Transfer Case Rebuild Confusion

[peoplethatcant]

I'm currently rebuilding my tcase NP231J on my 04 TJ sport with a 42RLE auto trans and am a little confused about which parts to order.

-It's got a 16mm (Narrow, 6010N) input bearing, with a 23 spline shaft
-It's got an SYE kit that the PO installed, and based on snout markings and images, it looks to match the ProComp 4007 SYE that is listed for pre-95 231s
-The main shaft's mode shift synchronizer (the gear that spins free in 2wd and gets locked to the drive gear in 4wd) has 2 roller cage bearings inside it
-There is a metal shim ring in front of the drive gear on the main shaft
-There was a splined rubber gasket on the rear output, which appears in old rebuild kit images but not new

As far as I can tell, the 2 cage bearings in the synchronizer and the splined rubber only show up in the wide bearing rebuild kits from older 231s. The metal shim (that shows some gear teeth wear marks) only exists in this specific SYE kit from what I can see, which ProComp doesn't appear to sell or list parts for.

So I'm hoping someone might have experience in this franken-t-case type scenario and point me in the right direction.

Were there 231s made with different styles that mixed and matched bits like this? Or did the PO just take the stock 231 and put in an older style SYE that came with caged bearings? I'm just not familiar what else changed between the two versions.

Can I order the old-style wide bearing rebuild kit to get the caged roller bearings, splined shaft rubbers, etc and still have everything but the input bearing fit? And then just order a replacement 6010N?

Any help is greatly appreciated, especially since I opened this thing up because of a rhythmic rubbing noise and it all looks to be in spectacular condition inside except for the metal shim from the SYE kit. So I do want to replace every wear item and not risk having the sound remain.

 

[Woodrow]

IDK but @NovakConversions might be helpful?

 

[macleanflood]

Also don't assume that's the original transfer case...

-Mac

 

[peoplethatcant]

Also don't assume that's the original transfer case...

-Mac

Definitely not haha, I'd say coin toss.

 

[peoplethatcant]

Well shipping to Canada takes long enough, I figured I'd pull the trigger and hope I can sort any mismatches locally. I went with a <94 rebuild kit, a >94 input bearing, chain, and mode selector fork as no one seems to sell the right plastic inserts and it was cheap, and an output shaft seal that is supposed to fit most SYE's.

Fingers crossed. Once I figure out what works, if anything seems relevant to the next guy I'll post up some photos and part numbers.

 

[NovakConversions]

Well shipping to Canada takes long enough, I figured I'd pull the trigger and hope I can sort any mismatches locally. I went with a <94 rebuild kit, a >94 input bearing, chain, and mode selector fork as no one seems to sell the right plastic inserts and it was cheap, and an output shaft seal that is supposed to fit most SYE's.

Fingers crossed. Once I figure out what works, if anything seems relevant to the next guy I'll post up some photos and part numbers.

As you get into rebuilding it, let us know if you run into issues. If you call in and ask for Jeff Smith or use his extension 350. If he can't help, we will get you directly with our rebuild shop.

-Dustin

 

[peoplethatcant]

Well for anyone that stumbles across this thread down the road, I can confirm that the bearings and seals from the older style cases with the wide bearings do all fit nicely if your SYE shaft is of the older style with caged bearings. The rear SYE output seal and input bearing were the only two things I had to get additionally.

I can also confirm that if everything in the transfer case looked perfect and fresh and new, that sometimes the sound wasn't coming from the tcase at all, and mechanics with stethoscopes can be mistaken.

 

[thedustyboot]

good information to keep in mind as i tear into a tcase rebuild and i dont know the year of jeep it came out of..