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AX15 trans to NP231 tcase seal?

desertjr

NAXJA Forum User
Location
Low Desert
I've got a leak between me 1990 ax15 & np231. I've seen both gear oil, and ATF which mean both have leaked out.

So I need the seal or seals to be replaced and make things all better:) any help here fellas?
 
Re: Trans to tease seal?

There is a weep hole between the transmission and transfer case that will let gear seep out when the transmission output seal is beginning to fail. The transmission seal rides in the adapter to the transfer case and seals on the input shaft to the transfer case. You need to pull the transfer case out in order to change the seal. As far as the transfer case leaking, your going to need to clean everything underneath in order to figure out where the leak is coming from. It could be leaking from any number of places.
 
Re: Trans to tease seal?

Oh it's all from the uninion where they meet. Ill be doing a flt belly soon which is why I'm asking cause I'm pulling hem both out already:)
 
Renamed for you, I hate autocorrect :thumbup:

The transmission output seal is 8350 3108 from the dealer (some parts houses can cross-ref this) and the transfer case input seal is actually different depending on what exact transfer case you have. It is J535 9457 with an 87-90 A/B/C case or 4167 929 with a 90 K case.

"A" cases: transfer case tag has part number 5300 3927, 5300 4271, 5300 4272, 5300 4301, 5300 4328, 5300 5355, or 5300 5382. All in XJ/MJ vehicles with transmission serial numbers up to 131163.

"B" cases: tag has part number 5300 6094, 5300 6095, 5300 6096, 5300 6191. XJ/MJ transmission serial numbers up to 131163.

"C" cases: tag has part number 5300 6093, 5300 6095. XJ/MJ transmission serial numbers up to 131163.

"K" cases: tag has part numbers 5300 8207, 5300 8208, 5300 8209, 5300 8210, 5300 8211, 5300 8212. XJ/MJ transmission serial numbers up to 131163.

Other wonky splits based on transmission serial number are different if it's out of a YJ, and there's no real mention of what happens if it's a transmission serial number 131164 or higher. I Blame AMC.

Oh, and there's about another half dozen lettered transfer case variants (D-J and L-O) that were used in other combinations. I'm glad Chrysler took over, the 91 and later parts application info is nowhere near this confusing. It lists applicable transfer case part numbers right in the same line as the part you're looking at and none of it depends on serial numbers of other parts in the vehicle.

I'm guessing this all has to do with the 21 to 23 spline changeover or long vs short NP231 input gears but I'm not sure why that would affect anything with an AX15, since I was pretty sure all AX15 vehicles were 23 spline even in the late 80s.

If you go with a local parts house instead of buying it through the dealer, and there are more than one option available for the transfer case input seal, I strongly recommend buying both as they're fairly cheap. Use the one that fits, return the other. Also, if you go with a local parts house for the transmission output seal, make sure to say it's for the 4x4 adapter housing, NOT anything about the transmission output, or the parts counter monkey may get confused and give you a rear output seal for an NP231 instead. Don't ask how I know this... if you want to double check, just make sure it doesn't have a metal shell around it, the AX15 rear output seal is just a little rubber/plastic one with a few lips instead of having a metal outer shell that presses into something.
 
Thank you for that sir:) Oh jeez ok my trans IS from a Yj, tcase as well. I was told 90, but I'm not certain at all.
The tag reads 231j, 5300, 6096, 5 18, 89 2 & 272. There's a cast on the tcase that reads, c-16117 & 09104. Pics on the way.
 
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Tag
image_zpsae3efdc9.jpg


Cast numbers just above speedo cable.
image_zps29b487f2.jpg


Other cast marks just below tail cone/housing. Read 89 & 90.
 
OK, I'm going to assume a '90 YJ trans and tcase. 5300 6096 is the part number, 272 is the gear ratio (2.72:1 low range), dunno what the others are but probably manufacture dates or something.

C-16117 is cast in so it's just a casting number or something, not sure where the serial number actually is on AX15s because I saw all this confusing info, threw my hands up, and said "I'm getting a 90s AX15 this shit is confusing" when I went to do my swap. The serial number break for YJs is apparently 131001, everything else I listed is the same - A/B/C/K specs and part numbers, that is.

edit: your transfer case part number is in the B group, so I believe you need a J535 9457 seal. Not 100% on that... probably 90% confidence.
 
I'm sure ill bump this mid next week or the week after when I start on my flat belly. grab pics of both of them and get the correct seals.

Last question for now is what's the top 2 bell housing bolts? My jeep DOES NOT have them installed currently. So I was gonna go grab 2 bolts from the hardware store but what's there head pitch & length?
 
Thread pitch is 3/8-16, factory length is 1 7/8" but a 2" long one with a flat washer and cut lockwasher fits perfectly. I'd strongly suggest grade 8 for at least the flat washers, torque spec is 27 foot pounds for the top two (3/8" shank) and 43 foot pounds for the bottom two (7/16" shank.)
 
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