Stole this photo off an ebay ad. Looks like the shaft on the trans is flush with the housing, which makes Novak think the NP231 is a long input shaft. This all being said, a short shaft 231 would still engage those splines, would it not? I mean absolute worst case is someone gets a long input shaft and uses a deathwheel to cut it down?
I know Novak has a lot of experience and expertise in this area, but based on how flat out wrong their website has been, and continues to be, on this specific subject renders them a non-authority here.
The end of the output shaft in relation to the end of the housing has squat to do with what input shaft you need in the case. What matters is how much output shaft protrudes from the output seal of the transmission, whether the seal rides on the output shaft like it does in the nsg370 or on the input like it does in the Ax15, and the length of spline machined onto the end. The transfer case needs to meet the tail housing BEFORE the splines bottom out, and the input gear needs to either extend into the trans output seal, or stop before it makes contact, depending on the seal arrangement.
The end of the output shaft in relation to the end of the housing has squat to do with what input shaft you need in the case. What matters is how much output shaft protrudes from the output seal of the transmission, whether the seal rides on the output shaft like it does in the nsg370 or on the input like it does in the Ax15, and the length of spline machined onto the end. The transfer case needs to meet the tail housing BEFORE the splines bottom out, and the input gear needs to either extend into the trans output seal, or stop before it makes contact, depending on the seal arrangement.
I'm trying to find one to bench rebuild and slap a JB mega short SYE on it. Currently have a perfectly good NP231 with a Novak SYE on it and wanted to try and sell it complete, along with having less down time.
JC Jeep
New Member
I know there has been lots of conversation here but the more I have researched and inquired, the more confused I have gotten. My son lives 8 hrs away and I am trying to replace the transfer case on a 1998 wrangler sport, 4.0 with manual transmission. I am relatively sure it is a 23 spline but am getting different feedback on the input shaft length. I have a photo of the tag on the gearbox if it helps.
JC Jeep
New Member
Like your 98, my 99 had an Ax15 manual transmission and the np231 had a long input shaft. The AX15s rear seal is far enough back that you should be able to use a short if that's all you can find, but I like utilizing as much spline engagement as I can.
What the hell happened to that one?
JC Jeep
New Member
It is a mess isn’t it. My son loaned it to a friend and it swarmed on him while traveling down I-35 in Fort Worth. Don’t understand but….. thanks for the feedback on the transfer case.