NP231 tech

RenegadeT

RenegadeT

no shirt,no shoes,no dice
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Joined
Mar 24, 2005
Location
Stokesdale-Greensboro
The 231 in my XJ seems to be acting strange. I can't find a neutral position, and under load I think it sticks in 4Hi, wont go back to 2Hi. Any thoughts before I tear into it?

I also have a good 231, the only thing wrong with it is a rock poked a huge hole in the rear cover, otherwise it is fine. Would it be fairly easy to swap rear covers? Remove slip yoke, remove cover...swap, or would a bunch of springs/gears/balls fall out and need to be re-assembled.
 
If you back up turns out to be no good and you need another. Greensboro Auto Parts U-Pullit had several XJ's with NP231's the other week when I was there. Their prices can't are hard to beat I took a complete disk brake setup off a ZJ and only paid $40 bucks for everything. I also got a complete rotor to rotor HP30 for $75.

I know that doesn't help with your question of why your current transfer case shifts hard but I just thought I'd throw it out there in case you need a replacement.
 
Don't know about the sticking but as far as swapping covers the only thing you should worry about is the pickup tube. It want fall on the ground but may fall out of it's groove and you just need to make sure you put it back.
 
worn/stretched chain?

OK I think I found the smoking gun, I'm going to continue swapping rear covers/oil pumps. When I rotate the new-to-me mainshaft, the chain sticks on the gear, it doesnt freely disengage and wants to continue rolling around the gear. It does this when I rotate it either way. My old tcase seems fine in this regard. I'm not sure if this causes no neutral and difficult to get out of 4wd, but I'll try and see.
 
Hey Tony, if it got hot enough for the chain to stretch, there's a good chance the shift fork pads are worn/damaged too.
Go ahead and replace the pads when ya have it apart. When they wear and allow slop in the range fork and mode fork, shifts become cloudy and difficult.
 
the rear case half/ tailshaft are a easy swap. just remove the oilpump/pickup with the case half and re-install together. if your having trouble shifting and its popping out then it sounds like your shifter pads are worn out or gone. also a easy fix.
 
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