Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: bitofaclue on September 24, 2013, 07:14:42 PM

Title: Did Jeep ever use the New Process 231 tcase?
Post by: bitofaclue on September 24, 2013, 07:14:42 PM
I'm actually looking for one for a '91 Dakota - should I be asking here?

thx.
jl
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: apeman on September 24, 2013, 07:44:30 PM
Kinda rare. They only got used in about 10 million yj, tj,xj and zj's.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: bitofaclue on September 24, 2013, 07:47:04 PM
Yeah, that sounds rough alright.  Anyone have one to spare?
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: vantagetes on September 24, 2013, 08:11:21 PM
Several issues here. You'll need to find one with the vacuum tube to control your front axle disconnect, (91 or older) and after 91 they have electric speedo hookups vs your cable. There are also two different spline counts (23 and 21 spline) and they aren't as rugged. The NP231D has a wider chain and gears then the NP231J.

Not sure about the difference in clocking. They should all bolt up (as well as the cherokee NP242J) it's just a question of maybe banging up your transmission tunnel a tad and monkeying around with shifter linkage to get the correct length.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: BlackYJ on September 25, 2013, 11:59:50 AM
Not sure about the difference in clocking. They should all bolt up (as well as the cherokee NP242J) it's just a question of maybe banging up your transmission tunnel a tad and monkeying around with shifter linkage to get the correct length.

The clocking comes from the transmission and not from the t-case.  The XJ t-cases hang lower than YJs
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: JENSSEN on September 25, 2013, 08:55:52 PM
Think I have a vacume one kicking around
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: bitofaclue on September 26, 2013, 09:20:44 AM
Several issues here. You'll need to find one with the vacuum tube to control your front axle disconnect, (91 or older) and after 91 they have electric speedo hookups vs your cable. There are also two different spline counts (23 and 21 spline) and they aren't as rugged. The NP231D has a wider chain and gears then the NP231J.

Wow - this is the kind of detail I need.  Thanks for wading in.

What I have is a 231D, and I assume the spline count you're referring to is the input (transmission) shaft.  If so, mine is 23.  The output (driveshaft) is 26 splines, if it matters/differs.

There's a little adapter on the speedo output that has a wiring connector in addition to the speedo cable - I assume that's for the cruise control.

Quote
Not sure about the difference in clocking. They should all bolt up (as well as the cherokee NP242J) it's just a question of maybe banging up your transmission tunnel a tad and monkeying around with shifter linkage to get the correct length.

What do you mean by "clocking"?  I don't think I've heard the term before.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: bitofaclue on September 26, 2013, 09:27:29 AM
Think I have a vacume one kicking around

I just dropped you an email.  I'd really appreciate your checking and seeing if you have one available.

thx.mch.

Jonathan

Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: cLAY on September 26, 2013, 10:04:02 AM
Clocking refers to what angle the t-case bolts onto the tranny. The bolt pattern is rotated differently on some vehicles so that the t-case hangs down lower. Shouldn't be an issue for you since the tranny sets the indexing, the t-case patterns are the same.

You can also use a non-disconnect vacuum t-case by just plugging the lines and then removing the vacuum shift motor in the front diff and shimming the fork over so it just stays in the locked position permanently.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: bitofaclue on September 26, 2013, 10:22:18 AM
Clocking refers to what angle the t-case bolts onto the tranny. The bolt pattern is rotated differently on some vehicles so that the t-case hangs down lower. Shouldn't be an issue for you since the tranny sets the indexing, the t-case patterns are the same.

Ah, okay, I get it.

Quote
You can also use a non-disconnect vacuum t-case by just plugging the lines and then removing the vacuum shift motor in the front diff and shimming the fork over so it just stays in the locked position permanently.

Is there any downside to doing this?
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: cLAY on September 26, 2013, 11:12:30 AM
Front axle gears and front driveshaft will spin all the time. Sounds worse than it is. Most Jeeps(since mid 90s) and 4x4 trucks made today do not use a disconnect system and have no issues.

Most older Jeeps that have the system are starting to break down. Failed switches, vacuum leaks, moisture in the shift motor that freezes in winter are common problems that prevent 4wd engagment. After having all the above issues on my '89 XJ  I just locked the front diff in all the time and was much happier.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: Sean778 on September 26, 2013, 12:19:26 PM
I think the guys at Broken Axle had a used t-case from a Durango kicking around at one point.  I don't know if it would work or not, but it would be worth looking into for sure.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: BrokenAxle on September 26, 2013, 05:49:28 PM
Yes, we have a 231HD from a durango here.  It doesn't have any of the vacuum stuff on it.  Shoot me a pm or call me at the shop if you are interested!

Thanks
Dave
403-237-7706
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: hps4evr on September 26, 2013, 08:47:53 PM
Front axle gears and front driveshaft will spin all the time. Sounds worse than it is. Most Jeeps(since mid 90s) and 4x4 trucks made today do not use a disconnect system and have no issues.

Most older Jeeps that have the system are starting to break down. Failed switches, vacuum leaks, moisture in the shift motor that freezes in winter are common problems that prevent 4wd engagment. After having all the above issues on my '89 XJ  I just locked the front diff in all the time and was much happier.
Sadly last I read dodge will be going back to a disconnect type front axle on 2500-3500. Not sure if it's vacuum actuated or what, but looks similar to the old designs... I guess anything to gain a little efficiency...
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: cLAY on September 27, 2013, 12:11:41 PM
I wouldn't mind having it back actually.  2wd low when backing up a trailer is pretty sweet. I'd like to see locking hubs back like the Superdutys. Leave it in if you want, unlock it when you want.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: bitofaclue on October 02, 2013, 04:46:07 PM
Think I have a vacume one kicking around

Were you able to confirm this one way or the other?  I dropped by Broken Axle this morning, and the 231D HD they have is completely different from my 231D, so I'm still on the hunt.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: JENSSEN on October 02, 2013, 09:44:11 PM
The only vacuum 231 I have:

(http://i651.photobucket.com/albums/uu235/RACE4THECURE/3407CC13-CFF9-486C-A307-1FCD21C0E537-6325-0000050B856B9004_zps4f287292.jpg) (http://s651.photobucket.com/user/RACE4THECURE/media/3407CC13-CFF9-486C-A307-1FCD21C0E537-6325-0000050B856B9004_zps4f287292.jpg.html)

(http://i651.photobucket.com/albums/uu235/RACE4THECURE/0B25C420-E125-4824-87BC-1FCA81FD6A46-6325-0000050B8D45CF03_zpsb8c66cc7.jpg) (http://s651.photobucket.com/user/RACE4THECURE/media/0B25C420-E125-4824-87BC-1FCA81FD6A46-6325-0000050B8D45CF03_zpsb8c66cc7.jpg.html)

(http://i651.photobucket.com/albums/uu235/RACE4THECURE/1122850D-84C1-4BEF-8647-BFC5D4F5CA3B-6325-0000050B9443788B_zps51a73b50.jpg) (http://s651.photobucket.com/user/RACE4THECURE/media/1122850D-84C1-4BEF-8647-BFC5D4F5CA3B-6325-0000050B9443788B_zps51a73b50.jpg.html)


have a few other t-cases floating around
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: bitofaclue on October 03, 2013, 05:32:08 AM
That looks like it (the vacuum port and speedo takeoff are in the right places, unlike Dave's), but I have no idea what the difference(s) is/are between a D and an AMC.  Would it be possible for me to come by, take a closer look, and compare?
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: JENSSEN on October 03, 2013, 10:00:35 PM
Nice meeting you ! Sorry I couldn't help ,.. damn input shaft length! looks exactlly the same but alas,...
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: bitofaclue on October 09, 2013, 02:29:08 PM
Nice meeting you ! Sorry I couldn't help ,.. damn input shaft length! looks exactlly the same but alas,...

Yes, good to meet.  And thanks for spotting that trans/tcase on kijiji - I snagged them from him and
the tcase is bolted up.  Now...

I broke off one bolt on the rear diff u-joint yoke.  Yoke came off okay and I managed to drill and pick
out most of it (just couldn't get an extractor to turn it out), but there's still some left that I think I
should be able to chase out if I can find the right tap.  Since I can't spot my thread gauge, can anyone
tell me what the size & thread are?  And where's the best place for taps around town these days?  I've
always like dealing with Triad, but something down south would be nice so I don't have to go way the
hell up there.
Title: Re: Did Jeep ever use the New Process 231 tcase?
Post by: JENSSEN on October 13, 2013, 09:59:42 AM
Use one of the bolts to figure out the threads, I work at Acklands and we have tons of taps, just message me what you need