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'96 NP231 Mystery

zemsten

NAXJA Forum User
Location
USA
Hey all. I'm working on my 1996 XJ, all stock. The rear output shaft seal has a terrible leak, so I decided to replace it. I pulled everything apart and went to pick up a new seal, and I've found two seals now that are specified, and neither fit. They both have an OD that's smaller than my bore. Could this be because the tail extension housing I have is different than a typical 96? It's the external slipyoke kind, that's sealed. Additionally, when I stuck my head up there to take pictures, I found this broken washer, or circlip or something. What is that? I removed the lock ring behind the washer, in front of the seal. This was behind the seal and is just sitting in the bore.
Dji7nCE.jpg
 
Thanks for the link. That c-clip labeled "Rear bearing I.D. retaining ring" appears to be the one that is broken for me. I couldn't find a good exploded view labeling that before. All the typical ones show each component group separately and don't include a lot of the small parts. Thank you!

Separately, even when I look up parts for a '97 XJ, I get the same results. The two seals I've gotten so far are 4370N, which I believe is the seal for an internal slip yoke, with the long tail shaft housing; and a 4813, which appears to have the right I.D., but the O.D. is still too small. Do you happen to have a part number for this other seal?

I'm considering just doing a SYE now, as I'm going to lift it 4" and will probably need one eventually. I just wanted to have it driveable for a little while, while it was at stock height too.
 
Thanks for the link. That c-clip labeled "Rear bearing I.D. retaining ring" appears to be the one that is broken for me. I couldn't find a good exploded view labeling that before. All the typical ones show each component group separately and don't include a lot of the small parts. Thank you!

Separately, even when I look up parts for a '97 XJ, I get the same results. The two seals I've gotten so far are 4370N, which I believe is the seal for an internal slip yoke, with the long tail shaft housing; and a 4813, which appears to have the right I.D., but the O.D. is still too small. Do you happen to have a part number for this other seal?

I'm considering just doing a SYE now, as I'm going to lift it 4" and will probably need one eventually. I just wanted to have it driveable for a little while, while it was at stock height too.




I should've also added in this last message that the t-case has a manufacture date of 11/95, so it shouldn't be the newer style I don't believe.... I have seen some literature, such as Iron Rock Offroad's website, that says the '96 and newer has the sealed style tail shaft extension.
 
I have an 88 and a 94 XJ, both with 242s, so my knowledge of yours is limited. I use RockAuto for almost all my troubleshooting efforts. I looked up a 96, which does list the 4370N, and by clicking on the part number, it brings up the years and models that used it. Seeing that it stopped at 96, and knowing that the later models had the bellows seal, I pulled up a 99 and noticed that the OD of the seals for that year where slightly larger than for the 96, thus my suggestion to take a look at those years. It's listing Timken 710663 for the 99.

While a "shorty" SYE will replace all these parts we're discussing, a H&T on these later models doesn't affect the seal, it's all external to the case, unlike the earlier models. There's limited benefit to a full blown SYE on a late model 231 in an XJ. Significantly more torque/HP, extreme lift, short wheelbase (Wrangler), it would have it's benefits, but relative stock under the hood, reasonable lift height (4-8") in an XJ, your money may be better spent elsewhere, IMO... A H&T can be done now or later, I guess it depends on whether you were planning to use lathe or doing it in-vehicle...

If you know what parts to keep paired up (gears for example because of the angle change), you can put any internals with any year case with any year output extension housing... The tag is a good starting point but at the end of the day you have to work with what you have..
 
Fantastic! I am new to this forum as a poster, but have been reading for quite some time now, and I continue to be impressed with the level of help people are willing to provide. Thank you.

I checked out rock auto and napa, and it looks like that seal is the same seal they used on the NP242 in 1996, which is interesting. I think that's the one I'll pick up though! Now the next step is to find a little c-clip retainer to replace the broken one. I am tempted to just do the SYE, as I have an extra front driveshaft, and it would give me some replacement hard parts, and a good reason to tear into the case. We'll see, but for now, I have a lot more knowledge than I did before. Thanks!
 
I too have a 96 build year XJ. Mine has the yoke that does NOT enter the case.If yours has the slip yoke that fits inside the tail shaft housing get the pre 96 seal and bushing.
 
I too have a 96 build year XJ. Mine has the yoke that does NOT enter the case.If yours has the slip yoke that fits inside the tail shaft housing get the pre 96 seal and bushing.




It sounds like you and I have the exact same model. As it turns out, a lot of the generic parts store listings have the wrong seal. They show the seal for the older version, where the slip yoke does enter the sealed volume.



I ended up finding the correct seal (which as it turns out, is also the part listed for a '96 XJ with the NP242), by looking up a '98 NP231 seal at NAPA. I installed it yesterday and everything seemed fine. I think it leaks worse than before now though! I don't see any damage to the seal, and I was very careful sliding it over the splines. Grr! :mad:
I pulled the rear driveshaft again, put it in 2wd, set the parking brake, and put er in drive to see the shaft spin. It barely leaks at all on level ground or when facing downhill, but as soon as I park it facing uphill, it leaks like a sieve. Maybe the SYE needs to happen sooner than later.... There was not an appreciable amount of radial slop in the output shaft, so I think the bearings are fine. There was some axial play though, the shaft moves in and out a bit. I guess I just assumed that was fine. Any suggestions?
 
My 1996 was built in June of that year. Many of the parts including the NV231 are found on the later year XJ's. The discount store often list the wrong parts for my XJ. The dealer uses the VIN to locate the correct parts.

Don't get started on the wiring and connectors. They are not referred to as the "red headed step child" for nothing
 
My 1996 was built in June of that year. Many of the parts including the NV231 are found on the later year XJ's. The discount store often list the wrong parts for my XJ. The dealer uses the VIN to locate the correct parts.

Don't get started on the wiring and connectors. They are not referred to as the "red headed step child" for nothing
My last Jeep was 6 years ago, a '99 TJ, and man did I think that thing had electrical issues... I can't wait to see what I'm in for now. Haha.

Any advice on rear output shaft end play?

Sent from my SM-A505U1 using Tapatalk
 
Didn't see an answer on that 'extra' piece you found behind the seal, so here's what I heard about that.. I was watching videos on how to change the seal, and one guy had I believe the same piece.. he said it was originally part of the seal and it had broken off.. leading to a bad leak.
 
^^ disregard.. the pic was so big I didn't see the part, but now I do.. Looks more like a broken c-clip?
It is a broken c clip, and I can see the groove it sits in. I found some stuff online that said it was a retainer for the bearing ID. There's a big internal snap ring that locates the bearing race though, so I just left it out for now. There are plans in the near future for a SYE, so I figured I'd try it, as I'm going to replace that bearing by virtue of installing the SYE

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My last Jeep was 6 years ago, a '99 TJ, and man did I think that thing had electrical issues... I can't wait to see what I'm in for now. Haha.

Any advice on rear output shaft end play?

Sent from my SM-A505U1 using Tapatalk

I replaced the tail shaft with a kit that replaced the slip shaft to what known as a "Slip Yoke Eliminator". I needed it now that the XJ sits at 4.5 inches of lift.

My XJ do not have many electrical issues, just that if I need to replace or add anything too compeer the connectors before I take the items offered at the discount parts stores. That includes light bulbs, as simple as it seem. The '96 is a lot more trouble free that the 1994 I once owned.
 
Well, I figured since it was leaking again after the new seal, I'd dive in and see what was up. Unfortunately I couldn't get a good picture, but the seal had a tear along it, circumferentially. When I pulled it out, the spring from the inner lip was off on the shaft. I think possibly the inner c clip that was broken, that I decided to omit for giggles, maintains the shafts axial position, rather than locating the bearing, as I read. With the shaft able to move about, I think it's possible that the spring slipped into the c clip groove and tore the seal. Oh well. I guess it is an important part. Hopefully the SYE I just ordered will take care of it all. And hopefully the front driveshaft I'm getting from the junkyard will fit in the back as well. 🤞

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