I have a 91 xj with a np231 double set up I’m having problems with it. It grinds when in 2wd/ disengaged when I engage it works great but just makes a terrible noise if I try to use it disengaged

 

can you get a better angle on the shift tabs for the full 231 side? thats a pretty steep angle for making the shift - perhaps its not resting the fork in 2wd completely?

 

Worn our plastic pads on the shift fork inside the case?

 

So both cases are a fresh build with the 6 gear planetary and the wide chain and gears with sye installed. All new bearings seals and tabs on the shift forks. I’ll get better pictures tomorrow a lot has been done since thoughts pictures were taken

 

Have you had a friend or your girlfriend or wife shift it in the vehicle while you look underneath. This is a custom setup so it could be anything.

I don't have a custom setup like this, but I do have an aftermarket shift linkage like you do and an SYE installed on my 231. Mine gave me problems when a piece of my shift linkage only had 1 ear on it. The company came out with a revised version with 2 ears and it fixed my issue. The ears make sure the shift linkage part that's bolted onto the shifter underneath doesn't get stuck in a position after using your shifter to shift to another setting. So, for example if you are in 4-Hi and you shift to 2-Hi, the old version of the linkage without 2 ears wouldn't shift back to 2-Hi, it would get stuck in between. The new version with 2 ears shifts perfectly every time.

 

Is this recent or has it always done it? Did you assemble it from scratch? If you disconnect the linkage from it and shift it does it still do it?

 

Obviously way out of my normal mechanic range...whats the purpose of this rig, meaning the dual xfer cases

 

this is new been building for a couple years. But without linkage it works fine I believe I need to extend the lever on the cases to keep the linkage flat it’s at an steep angle I’ll post more pictures tonight

 

That is why I asked that question. It sounds like you are not getting it all the way into gear. Let me know how it turns out. I have done lots of custom work like this