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Jeepster19
02-01-2015, 04:09 PM
Anyone out there know what years the Np231 will fit.I have a 98 and I'm going to put a SYE in mine but I don't want any down time so I'm going to take a trip to the pick and pull and get one if its not too expensive.:xj-black:
bluedragon436
02-01-2015, 04:33 PM
Anyone out there know what years the Np231 will fit.I have a 98 and I'm going to put a SYE in mine but I don't want any down time so I'm going to take a trip to the pick and pull and get one if its not too expensive.:xj-black:

Was kind of thinking the same thing, to help with down time.. Going to be taking my 97 down for a bit so I can do the lift revamp/upgrade including the LA upgrade.. So figure if I can pick up another TC that I can go ahead and do the SYE install and maybe even the chain/and planetary upgrade.. then have my current 97 TC to have as a spare...
Jeepster19
02-01-2015, 05:10 PM
Was kind of thinking the same thing, to help with down time.. Going to be taking my 97 down for a bit so I can do the lift revamp/upgrade including the LA upgrade.. So figure if I can pick up another TC that I can go ahead and do the SYE install and maybe even the chain/and planetary upgrade.. then have my current 97 TC to have as a spare...

What's the cost on the chain and planetary upgrade?
bluedragon436
02-01-2015, 05:16 PM
It all depends on where you go for the parts.. If you are looking for new, you can go through JB Conversions you're looking at $350 for the chain upgrades, and another $250 for the 6 gear planetary upgrade.. If you look on Ebay there is a guy PowerTrainPartsPlus (http://stores.ebay.com/powertrainpartsplus/), and you can get the chain upgrade of roughly $150 and the 6 gear planetary upgrade for about $130.. and he does free shipping... Another thing you can do is pick up parts out of JY TC's I'm looking at ordering everything through PTPP on Ebay, as I can't really afford the $600 right now for all new parts..
autotech98
02-07-2015, 05:52 PM
Doesnt the 231 have two different spline counts?? I beleive someone mentioned that before ...but i could be wrong
bluedragon436
02-07-2015, 06:04 PM
The 231 from a Pre-90 has a short 21 spline input, from a post 90 has a medium 23 spline input
autotech98
02-07-2015, 06:06 PM
Cool...thought there was a difference. Thanks james
bluedragon436
02-07-2015, 10:25 PM
Cool...thought there was a difference. Thanks james

No problems.. I was looking at picking up another TC to rebuild/upgrade and install my SYE so it can be ready to install into my 97 when I do the LA crossmember install.. And thought if I could just pull my TC out of the 90 then I'd be a step ahead.. but I thought I remembered reading online there was a difference.. just couldn't remember what the differences were.. I might still pull the TC before it finds it's way to the JY so I will have a spare TC.. will just have to swap the input shafts from my 97 if something happens to the 97's TC (so long as the input shaft is still in good shape that is)...
autotech98
02-07-2015, 10:33 PM
I hear that.cheaper to swap shafts than buy a new one
bluedragon436
02-08-2015, 02:17 AM
I hear that.cheaper to swap shafts than buy a new one

Yeah I'm sure it is.. like I said.. will probable just pull the 90's TC to have as a spare for the 97, and just do the SYE install and such while I'm doing the crossmember install.. especially since I'll need to go to the front shaft in the rear for a bit anyways, due to the higher lift height...
prcjeep
02-08-2015, 10:44 PM
IIRC the np231c (ours is 231j) has the 6 gear planetary gears and heavier duty chain. They come out of chevy but I can't remember which ones. You can't use the case though as its mounting bolts are clocked differently
bluedragon436
02-08-2015, 10:59 PM
IIRC the np231c (ours is 231j) has the 6 gear planetary gears and heavier duty chain. They come out of chevy but I can't remember which ones. You can't use the case though as its mounting bolts are clocked differently

Nope.. you grab the wide chain and necessary gears from the 231C and the 6 planetary gear set from a 241D HD... Or you can look on Ebay and there is a seller that sells the HD chain upgrade and the 6 gear planetary set for a fairly decent deal shipped.. thinking about seeing if he has the proper input shaft for my 97 that I can pick up as well.. that way I can take my 90 231J and just get it cleaned up and ready to install w/ all the upgrades
autotech98
02-08-2015, 11:30 PM
Oh the things we go through to modify our xjs.
bluedragon436
02-08-2015, 11:34 PM
Oh the things we go through to modify our xjs.

For me it's just to upgrade her and make it a smoother transition in that process.. I'd rather have the TC ready to go when I pull the stock crossmember, and then have the current TC out of the 97 to keep as a spare..
autotech98
02-08-2015, 11:47 PM
Oh i agree..but why not build it beefier if your gonna do it.. right?
bluedragon436
02-09-2015, 12:20 AM
Oh i agree..but why not build it beefier if your gonna do it.. right?

Yep pretty much... figure was going to be installing my SYE I had purchased for the 98 anyways, so might as well go for a HD chain upgrade and the 6 gear planetary while I got it all apart... Can't afford a Rubicon TC or an of the nice beefy rock crawler style TC's.. maybe one day, but for now I'll beef the 231J up as much as I can..