NP231 Diagnosis

Imagineer

TJ Enthusiast
Original poster
Joined
Mar 29, 2016
Messages
137
Location
NE Ohio
Anyone out there versed in the specific noises made by NP231 transfer cases? When I shift into 4HI and hit the gas, it makes a sound similar to grinding regular manual transmission gears. The Jeep moves, but doesn't seem to pull as hard as it should.

Knowing nothing about the innards or working of the stock transfer case, I'm asking if there's a possibility this noise is the result of something not adjusted correctly, or is the t-case fubar'd?

I actually discovered the t-case noise a while ago and have been keeping an eye out for a replacement NP231. Recently however, a coworker suggested that the "linkage for engaging the t-case" may be out of adjustment?

Sound plausible?
 
I had a similar noise. Chain was stretched and loose. Replaced chain when I did a new SYE and fixed it. Several possibilities but start by checking out the chain first. Good luck