Let's clarify the differences in the NP231

While in the process of converting my AW4 XJ to an AX-15, I found a little snag while moving my transfer case from the 98 AW4 to the 90AX-15.

Novak has a very clear description of input shaft lengths:

https://www.novak-adapt.com/knowledge/np-nvg-input-gears

Stu Olson's site has some info about how to get around a long shaft on a short shaft transmission:

https://www.stu-offroad.com//engine/aw-4/aw-4-14.htm

But that wasn't an issue. It looks like the TC input shaft could be an extra 3 inches and it wouldn't bottom out on anything.

So I broke out the measuring tools and went to town. Every measurement proved again and again that the input shaft was not going to bottom out or bind up. So where was the problem?

Bam. There it is. 3 tiny indentions about 120 degrees out.

https://flic.kr/p/2kwUuQN


https://flic.kr/p/2kwTTFP

So what's causing it?

https://flic.kr/p/2kwUuS6

And here's my solution. A little grinder work, clean it up with some brake cleaner and blow all the shavings out, and bolt it up!

https://flic.kr/p/2kwUuPa

https://flic.kr/p/2kwTTEG


So there it is. You can bolt an automatic NP231 to a manual transmission.

Now to see what else is out there, because this is obviously only one example.

Cheers!