have a np231 with the long input shaft. Can that be directly used on my 96 or do I have to swap to the medium input shaft length?

[fpkites]

The input shaft on the donor has to be the same length as the vehicle it's going into. A simple search could have come up with that.

Now, go back to the drawing board and search how to swap input shafts between cases. It can be done.

[Tommy]

I just purchased the atlas from Matt and we ordered the long style input. I didn't post this in my build yet but when I went to mount the atlas there is a about a .75" gap between the mating surfaces. The drivetrain was out of my 94/5.2/46rh/249. I swear that the output of the tranny is flat with the mating surface of the tranny. Sure as hell doesn't look exposed to me. On the Atlas website it mentions that a 1" spacer is needed for some applications on the ZJ, so I just ordered it and this really isn't a big deal. Just somewhat of a weird issue. I will edit this post with some pics when I get home.

I also had to swap the tcase input when I swapped the 242 in...