04 231 install in my 90 XJ AW4

Finally getting around to installing a 04 TJ 231J in my 90 XJ with an AW4 trans......Here is my probs,first the 04 231J is out of an Auto TJ,which the input gear is longer and 23 spline..no biggie...so I order a 91 XJ 231J 21 spline input as they list 23 spline and 21 spline for that year 231J and this is the last year they do ask for 21 or 23 spline and my 90 XJ uses the 21 spline..........so happy me tears down the 04 231J and try to install the 21 spline input gear....does not fit the plantery,same teeth count,but the 21 spline input gear,the outer teeth that rides inside the plantery set are not cut deep enough..so it does not fit inside the planet carrier....So I have a junk 96 231J and rip it down to see if the planetery is different then the 04 231?..well the same...ratts...to make a long story short,what part numbers do I need to install a 21 spline input gear into a 96 and up 231j?.....Do I need the early planeterys and anulus gear to match the 21 spline?..or is thier some super secret 21 spline input gear that drops into the 96 up 231J t cases?....................Thanks,

Rags :wave:

I just swapped in a '95 AW4 into my '90. I had to change the tranfer case input shaft same as you except I was keeping the stock '90 NP231. Here's a site with some good spline info.

http://www.novak-adapt.com/knowledge/np231.htm

You will need the short shaft 23 spline but the gear cut as you stated is the issue. Not sure about an '04 NP231...

Thank you very much aperwork .............I found what I need on the Novak Site!!......21 spline
Short length, narrow bearing, late planetery gear cut input gear 231J.....

Will call on Monday and see what the damage is...By chance could you tell me how much you input gear was so I have an idea?...My factory one I just bought for a 91 231J 21 spline was 98.00 bucks my cost at work...will be sending it back..............

Thanks,
Rags :wave:

MachineMan said:

I just swapped in a '95 AW4 into my '90. I had to change the tranfer case input shaft same as you except I was keeping the stock '90 NP231. Here's a site with some good spline info.

http://www.novak-adapt.com/knowledge/np231.htm

You will need the short shaft 23 spline but the gear cut as you stated is the issue. Not sure about an '04 NP231...

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You might want to think about selling the '04 TC. They bring quite a bit of money. $400-600. I think '01 and up have a balancer or vibration dampner on the rear shaft. Something to think about. I would build up the '96 and try sell the '04.
Tom

I would build the 96 t-case I have for parts,but it is junk,broken case,wasted chain etc....the 04 TJ t-case looks like a 96 up,no damper....just the input gear is different and has real low miles on it..and it was free ....


Rags

75SV1 said:

You might want to think about selling the '04 TC. They bring quite a bit of money. $400-600. I think '01 and up have a balancer or vibration dampner on the rear shaft. Something to think about. I would build up the '96 and try sell the '04.
Tom

Click to expand...

Still, If the '04 is still in one piece you could try and sell it for minumum $400. Then buy a good 91-00 T/C for about $250. Something to think about. I had a '00 T/C sold, but the guy needed the newer style. He looked at swapping shafts etc., but didn't think it was worth it. Try Car-Parts.com and check out junkyards in your state or region for prices.
Tom