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Unread 04-05-2013, 07:35 PM   #1
Line58
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YJ NP231J in TJ

Has anyone here installed a YJ transfercase in a TJ? If so, what did you do about the tcase shift linkage? Can the YJ linkage be used (nice and simple) on a TJ? Can the TJ linkage
be modified to accommodate the YJ case?

In using a 1994 YJ case that came with the AX15 I'm swapping in.

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Unread 04-05-2013, 11:59 PM   #2
Line58
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I now have the transmission and tcase in. The YJ linkage isn't going to work. Is their a way to modify the TJ trans shifter? Would a cable shifter fix this?
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Unread 04-08-2013, 10:31 PM   #3
alloutbmx
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I'm running one. Pretty sure we took all the yj shift lever off and just hooked the tj stuff right to it. I don't remember any issues
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Unread 04-08-2013, 11:13 PM   #4
Knuckelhead
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Pre 1995 YJ NP231 transfer cases don't have a true neutral:
http://www.pirate4x4.com/forum/jeep-...-np231-tj.html
" '94-and-earlier NP231s don't have a true Neutral position for trouble-free towing. When in Neutral, the input gear of the 231 separates from the front and rear output shafts, but the shafts are still connected. A special sector (available from JB Conversions) solves this problem. With a true-Neutral kit, the rear driveshaft spins independently of the rest of the drivetrain. Since the T-case oil pump is driven by the rear output shaft, lubrication of the T-case isn't a problem."
http://www.jpmagazine.com/howto/5449/index.html
...
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Unread 04-08-2013, 11:35 PM   #5
Anticanman
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I have a TJ case in my Yj and sold my Yj case to a guy with a TJ.
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Unread 04-09-2013, 02:54 PM   #6
Line58
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Quote:
Originally Posted by Knuckelhead View Post
Pre 1995 YJ NP231 transfer cases don't have a true neutral:
http://www.pirate4x4.com/forum/jeep-...-np231-tj.html
" '94-and-earlier NP231s don't have a true Neutral position for trouble-free towing. When in Neutral, the input gear of the 231 separates from the front and rear output shafts, but the shafts are still connected. A special sector (available from JB Conversions) solves this problem. With a true-Neutral kit, the rear driveshaft spins independently of the rest of the drivetrain. Since the T-case oil pump is driven by the rear output shaft, lubrication of the T-case isn't a problem."
http://www.jpmagazine.com/howto/5449/index.html
...
As I don't tow the Jeep that shouldn't be a problem. That said, when/if I ever pull the case apart for a HD conversion I'll have to install one of those.
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Unread 04-09-2013, 02:59 PM   #7
Unlimited04
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the input shaft spline geometry on the 94 & earlier is different than the 95 & up. the input shaft depth is also different IIRC. call JB conversions for more info...pretty sure you'd need to swap to the new-model input shaft.
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Unread 04-09-2013, 03:06 PM   #8
Line58
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Quote:
Originally Posted by Unlimited04 View Post
the input shaft spline geometry on the 94 & earlier is different than the 95 & up. the input shaft depth is also different IIRC. call JB conversions for more info...pretty sure you'd need to swap to the new-model input shaft.
Thank you for that input, I didn't know that!

I'm doing a AX5 -> AX15 conversion using the Dakota bellhousing and YJ AX15/NP231J. As the trans and tcase are both from the same vehicle I should be fine. That said, I'm finding plenty of other areas where things don't seem to add up (tcase shifter, 4x4 indicator, speedo plug, trans support not lining up with skid plate, etc).
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Unread 04-09-2013, 04:29 PM   #9
Anticanman
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The indicator is easy enough. All the info you need is right here:

http://www.jeepforum.com/forum/f12/t...80/?highlight=

Just pick and choose which pieces you need to install. You may also run into a problem with the speedometer but I think that's been mentioned. Electric vs manual cable.

Edit: Nevermind on the speedo, its the same more or less.
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