NP231 starting to go...... what to do?

[alosix]

Ahemm...What about a 96 231? It uses the same t-case output as the 97+ XJ, and other than the shifter mech they're the same as the TJ...

Auto XJ case is NOT quite the same as a TJ case. The XJ AW4 requires a short input shaft. TJs tend to have the long shaft. Otherwise they are the same and interchangable.

FWIW, what exactly is wrong with your case? Where is it leaking from? This could be a result of the SYE installation (bad seal on reassembly). You might just need to take it apart again and re RTV it.

231s are a really simple setup. I had mine completely torn apart and reassembled in about 1.5 hours (changed SYE to super short SYE and swapped the input gear.). If you did an SYE then you've taken it more than 1/2 way apart already. 4 more bolts and one lock ring and it willl fall completely apart.

Jason

 

[alosix]

ok, called few places, my mech got me a deal for 1200$ cdn... heh...
called some other places... around 1400$ are they out of their fawking minds?
Called a local Jeep shop (Jeep Thrills) they said, bring it in, 400$ will fix it. So i decided to call JB Conversions and get the full rebuild kit take it out, open it and see what is fawked and do it myself. Ordered that kit and they said 5 days. Spoke to John, very nice guy. Anyway, something leaks as well, the problem is, that my Crossmember is CLEAN, but its also soaked in ATF... my Tranny pan is clean as well, dirty but it does not have any ATF on it. and my Tcase has red fluid where the crack on it is(where it splits) like drips... so im thinking wtf... where too look? take of the t case.. and then what? how to determine if that leak was from the Tcase or Tranny?(auto). Can i put my jeep into D and see if it leaks with all the crap disconnected?(ie. DSs Tcase etc?)

Because i cant really see where it leaks! i checked both tranny and Tcase fluid, but i would say, Tcase since its fawking HOT and noisy!!! Also could that be something to do with SYE installed? had it done two-three months ago. Its a AA thing.

The tranny really can't leak in too many places. If it is leaking it would most likely be the rear output seal by what you have described. You'll be able to tell this when you pull the t-case out. Front of t-case should be pretty dry, but it its covered in ATF then its time for a new output seal on the tranny.

Your leak does really sound like the t-case wasn't RTV'ed very well when the SYE was installed. I'd pull the case halves apart and reseal them to call it good.

Running it with the t-case out will most likely get fluid everywhere. The t-case input shaft is what seals the rear of the trans. with out it there is a gap between the trans output shaft and the seal.

Jason

 

[MachineMan]

You can buy parts or rebuild kit for the NP231 at www.rubicon4x4.com. I got the master kit for mine and replaced all the bearings, shift pads, and oil seals in about 4 hours (not including TC removal). The kit doesn't come with any gears, chain, or speedo housing seals.

You will need a lock ring plier and a seal puller would also help.

 

[Purple]

so if i pull the Tcase, will all the atf leak out of AT>? how hard is it to change that rear seal on the tranny?

 

[MachineMan]

The rear seal on the tranny is easy to change once you get the TC off. You can pry it out around the trans output shaft. If your trans is sitting level no fluid should come out, at least mine didn't.

 

[Purple]

thanks a lot for that pic

 

[dizzymac]

Are you sure its the TC....mine was making all kinds of noise too, but in the process of changing out the TC we discovered that it was really the flywheel making all the noise, it was cracked all to hell. replaced it and all was good, replaced TC too seeing as a so called mechanic had changed the fluid w80-90 gear oil. Good luck.

 

[Purple]

i dont know, i removed the FDS and it was still making all these noises and vibes... took it to a mechanic, they said its the TCASE. So i assume its the case, if you say its the flywheel... is there a way to check that without removing the tranny? how did you find out?

 

[dizzymac]

Drop the flywheel cover...mine was so bad that you could see the cracks...but if you can't see any ( they'll most likely be around the mounting bolts on the crank) you can use a pry bar or long screwdriver to pry on the flywheel to get it to flex and see if there are any cracks, manually rotate the engine and check all around the bolts for cracks. It goes without saying....use caution and be careful. Hope for the flywheel, its a lot cheaper than a TC. Good luck.