Trans or T-case noise?

[The_Dealer]

I have an 03 KJ 3.7/42rle/np231 with almost 200k miles. Its making this humming/groaning type noise that starts at 20mph and gets progressively louder, like a set of mud tires. It originally came with the NP242 full time tc, which was replaced with a lower mileage NP231. The noise was there before I swapped the tc, but I did notice some metal in the trans pan when I installed the TransGo shift kit. With the trans in drive/tc in neutral, I had someone apply throttle until I heard the noise. The noise is coming from somewhere between the rear of the trans and middle of the tc. I'm also hearing a clicking sound from the middle of the tc(chain stretch?), and there's a slight bit of play in the front and rear output shafts. I've never run the tc in neutral and trans in gear so I don't know if that clicking is normal, I don't hear it when I'm driving. Looking at the fsm, it looks like there's just the trans output bearing and tc input bearing. It doesn't specify whether the extension shaft has bearings, but from the picture doesn't look like it. What's the chances my old NP242 and new tc had bad input bearings? How common is it for a trans output bearing to be bad? I guess I could always pull the tc and put the trans in gear and see if the noise is still there. Is anyone familiar with the inside of a 42rle? I should mention that my new tc has the correct input shaft.

[94xjsport94]

I don't know anything about 42RLE's, but a 231 isn't complicated. Dropping it and putting the Trans in gear isn't a bad idea, but there might be an easier way.

[The_Dealer]

Yea, I've been inside quite a few 231's so it isn't a big deal. It might be a good idea to rebuild it anyways, especially if the chain is making the clicking noise. I actually did an sye and full rebuild on a buddy's 231. I did a lot of Google searching and couldn't find anything on a 42rle bearing issue. In fact I couldn't find anything on any auto trans bearing issue, so it could be very rare.

[94xjsport94]

There might be someone with a greater knowledge of 42RLE's and your set up on a liberty specific forum. I know that with XJ's there are a few people who know them inside and out on Cherokee Forum.

[The_Dealer]

Yea, a lot of the kj guys are what I'd consider beginner wrenchers. There isn't very much knowledge on the kj forums beyond the basic suspension stuff. I couldn't even find anyone that knew if there was a difference in tc input shafts between the different models. Nobody really gets into modding kj's like they do in the tj/xj world.