NP 231 question - Off-Road Forums & Discussion Groups
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post #1 of (permalink) Old 10-12-2000, 08:53 PM
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NP 231 question

I need to change out the 21 spline input gear and replace it with a 23 spline gear. Anybody done this?
How difficult is it?
Any special tools needed?
Should I do it myself or have a shop do it?
Are there other thing to check for while the case is open?
The transfer case is out of the Jeep already. Any advise would be appreciated!!

Lowrange
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87 Wrangler, 4.2L, HEI, BA-10/5 (but not for long), Procomp lift, Procomp 3000's, Superwinch
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post #2 of (permalink) Old 10-13-2000, 10:28 AM
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Re: NP 231 question

Has anyone else done this?

Lowrange
Email: [email protected]
87 Wrangler, 4.2L, HEI, BA-10/5 (but not for long), Procomp lift, Procomp 3000's, Superwinch
post #3 of (permalink) Old 10-13-2000, 11:32 AM
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Re: NP 231 question

I hate to see someone's question go un-answered, but I'm afraid I may not be of much help.
I've opened up my NP231 when I installed a slip yoke eliminator about a year ago.
Even though I had to split the case and got to see the main shaft in particular.
I didn't look at it close enough to see what would be involved with replacing the input section.
My guess is that some press work may be required.

One word of advice I can give you is to be real careful lining things up.
Some covers have oil passages that need to align.
Know in advance that the oil pump is a bit of a pain to get into position when you re-assemble it.
I may not have helped much with content, but at least I got your question back on top. [img]/wwwthreads_images/icons/wink.gif[/img]
Best of luck.
-Gus-

90YJ 4.2L NV4500 456:1 33's Twin ARB's
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post #4 of (permalink) Old 10-13-2000, 11:48 AM
 
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Re: NP 231 question

Ive done it 3 times(torn apart the T case) once to install the Tera Low Kit, once to go from 21 to 23 spline(engine swap), and once to go from 23 to 21 spline(engine swap). I have some pretty detailed instructions that came with the Tera Low kit. But any good shop manual will work. Ill dig up my Tera Kit instructions now that Im getting some of my files reorganized again. If you need me to fax the Tera directions, I'd be glad to, let me know.

Jeff
89 Wrangler
I take my Jeep "On the Rocks",usually "With a Splash of Addrenalin"
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post #5 of (permalink) Old 10-13-2000, 12:12 PM
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Re: NP 231 question

Thanks Gus & Jeff.
Yes Jeff, I would like to see the instructions. Check your email.
Thanks,
Butch

Lowrange
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87 Wrangler, 4.2L, HEI, BA-10/5 (but not for long), Procomp lift, Procomp 3000's, Superwinch
post #6 of (permalink) Old 10-14-2000, 11:59 PM
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Re: NP 231 question

The shop manual is posted at http://www14.brinkster.com/yjwrangler/




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post #7 of (permalink) Old 10-16-2000, 11:34 AM
 
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Re: NP 231 question

I got nowhere from that link...

John
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post #8 of (permalink) Old 10-16-2000, 01:13 PM
 
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Re: NP 231 question

One word of caution on the input gear replacement. The auto trannies used the LONG gear and the stick trannies used the SHORT gear. Be sure that the one you use is the right size for the tranny you are going to use. Other wise a short gear in a auto tranny will FIT but the seal will not engage the shaft.
GP'n

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post #9 of (permalink) Old 10-16-2000, 06:01 PM
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Re: NP 231 question

http://www14.brinkster.com/yjwrangler/



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