NP242 (Selec-Trac) Transfer Case Problem

[2000XJ]

This weekend I was out wheeling, and completely lost front wheel drive.

Yes, I am fully engaged in 4Lo, and no, it is not slipping out. Essentially what is happening is that I will be in 4Lo (I don't wheel in 4Hi), and my front end will just no longer be engaged. The front driveshaft will not turn, and only the rear does the work.

I haven't heard any loud pops, so I don't think the chain went. I'm thinking that it's an internal issue because externally, everything is the way it's supposed to be.

My current guesses are that either the chain is worn out and slipping or that the shift fork on the inside of the tcase is broken, which is letting the front wheel drive disengage.

Now, for part of the morning yesterday, when I was wheeling and I'd lose front wheel drive - if I shifted into Reverse and backed up a few feet, then shifted into 1-2, 3, or D and accelerated the front end would engage for a bit, but then I'd lose it again.

Any suggestions, thoughts, or ideas as to what it may be? I will be dropping the tcase once I get a chance to see if it's worth fixing or if it'd be easier to just swap in another one.

Thanks!

[Mudderoy]

Well I've only had experience with my NP242. The only issue I've had in the 11 years, are the front and rear seals needing replacing and the chain stretched.

I replaced the chain a couple of years ago, and recently changed the front seal (not the transmission/transfer case seal).

I need to check the fluid levels, but my back glass says the minor leak was fixed.

The stretched chain made a hell of a noise, and bounced the front of the rig a bit.

I'll be really interested to know what the problem is.

[ol"blue]

Could it be possible that the linkage is out of adjustment or damaged and not letting it engage fully?

[2000XJ]

Could it be possible that the linkage is out of adjustment or damaged and not letting it engage fully?

I engaged the tcase from under the XJ by hand to ensure that I was fully engaging 4Lo. It definately engages all the way because I get it for distances at a time - then all of a sudden the front just disengages, but the rear stays in 4Lo.



Mudd - I'll definately keep this thread updated with my findings!

[ol"blue]

I'm new to this so humor me, but does yours have the vacuum disconnect front axle? What year did that change? Sorry if it's a dumb question. I've never owned or worked on an XJ.
Hopefully this will change soon.http://i562.photobucket.com/albums/ss68/DLHTURBO/beerchug.gif

[Mudderoy]

I'm new to this so humor me, but does yours have the vacuum disconnect front axle? What year did that change? Sorry if it's a dumb question. I've never owned or worked on an XJ.
Hopefully this will change soon.http://i562.photobucket.com/albums/ss68/DLHTURBO/beerchug.gif

Well I dug around and I couldn't find the years that the Jeep XJ Dana 30 had vacuum disconnect. I know my 1998 doesn't have it. So 1998+ do not have vacuum disconnect. I suspect the lack of vacuum disconenct goes back at least until 1997.

[ol"blue]

Okay, well I'll see if I can find anything that can be helpful here.
With my limited comp. skills it might take a while.

[2000XJ]

The vacuum axles were stopped in either '92 or '94 - not sure which of those two years. '99 was the last year of the high pinion axles, '00 and '01 got low pinion D30's.

Definately, if you come across anything that's helpful let me know.

My XJ is getting back to my house at some point today (my buddy trailered it up to NY last wee and is returning today), so I'm going to start to organize my tools and such, then start pulling the skids, driveshafts, etc, so I can remove the tcase later this week or next week.

[ol"blue]

I hope it's something simple. This Jeep stuff is all new to me.

[Mudderoy]

I've been pleasantly surprised how simple everything is on the Jeep. I'm sure it will be a simple issue and fix, I just hope it isn't an expensive one.

[2000XJ]

I've been pleasantly surprised how simple everything is on the Jeep. I'm sure it will be a simple issue and fix, I just hope it isn't an expensive one.

Bolded for emphasis! I hope it's not expensive either. I'm still running tight on cash :boohoo:

There is someone parting out an XJ near me and it has a NP231 in it. It's from a '98 but it may be worth purchasing depending on what I find. Unfortunately I won't have my rig back from my friend's house until later in the week due to a lack of communication on my part :mad0090:, so the tear down has been postponed.

[whowey]

I'm new to this so humor me, but does yours have the vacuum disconnect front axle? What year did that change? Sorry if it's a dumb question. I've never owned or worked on an XJ.
Hopefully this will change soon.http://i562.photobucket.com/albums/ss68/DLHTURBO/beerchug.gif

None of the XJ's with the full-time cases had a vacuum disco...

But vacuum disco died its final death in 1992(IIRC).

The early NP242 used a clutch system to connect the output shaft to the front output. But I thought that in low range that was locked out and it used the chain like an NP231.

[Mudderoy]

Bolded for emphasis! I hope it's not expensive either. I'm still running tight on cash :boohoo:

There is someone parting out an XJ near me and it has a NP231 in it. It's from a '98 but it may be worth purchasing depending on what I find. Unfortunately I won't have my rig back from my friend's house until later in the week due to a lack of communication on my part :mad0090:, so the tear down has been postponed.

I wouldn't hesitate to swap in a 231 for a trail rig. I wouldn't get rid of that 242 though. Rebuild it as you have time, I wish I had a spare. Of course I'm getting a bit ahead. It's going to be a simple problem/solution, and CHEAP! :D

[firehawk]

After looking thru my '00 FSM, it appears to me there could be several causes. Chain sprockets are missing teeth, OR one or more of the planetary gears are missing teeth. If the chain was broke, you would never have drive at the front wheels.

I'd pull the drainplug and see if any metal chunks come out with the ATF fluid.:thumbdown:

Just my .02.

[Primo]

I hate to be the one to kill your week, BUT I had the exact same problem with mine and $900.00 later my t case is all better!! Of corse I hope it is not the same thing that you have. I had to have mine rebuilt, what had happened was that the shaft that spins the big cog started to wear and the cog would slip to the edg of the shaft where it would spin free of the splines,
it had almost worked its way threw the side of the case. any hoo I had to replace the shaft (caus it had worn off half of the splines) and the cog and the chain and a lot more.
I should of just done the np231 and put a teralow kit in it, they told me it would be like 3 or 4 hundred not 9 so I went with the fix. If I had it to do again I would do just that np 231 and a terralow kit you could do it all for less than it might cost to fix the 242.
I even like my 242 the part time is awsome in the snow on the freeway but the clutch drive for the part time is week so??????
Just my opinion tho Good luck!!!

[2000XJ]

WOW! $900 is out of the question! I can pick up another tcase for $100-$200 so depending on whats wrong that may just be the better option.

I would definately probably keep my NP242 and fix it as money becme available then keep it as a spare tcase. This way I can rest easy when wheeling or if the one in my DD takes a crap I can swap this one back in.

I'd love to go with the NP231 and Tera kit, but I can't swing any upgrades right now. Let alone I can't get the parts to fix this or a tcase to replace it for some time yet.

There is alot that can go wrong within the NP242 so the options of "could be's" are nearly endless.

[muddeprived]

WOW! $900 is out of the question! I can pick up another tcase for $100-$200 so depending on whats wrong that may just be the better option.

I would definately probably keep my NP242 and fix it as money becme available then keep it as a spare tcase. This way I can rest easy when wheeling or if the one in my DD takes a crap I can swap this one back in.

I'd love to go with the NP231 and Tera kit, but I can't swing any upgrades right now. Let alone I can't get the parts to fix this or a tcase to replace it for some time yet.

There is alot that can go wrong within the NP242 so the options of "could be's" are nearly endless.

Best thing to do is just pop it open and see what's going on inside. If i were you, i'd just go spend $$ on a 231 and put the 242 aside as a spare like you said. The 231's can be had for pretty cheap if you know where to look.

At least 2wd still work so you can still drive it. :)

[Mudderoy]

I want a spare 242 so I can rebuild it, and put a Tom Woods SYE in it. Once that is done I can just swap in the rebuilt 242 and the new drive shaft.

Of couse that means I either sell the original 242, or rebuild and put another SYE in it. :(

[Primo]

:):D
WOW! $900 is out of the question! I can pick up another tcase for $100-$200 so depending on whats wrong that may just be the better option.

I would definately probably keep my NP242 and fix it as money becme available then keep it as a spare tcase. This way I can rest easy when wheeling or if the one in my DD takes a crap I can swap this one back in.

I'd love to go with the NP231 and Tera kit, but I can't swing any upgrades right now. Let alone I can't get the parts to fix this or a tcase to replace it for some time yet.

There is alot that can go wrong within the NP242 so the options of "could be's" are nearly endless.

Yeah I agree I was surprised with the price after it was all done!!!! Thats why I say get the 231 you have a 99% chance of saving money!
Plus you can find all the parts to do it off the one being parted out down the street and or ebay.


I want a spare 242 so I can rebuild it, and put a Tom Woods SYE in it. Once that is done I can just swap in the rebuilt 242 and the new drive shaft.

Of couse that means I either sell the original 242, or rebuild and put another SYE in it. :(

MMMMMMMMMMMMMM Tom Woods he lives 15 minutes away from me and his shop is prolly only 20 minutes away from me he is an awsome guy! with awsome parts!!! My sye and drive lines will be Tom woods gota love the woody's:D

[Mudderoy]

:):D

Yeah I agree I was surprised with the price after it was all done!!!! Thats why I say get the 231 you have a 99% chance of saving money!
Plus you can find all the parts to do it off the one being parted out down the street and or ebay.



MMMMMMMMMMMMMM Tom Woods he lives 15 minutes away from me and his shop is prolly only 20 minutes away from me he is an awsome guy! with awsome parts!!! My sye and drive lines will be Tom woods gota love the woody's:D

Yep I've heard nothing but good about Tom Wood's stuff.

[Primo]

Yep I've heard nothing but good about Tom Wood's stuff.

Did you mean to say "I've heard nothing but goodabout tom woods or actually what you said???

[Mudderoy]

Did you mean to say "I've heard nothing but goodabout tom woods or actually what you said???

Yeah, that's what I ment, wait what did I say?

Hmmm maybe I was thinking about Rusty's when I wrote that. :rotfl2:

[jimwww]

Let us know what happens when you solve the problem. I have selec-trac and have had no problems.

[2000XJ]

The tcases are typically pretty durable. I can't say that I've been nice to mine, so it's probably my own fault.

As of right now, the immediate solution is going to be a straight swap. I found an NP231 in my area for a great deal out of a '98 XJ, and it should bolt right up. I will be pulling my NP242 this Wednesday if everything goes as planned, and I'll be picking up the NP231 on Thursday (hopefully). Then the following week I'll bolt it up, make sure it works as it should, then swap the SYE from my NP242 to the NP231.

Then down the road I'll rebuild this NP242.

Does anyone know if I could easily swap the output shafts on the NP231 and NP242 so that I don't have to re-do the hack 'n tap?

[BlueXJ]

I am not sure if there was a change but the Renix era 242 can not interchange shafts with the 231. I have several 242 spare transfercases(3 I think) but they are all Renix which has a different spline count than the H.O. (21 vs 23) Internally they are identical though.

[2000XJ]

Yea, I'm definately going to look into it. Another source said the same thing Blue, so I'm rethinking my approach. Regardless, I'm going to get the 231 because it's a great deal and I do need it. Worst case scenario, I just redo the HnT, and worry about the 242 later.

[2000XJ]

Well as of this afternoon, the NP242 is out of the XJ. I'll be picking up an NP231 tomorrow, and then next Wednesday I will be approaching the SYE and hopefully reinstalltion when I decide what I'm finally going to do with that.

[Mudderoy]

Well as of this afternoon, the NP242 is out of the XJ. I'll be picking up an NP231 tomorrow, and then next Wednesday I will be approaching the SYE and hopefully reinstalltion when I decide what I'm finally going to do with that.

OMG open it up and tell us what is wrong with it. :popcorn:

[2000XJ]

rofl .... I will I will as soon as I get around to it. My goal is to get it driveable ASAP so that I don't miss out on some wheeling trips now through December. I also need to get a few other projects out of the way before I can occupy my bench with the tcase disassembly. My goal is to crack it open between now and next Wednesday just to have a look-see!

[Mudderoy]

rofl .... I will I will as soon as I get around to it. My goal is to get it driveable ASAP so that I don't miss out on some wheeling trips now through December. I also need to get a few other projects out of the way before I can occupy my bench with the tcase disassembly. My goal is to crack it open between now and next Wednesday just to have a look-see!

Yeah I don't blame you. Having it drivable is more important. Seeing how I have a 242, I have a vested interest in how you ****ed yours up! :smiley-laughing021:

Hey if you have the time, snap a few pictures on the swap from the 242 to the 231, or at the very least any gotchas. I know it's been put up a 100 times on other sites, but it would still be nice to have a first hand account from a board member.

[2000XJ]

I'll definately start taking some pictures... I couldn't find my camera yesterday when I was doing the removal because my g/f had it in her car. But I can snap some pics of what everything looks like without the tcase there if you'd like. I'll definately get some pics up when I do the install.

[Mudderoy]

I'll definately start taking some pictures... I couldn't find my camera yesterday when I was doing the removal because my g/f had it in her car. But I can snap some pics of what everything looks like without the tcase there if you'd like. I'll definately get some pics up when I do the install.

Sure, anything you care to share.

[2000XJ]

Little update for everyone...

Well I finally finished the HnT SYE on the "new" tcase (NP242). I went ahead and installed it on Saturday/Sunday, and then realized that I never connected the harnesses and breather tube - awesome. So Monday morning I went ahead and dropped the cross member again and reconnected the two harnesses and the breather. Today I reinstalled the rear driveshaft, made sure everything was nice and tight, filled the tcase and trans with fluid and started her up!

I was psyched! I decided that I was going to drive it to work today, and decided to take her out for a quick road test to make sure that everything was in order. Pulled out of the driveway, hit 10MPH when I started hearing a cyclical sound that increases in speed with the increase in vehicle speed (not proportional to RPMs). There weren't enough expletive smileys for what I said/felt when I heard this noise.

Pulled back into the driveway, crawl under, and see that my tcase is butted up against the trans tunnel. Crawl under the virgin '01 DD and notice that, well no $h!t, there is space between the trans tunnel and tcase." So tomorrow I'm going to swap the crossmember to a "new" one that I have that hasn't been beaten by offroad use. I'm REALLY hoping that this fixes the problem and locates the tcase to the correct location because otherwise I'm going to be out of ideas.

If you guys have any ideas as to why the tcase could be that high up, I am MORE than open to ideas. I know that it's not noise from the front DS because it's not installed. I know it's not the rear driveshaft itself because it's bolted up correctly and the u-joints are healthy. My guess is that since the tcase is pinned up against the trans tunnel that I'm just simply hearing the inner sounds of the tcase.

[muddeprived]

Little update for everyone...

Well I finally finished the HnT SYE on the "new" tcase (NP242). I went ahead and installed it on Saturday/Sunday, and then realized that I never connected the harnesses and breather tube - awesome. So Monday morning I went ahead and dropped the cross member again and reconnected the two harnesses and the breather. Today I reinstalled the rear driveshaft, made sure everything was nice and tight, filled the tcase and trans with fluid and started her up!

I was psyched! I decided that I was going to drive it to work today, and decided to take her out for a quick road test to make sure that everything was in order. Pulled out of the driveway, hit 10MPH when I started hearing a cyclical sound that increases in speed with the increase in vehicle speed (not proportional to RPMs). There weren't enough expletive smileys for what I said/felt when I heard this noise.

Pulled back into the driveway, crawl under, and see that my tcase is butted up against the trans tunnel. Crawl under the virgin '01 DD and notice that, well no $h!t, there is space between the trans tunnel and tcase." So tomorrow I'm going to swap the crossmember to a "new" one that I have that hasn't been beaten by offroad use. I'm REALLY hoping that this fixes the problem and locates the tcase to the correct location because otherwise I'm going to be out of ideas.

If you guys have any ideas as to why the tcase could be that high up, I am MORE than open to ideas. I know that it's not noise from the front DS because it's not installed. I know it's not the rear driveshaft itself because it's bolted up correctly and the u-joints are healthy. My guess is that since the tcase is pinned up against the trans tunnel that I'm just simply hearing the inner sounds of the tcase.

I am betting it's the t-case going to explode.........:D

Nah it's probably just it rubbing against the tunnel. Lower it down and see what that does. Make sure the motor mounts are good, never hurts to check. :)

[2000XJ]

Checked the motor mounts already, they actually look perfect for over 100k, and alot of wheeling hours on them. I'm impressed, surprised, and thanking God LOL

This tcase better not explode, my other one already crapped the bed, can't have this one doing it too - at least not before I sell it.

Oh, and for those who are waiting, if anyone at all, I have everything pretty well documented in photographs. I'll make sure to get them up ASAP. Just waiting for the entire process to be done.

[Mudderoy]

Checked the motor mounts already, they actually look perfect for over 100k, and alot of wheeling hours on them. I'm impressed, surprised, and thanking God LOL

This tcase better not explode, my other one already crapped the bed, can't have this one doing it too - at least not before I sell it.

Oh, and for those who are waiting, if anyone at all, I have everything pretty well documented in photographs. I'll make sure to get them up ASAP. Just waiting for the entire process to be done.

Yeah I keep checking to find out what happened to your transfer case. :popcorn:

[BlueXJ]

You did get the pump indexed correctly didn't you. If not the pump will not circulate the ATF through the system and the transfer case will starve for lubrication and cooling.

[Mudderoy]

After about 80k miles I noted a popping noise on mine. I could only hear it when I was going say 20 miles per hour or less. It was the stretched chain. I had lost most of my ATF several months prior. I think the front seal went bad and while driving at 100 mph between Dallas and Houston the small leak pushed out the ATF.

Yeah getting that oil pump hooked back up is, well I'm hoping mine is hooked up ever since I replaced the chain.

[BlueXJ]

Muddy without that pump you would be grinding the gears to dust by now. Only takes a couple hundred miles to ruin those gears.

[2000XJ]

You did get the pump indexed correctly didn't you. If not the pump will not circulate the ATF through the system and the transfer case will starve for lubrication and cooling.

School me on this Blue, you lost me. The "new" tcase has not been opened or tampered with except for the fact that I did the HnT to it - no pumps were touched or harm during this process. It is full of ATF as per the OEM specs, and not leaking anywhere.

If I'm still hearing noises after the tcase is no longer touching the trans tunnel then I will be very concerned. After taking a look at the '01 XJ, the tcase does not touch the trans tunnel, there is plenty of space between the tunnel and tcase. That seems to be issue on the trail rig XJ - it's literally hitting the trans tunnel.

The noise I am here is because it is literally stuff up against the trans tunnel.

I'm going to replace the cross member tonight and hopefully everything will be positioned correctly. However, if it's not, does anyone have any suggestions as to why the tcase would be sitting so high? Could it be installer error of some sort? Could there be a deeper issue that I'm not seeing? Could the frame/tub/both be that out of wack from wheeling?

[muddeprived]

I would think it's just your crossmember. Can you visually see it bent upwards?

It's either that....or......your jeep is folding like a taco. :rotfl2:

[2000XJ]

After further inspection the crossmember is most deifinitely bent up about .5"-1" :shocker:

My current dilemma:

I got a "new" crossmember from the same donor XJ Limited and bolt it on - it's too damn low. It's so low that I can't even get the trans to droop down enough to mount the 4 bolts in the center that hold the crossmember to the trans mount. :thumbdown:

I look at my virgin '01 XJ Limited with the same engine, trans, tcase setup. "New" crossmember doesn't look like the one on the virgin '01 XJ. Virgin '01 XJ and Trail Rig '00 both have the same original crossmember design, however the Trail Rig XJ crossmember is bent.

What crossmember was on that '98 or '99 XJ Limited that donated the NP242 to me?? It was the factory OEM crossmember I know that for a fact, but why isn't it the same as my two crossmembers on my '00 and '01. Did they change the crossmember design for '00 and '01 (I wouldn't be surprised)?? :sad0147:

[4.3LXJ]

I had mine completely apart to change the input gear. It all looked self explanatory to me. I drove it for three years, no issues.

[2000XJ]

I will be opening the old tcase eventually, I just have too much going on right now to have my trail rig be immobile, and to have a tcase occupying my workbench. I'm going to save it for a winter project when I am not in the middle of so many little things, plus an inconvienient work schedule, etc.

[Mudderoy]

I will be opening the old tcase eventually, I just have too much going on right now to have my trail rig be immobile, and to have a tcase occupying my workbench. I'm going to save it for a winter project when I am not in the middle of so many little things, plus an inconvienient work schedule, etc.

Damnit! This reminds me of Trucks! They build a 4.0L stroker, then they say they are going to dyno it and after 5 weeks of waiting they still haven't done it. :smiley-laughing021:

[alwaysxj]

Well I dug around and I couldn't find the years that the Jeep XJ Dana 30 had vacuum disconnect. I know my 1998 doesn't have it. So 1998+ do not have vacuum disconnect. I suspect the lack of vacuum disconenct goes back at least until 1997.

the vacuum disconnect was from 1986 to 1990 then they changed so this xj would not have this on the front.

[2000XJ]

Well I was able to get everything all buttoned up today. I ended up using the crossmember from the donor XJ that I got the tcase from by letting the trans all the way down, and then I put the crossmember in place and got the 4 nuts that bolt the crossmember to the trans mount a few threads on. Once I got the four nuts somewhat threaded on, I used two drifts to line the crossmember up with the holes in the frame rails so that the studs could come down through the holes in the crossmember. Once everythign was lined up I tighted the 4 nuts that hold the crossmember to the transmount and this pulled the crossmember up. Then I bolted the crossmember to the frame rails.

I'm not completely satisfied with this because it seems like everything is sitting a bit too low, but this works for now. I have the driveshafts all bolted in, and the engine/trans skid is on too. I'll try to get the tcase skid on either tomorrow or Monday morning.

A couple guys in my club have a couple crossmembers laying around so I'm going to pick those up and see if they fit better.

I'll get pics up of the swap and everything soon.

And yes Mudd, I'm trying to make this as like TRUCKS as I can!

[mopar440]

Sounds to me like something is going haywire internally... worn part is partially engaging/disengaging at will...

BTW... niether my '92 XJ Laredo (4.0/AX15/NP231) nor my current '94 XJ Sport (4.0/AW4/NV242) had vacuum disco D30... my '93 Wrangler Renegade (4.0HO/AX15?NP231) didn't either... switch must have been befoer '92... FWIW