Tcase grinding in 4hi and lo

alright some background. a while back i toke my front DS out because the slip yoke okn it was wobbly and made for annoying daily drivability. for that reason i havnt shifted to 4wd in a few months. recently decided to go wheeling and i put it in drove to the spot, put it in 4hi as i roll onto the trail. start to give it a little gas and theres this horrible grinding sound right next to my leg. WTF. this has never happend before and ive taken this jeep through some rough stuff. tried it in 4lo and still have the same sound. went home and took out my DS. tried it in both again and same thing. horrilble grind. tried holding the shifter in different places thinking maybe a linkage issue. but to no avail. oh and its a np 231

any ideas?

Sounds like your driveshaft took out the bearings in the NP231

x2 on what ol man said. luckily for u 231 are easy to rebuild. not too expensive either.

disconnect the linkage (it just takes a big screwdriver to pop it loose) from underneath and shift it by hand from underneath the jeep IN PARK into each position, then hop back in and try to drive after each click to see if it still makes the noise. if not, it's the linkage, if yes, it's the case.

Ok. Just checked the linkage. It still grinds in both when its disco. Should note that while I was under there I noticed a pretty big leak goin on. Think its coming from tailshaft

If this XJ doesn't need to be driven every day I would pull it out and pop it open just to see what is going on inside, sounds like you have a serious problem relating to the output shaft in the tcase. at minimum a bad bearing, if it still drives fine in 2wd the internals may still be in serviceable shape... but you really won't know until you split it open.

unfortunately this xj is my DD. hopefully ill be gettin another jeep by the end of this month that will become my DD and then ill be able to open her up and see whats wrong.. but until then i have to drive this one.

just noticed that it doesnt make this sound when in 4x4 going in reverse..? any ideas why.

also i drained the tcase and went to fill it up.. it takes about 2 qts right? well i put in one and as soon as i went to start with the second it started pouring out the fill hole like it was full.

would you all suggest putting in a junkyard tcase or rebuilding this one.. their both about the same cost wise.

rebuild yours then you know what you have and not taking a chance on the jy one

thats what im leaning towards.. and if i get my new xj soon enough thats what ill do.
but until then this is my DD. and i cant have it immobile for more than one day. if i could get it out rebuilt and back in in one day then id go for it, but ive never rebuilt one or anything for that matter.. im pretty good with a wrench, just never done this.