im new just very perplexed with this jeep thing my yj 92 4.0 999 auto 231j i love but has given me hell the last few weeks started making the clickity clack an scrapeing noise so i checked fluid levels transfercase was dry so i ordered a used np231j on ebay went to put it in and noticed input shaft to short so i split cases on both and put my old input shaft in after close inspection and measurments i oked it put it all together and i still have the clickity clack put transmission in gear and transfercase in any gear even nuetral it makes same noise speeds up and slows down with transmission gear change What do i do ? any ideas

might have done some damage to the transfer case but i really sont have a clue other then that check all ur fluids even in the diff the make sure that's not a prob

Are you sue it is the T case and not the tranny?

I agree check all your fluids including your rear diff.
Get the jeep on jack stands. make sure it is secure,and have a friend run the jeep while you closely inspect everything up close to pinpoint where the noise is coming from.
good luck let us know what you find.
did you reuse the same tailshaft housing? could be that bearing.

scrambler has a point it might just be the fact u put parts from the other transfer case causing the prob