NP242 - On Borrowed Time?

While changing the xfer case oil on my 90 XJ (189K miles), I discovered some pieces of chewed up oil pickup tube and the rubber connector from the filter sitting in the bottom of the xfer case near the drain hole. The oil was black in appearance. I flushed out any residual sludge and felt the chain (it didn't appear unusually loose). Everything is quiet before and after the oil change. I'm not sure if there is a piece of tube still connected to the pump or not. it appears the pieces I got out wouldn't make up a whole length of tube. I plan to pull the rear cover in place under the vehicle to investigate further.

Anyone know if the NP 231 pump and pickup tube are interchangeable with the NP 242? I know someone with one I can retrieve parts from. Also, any reason not to pull the cover versus the whole xfer case. While under the vehicle, the 2 upper bolts on the xfer case appear to be inaccessible without dropping the crossmember and possibly undoing the exhaust. (I prefer the easiest solution).

Also, I would appreciate any tips or advice from anyone that experienced this same problem. I've never seen this before. The only explanation I can come up with is a sloppy chain which dislodged the oil pickup tube.

Lastly, if the oil pump is non functional based on the pickup tube being dislodged, can the vehicle be run in 2 wheel drive near term based on oil splash from the chain alone?

Thanks

If the Tcase is quiet and works, why take it apart? You saw some pieces of hose, no big deal...it's almost 200k miles old. I'd just drive it until it blows...if that ever actually happens.

If you're gonna split the case, definitely remove it from the vehicle first. It's much easier to open it up on a workbench than it is laying on your back.

Unfortunately, most of the debris retrieved was metal (the oil pickup tube), not rubber. The rubber hose retrieved was the connector to the filter screen (about 2" long). I've researched the parts catalog link, it appears the 231 and 242 oil pickup tubes are different from 88-90. Anyway, I have to wait to remove the rear xfer case cover. The vehicle has the fatal Bendix 9 ABS system which has started to experience higher than normal pressure bleed off (pump motor runs excessively). The local Jeep dealer is going to diagnose this week to confirm. Chrysler USA has indicated that the pump assy and actuator piston (part of MC) are under lifetime warranty. The dealer thinks otherwise. I'll report back on how this goes later in the week. It did take the Chrysler USA rep some time to investigate and come back with the answer. I'm still not sure which recall applies. Bulletin 685 was for the Chrysler vehicles which had the Bendix 10 system. I understand the Bendix 9 was used exclusively on Jeep vehicles. If things don't go as expected, I'll be replacing the ABS with a standard brake system from a 94 XJ.

I finally removed the xfer case rear extension and rear cover. I found the oil pump assembly to have a large hole in one of the flanges with several pieces of the outer (internal) drive ring laying in the extension housing. There was no trace of the plastic suction filter ever having existed. Having recently changed the oil, no additional metal chips were found on the magnet or discoloration in the oil during the 2nd draining. So it indeed confirms the original material removed was the pieces of the oil suction tube. There appears to be no other latent damage from having run in the interim without the forced lubrication. The rear output bearing also appears to be fine, I have replacement parts coming from AllChrsyler and will reassemble shortly. The only unknown will be the condition of the input shaft seal from being run dry dry. If it leaks afterwards, I'll be forced to pull the whole transfer case and replace. It did appear even without the oil pump functioning that the internal parts were well coated with transmission fluid.

More to follow.

A success story! Xfer case is operating/shifting smoothly after installation of new oil pump, suction tube/filter, timing chain/gears and new rear oil seal/bushing. The original chain with 190K didn't appear to have a large amount of slop but I changed it anyway. So far the case is leak tight. I used the MOPAR ATF-RTV gasket sealant as recommended by the OEM.

glad to here its working well for you. i had just drained gear oil out of my transfer case. not atf so i just let it drain out and its just as good and there is still no noise after 220,196 miles.

I had a terrible grinding, clanging noise coming from what we thought was the TC. I drained the case and the stuff that came out was black, with little metal flakes and smelled like gear oil....'cause it was, the prev. owner thought it took gear oil.DUH!!(thanks to the generosity of someone in here they gave me another 242)
Turned out not to be the TC but the flexplate. As abused as that TC was it still works today, just it got it back from someone that I let borrow it and they had no probs. with it. I was gonna rebuild it, but if it ain't broke(all the way) don't fix it.
Just goes to show that 242 is tough like its partners, the AW4 and 4.0

it seems like if you bought an xj used the previous owners used gear oil. cant they read.