NP231 Problems, '97 TJ

Jul 11, 2004 11 Replies

I'm having some odd noises while driving around that sound like a worn brake pad grinding against the rotor. There's also a bit of what I can only think to describe as a rotational sound ('chup chup chup') that's seeming to be only half as fast as the tires are moving (making me think drivesahft or the like). When I pull or push slightly on my transfer case shift lever while in



2wd, it intensifies ALOT. I don't think the noise goes away while in 4wd h/l, but if someone thinks it's relevant i'll confirm on my next drive.

What the hell is wrong here? Is my transfer case about to s*it the bed on me?



__________________ '97 TJ 4.0 A/T Alarm w/remote start PCW EMR050 15" wheels BFG AT T/A KO's 31x10.50 KC 46 series fog lights Front tow hooks Front bumper end-cap delete Banks Power Torquetube header Airaid drop-in replacement filter Alpine CD head unit Audiovox Sirius satelite radio tuner Uniden Beartracker BCT12 scanner Yaesu FT-2600 VHF Ham Radio


I have had 2 NP231 wear out the chains, and what happens there is the chain scrapes on the bottom of the case. I also had one 231 kind of explode on me.

John > I'm having some odd noises while driving around that sound like a worn brake

Could I crack it open and replace the chain or is there more to it than that?

Shawn

Search the net, there is a chain from a ford or a chevy? that fits the np231 and is stronger and bigger. Nick

I don't recall any rust other than the normal surface rust on everything. I'll check tomorrow in the daylight again to be sure. I saw the pic with the chain in it and how it fit in there. How could it be rubbing anything? Does it stretch? I did try it in 4wd earlier today and it seemed to act the same way, with any pressure up or down on the shift lever causing a stronger grinding sound. Man I just hope it doesn't explode like the one dude just said his had done.

Shawn

How does applying pressure on the shift lever work into your diagnosis?

Shawn

everything.

I have the same problem and have been putting off replacing the stretched chain. For sanity's sake, does the chain engage(turn) when only driving in 2 Wheel High?

I had this same thing happen in my '99 TJ and it was the rear differential going from towing too much weight. After a few days, the chup-chup sound started sounding like an M-60 (really fast, loud popping at highway speed) and I took it in. Blown diff.

Thanks, Matt

Mine exploded from trying to climb a rock ledge that I shouldnt have tried.

John > I don't recall any rust other than the normal surface rust on everything.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required