Hey guys,

I have a 96 xj 4.0 HO with the NP231. Picked it up a couple months ago. Having a problem with what I assume is the t case given my symptoms. When accelerating from a stop in 2wd, between 0-15 mph, I have a serious grinding/vibration/knocking/clunking/all of the above coming from directly under me. Feels like something is gunna fall apart. However, when I throw it into part time 4hi or 4lo, it doesn't happen and accelerates extremely smoothly. I'm going to change the t/c fluid in the next couple days. Really hoping I'm not going to have to replace the entire case though.
Also have a leak in the rear differential that I just now noticed (really wish I had seen that earlier) so I'm gunna get in there and get some fresh gear oil and seal on it. Not even sure if there's any fluid left in the rear differential at this point.
Wondering if the two could be related? Thanks in advance

 

There is a collar in there.
The shift fork rides in that collar.
If the plastic tabs on the fork are missing/worn out it could let the collar move enough to rattle against the locking gear.

 

check the driveshaft

 

X2 on that, or check your yokes also

 

check for play in the rear output by seeing if you can move the DS up or down.

 

Yeah my first thought was the rear driveshaft. However there is no play and it is nice and snug in there (also replaced the ujoints on it which did not help).
Is this collar inside the t case? I have had no experience digging into a transfer case before. Or is there a write up somebody can shoot me a link to?

 

https://www.cherokeeforum.com/f46/ne...-2-door-53136/
I took lots of pictures since I never tore into a T-Case either and posted them in the link above.

 

Awesome that will be very helpful. Thanks a lot!

 

Turns out my rear yoke has a little play in it and has really worn over time. Also my motor mounts are completely shot. Both these contributing to it. I'll see how it feels once I get these repairs done

 

how much lift do you have on it?
My 2nd xj had 3'' lift blocks and coils. driveshaft was too short. barely on outputshaft, causing too much play in it. hopped real bad and clunked. trashed t case. check how for the DS is on the output shaft from t case.

 

i second this, i have the same problem with my 96 xj, real bad vibes and such, due to the driveshaft being so far out on the output shaft it actually bent the rear output shaft slightly, but its still enough that over time it ruined all the bearings and such, i purchased a hack and tap SYE and im replaceing my transfer case today actually with one from a local scrap yard (100 bucks) . i would put your jeep on jack stands and let it idle in drive and check that rear output shaft and see if it looks bent. just my opinion.