how do ID which transfer case I have?

'01 XJ Sport, Auto. Looks like my noise issues were from the t-case, not the front diff as first thought. AAMCO wants $1500 for a reman unit. Lots of choices out there for $200-300 used on ebay and it looks like swapping it in is 1.8 hours by the book.

Crawl under the jeep and look at the round tag on the back of the t-case. You should have a NP 231

You have a 23-spline input.

If you have "2WD-4HI-N-4LO" you have the NP231.

If you have "2WD-4FT-4PT-N-4LO" you have the NP242.

The jury is out on which one is "better" - I believe the NP242 has the stronger input gearset (six planets, vice three, in most cases,) but upgradability is better for the NP231. That said, I'm still planning on putting a 242 in behind my AX-15 when I can - I want the "full-time" option. Every advantage I can get in dealing with these idiots out here won't be enough, but it's better than not having options...

(Now, if I can just track down selectable AWD. Still need to get a pair of D44s set up - damn City got difficult about my keeping the two I had around. Small-minded pismires...)

no full time for me. worth upgrading to? any good walkthroughs on it?

PGT FTW said:

no full time for me. worth upgrading to? any good walkthroughs on it?

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Meh - it all depends. As I said earlier, I simply want an extra option for dealing with these people (PT4WD is a 52/48 front-biased split, while FT4WD is a 50/50 differentiated torque split between ends. Not quite AWD, but close.)

Upgrading is fairly simple - swap transfer case and shifter (easier if you have an auto - I don't think the NP242 was ever put behind the AX-15 or NV3550 by the factory. Doesn't stop some of us from doing it afterward, tho...)

Advantage to FT4WD mode? You can use it on pavement for extended periods without grenading your case. If you try that with the NP231 for any length of time, you're doing good if you only stretch the chain (pictures of grenaded cases have been posted here - it's pretty ugly.)

If you plan on spending significant time off-road, consider sticking with the NP231. SYE kits are easier (making it a "fixed-yoke" output,) and low gear kits are easier. Or, you could stick in an Atlas or one of the reissued Dana 300 cases (gear driven, selectable shift. No FT mode, IIRC. But, you can shift into high/low range, and into RWD/4WD/FWD at will.)

It really depends on what you plan to use your vehicle for - so if you get the itch to think that the NP242 would be a viable upgrade, sit down and chew on it for a bit, and feel free to solicit opinions (take with a suitable grain of salt - most people are probably going to tell you the NP231 would be better for your needs. Then again, most people have trouble breaking out of their moulds as well - everyone's needs are, ultimately, different. You wouldn't build up your rig the way I plan to do mine - fortunately, I don't expect you to.)

we did tons of offroading in the old TJ. This XJ is for hauling the baby, the dogs and mulch as well as snow duty in the winter when my MINI doesn't leave the garage. 50/50 and FT makes sense there but honestly, 4Hi isn't needed much around here (based on my TJ experience) as tires make the most difference.

PGT FTW said:

we did tons of offroading in the old TJ. This XJ is for hauling the baby, the dogs and mulch as well as snow duty in the winter when my MINI doesn't leave the garage. 50/50 and FT makes sense there but honestly, 4Hi isn't needed much around here (based on my TJ experience) as tires make the most difference.

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Sounds about right - then stick to the NP231 for the easiest replacement

Your noise may be from a stretched chain - should be a fairly easy swap. You can probably get an overhaul kit for a couple hundred, do it yourself in the garage in a week-end (or less!) and come out ahead - both in terms of money and in terms of work done (an overhaul kit will have bearings and the like as well - may as well replace them while you're in there, you know? The shop sure as Hell won't, if they crack the case themselves. They should be done on a reman; but that $1500 is just for the case, yes? I'd find it unlikely that that pricetag includes the R&I; and if it does, that doesn't say much about the quality of the reman unit to me...)

what harm is there in swapping in a used one for $300? From what the tech at the shop said, it can be as quick as 15-30 minutes as much as a couple hours.

PGT FTW said:

what harm is there in swapping in a used one for $300? From what the tech at the shop said, it can be as quick as 15-30 minutes as much as a couple hours.

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Not much - just make sure it's got the 23-spline input (1990-up XJ, most Dakota, ... It's easier to find than the early 21-spline!)

If you're going to get a used one, pull it at the boneyard yourself (should take about an hour - you'll want to have a 9/16" "stubby" wrench to get the upper nuts) and split the case. If the chain looks good (I think it's a spec of 1/2" of deflection from a striaght line, but don't hold me to it at hte moment,) seal it back up and toss it in. Rebuild the old one for later - it's a quirk of chain-driven cases that you'll need to replace it again.

A boneyard pull may have plenty of good life in it - but I always like to make sure, and if alles gut, you're only out a couple of hours and a tube of RTV (and you've learned how the thing goes together in the process, so it's not time wasted.) If the chain is shot, you've already got it torn to bits, you can rebuild it on the bench, and your DD is still in service.

Check your local stealership i bought a bran-new one for only 900 bucks.

PGT FTW said:

what harm is there in swapping in a used one for $300? From what the tech at the shop said, it can be as quick as 15-30 minutes as much as a couple hours.

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None. Do you have a pull-n-save type salvage yard near you? They usually charge $50-60 for a xfer case. As mentioned, they are pretty easy to pull.

thanks all....I picked one up on ebay with 77k miles from LKQ (salvage place). $120+ shipping.

Next Q...any good walkthroughs for the R&R? Or, just unbolt and remove and put the new one in?

PGT FTW said:

thanks all....I picked one up on ebay with 77k miles from LKQ (salvage place). $120+ shipping.

Next Q...any good walkthroughs for the R&R? Or, just unbolt and remove and put the new one in?

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Two things that I can think of:

1) Note the orientation of the shift linkage for the thing. I always get it upside down...

2) Have a "stubby" wrench for the upper nuts, it's a lot easier. Should be a 9/16" size that you need. You won't be able to get a socket on it easily...

I have a set of stubby gearwrench