how to tell condition np 231

going to the junkyard to snag a np231 transfer case from a Cherokee, there are lots to choose from but how can I tell which one is in good usable condition and not beaten to crap? long story short I don't have a transfer case in my jeep so I'm needing one asap, once I obtain the case my plan is the replace the seals and little friction pads on the shift fork. I really don't want to replace the chain if I don't have to, money is a little tight right now so what ever I can do to keep cost down.

What is your time worth?
Imho if you are going to refurbish a junkyard case, it's all or none.
Pull it apart, if the pads are worn, replace them. If the chain has excessive slop. Replace it.

so there is no way of telling the condition or the chain and bearings without pulling the case apart? and AutoZone sells a remanufactured 231 for 300 plus a 300 dollar core charge I do have a old 249 t case sitting around I could give them. would that be a better option

You could shift it into 4wd, grab the yokes and check the chain for play

Pulling the 231 apart really isnt difficult, just go for it

Remove the front driveshaft.. turn the front output left/right somewhat quickly. You can usually hear the chain slap the outer case half if it's that far gone.

~$200 would buy you a new chain and master rebuild kit.

Draven1474 said:

so there is no way of telling the condition or the chain and bearings without pulling the case apart? and AutoZone sells a remanufactured 231 for 300 plus a 300 dollar core charge I do have a old 249 t case sitting around I could give them. would that be a better option

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if they check the tags they won't take it, has to be the same part or no core exchange (I work at a parts store).


There are only 2 things that really go bad in a 231, the shift fork pads (cheap at the dealer) and the chain (cheap online). the bearings occasionally go bad but usually only if the fluid gets really burned up or run really low. the 231 is a tank it can handle just about anything but being low on fluid.

alright, I will scavenge the junkyards tomorrow, and find a good decent one then give it the parts it needs! thanks all for your input!

Do you have a link for the $300 autozone case? The cheapest I could find on their website was $600 plus the $300 core charge

I had the same slop question. Here is what I did:
With the front drive shaft off, and the TC in 4HI, I rotated the front yoke all the way tight one direction and scribed a mark on the yoke collar and an index mark on the case. Then I rotated in completely opposite and scribed another mark on the collar. This will indicate whatever measure of chain/mechanical slack there is internally. The marks are very slightly less than 1/4" apart on the edge of the collar. When I was in the wrecking yard, I found an identical model, and with less miles on it. 160K. Did the same test. Same result: slightly less than 1/4". My TC is working fine. So as a crude indicator, the one in the wrecking yard is probably a good candidate for pulling out. Also, when yoke is rotated with case in N, there are no other suspect sounds.