zak Posted January 19, 2016 Share Posted January 19, 2016 I’ve owned a 92 MJ 4.0 4x4 AX15 for almost 10 years now. Runs great, never had any major problems with it, daily driver. 5 weeks ago I picked up a 96 ZJ for a great price, that was in AMAZING condition. Last weekend someone pulled out in front of me and my wife and the ZJ was totaled. (Thankfully no one was hurt, except for the Jeep, but held up pretty damn good considering) So my question is, what’s worth keeping and swapping to the MJ? The ZJ has a 4.0 with I believe the 242 transmission? I know I want to keep the 4.0 and possibly do some engine mods for a future swap into the MJ. From what I can tell when I looked at it I don’t think there is any engine damage. The radiator got a nice hole blown in it somewhere, but wasn’t pushed in far enough to hit the fan or anything else. The transmission had a slight slip when I bought it, would slip going into 2nd and 3rd for the first time every time I drove it, once it finally grabbed it would be fine for the rest of the trip. I’ll probably pull it and set it aside for now but really don’t have any future plans for that or the transfer case. Don’t know if it would be worth it to get it worked on and sell it, or just sell it 'as is' for cheap hoping someone with the knowledge can fix it up. As for the axles, I haven’t confirmed any of this but I believe the MJ has 3.08 or 3.10 gears, would anyone here be able to confirm this? Mine doesn't have the tow package and I know the rear is a D35 and the front a D30, I’m guessing that’s pretty standard, and the ZJ has 3.55s from what I’ve read online from what was stock for that year (it’s a laredo). Main question here is would it be easier to swap out the whole axles, or swap out just the guts, everything should be interchangeable since they’re the same axles correct? Or would this be worth doing at all? I never plan to go off roading with it, but maybe down the road put a small lift on it with a somewhat bigger tires. (The whole point of me getting the ZJ was to have a new daily driver so I could slowly start working on the Comanche as I had the money, needs a little body work, nothing major, desperate need of some new paint) I also like the idea of converting the rear brakes over to disc, but again not sure if it would be easier to do a whole axel swap or just remount everything? I think that’s all my questions... for now anyway. If anyone is looking for ZJ interior parts I’ll probably have them up on craigslist if anyone is in the Hampton Roads area of VA. Would hate to see them go to waste but I have no use for them now, the interior was in EXCELLENT condition minus carpet stains, but the seats have no rips, tears, stains. and the dash didn’t even have any cracks in it until the airbags came flying thru it. Thanks in advance! Link to comment Share on other sites More sharing options...
gogmorgo Posted January 20, 2016 Share Posted January 20, 2016 The ZJ rear axle will need perches welded on to work under the MJ. That's still going to be easier and/or cheaper to pay someone else than it would be to set up the ZJ's gears in the MJ's axle. Front should bolt in. I want to say it'll be low pinion, but that shouldn't be a huge problem unless you want to do serious off-roading, which doesn't seem to be the case. Your MJ will have 3.07 gearing. The 3.55's will be a noticeable upgrade. Engine should physically bolt in, although you'll probably need to reuse a bunch of the MJ's accessories. Also '96 was a bastard year between OBD1 and OBD2 in the XJ, don't know about the ZJ, but there might be sensor weirdness there. The trans won't be the AW4. By most accounts the ZJ trans isn't worth fixing. I don't think the 242 will bolt onto your ax15 (but I could be wrong). I've also heard but can't confirm it's got a viscous coupling instead of the XJ 242's differential which makes it less desirable, but otherwise my 242 was an excellent upgrade from the 231 in my '91. In my mind it actually makes the 4x4 useful in winter in more than just deep snow. The steering gearbox has a much quicker ratio and if it's still in good shape will make an excellent upgrade. The front away bar, again if it's in good shape, will also tighten up the handling. You can probably rob stereo parts and lightbulbs and stuff... Running out of things to think of. Wheels and tires? People use ZJ springs for lift? Link to comment Share on other sites More sharing options...
FrankTheDog Posted January 20, 2016 Share Posted January 20, 2016 The ZJ 242 doesn't have a viscous coupling in it. The ZJ 249 has it. It's in the quadratrac which is just 4 hi and 4 low. The 242 is nice in slippery conditions. It may not match up to the ax15 or aw4 because it has a slightly shorter input spline. A spacer may allow it to match up. Link to comment Share on other sites More sharing options...
gogmorgo Posted January 20, 2016 Share Posted January 20, 2016 Mm. Right. Forgot about the 249. ZJ tie rod should be a bit beefier too. Link to comment Share on other sites More sharing options...
zak Posted January 20, 2016 Author Share Posted January 20, 2016 The ZJ rear axle will need perches welded on to work under the MJ. That's still going to be easier and/or cheaper to pay someone else than it would be to set up the ZJ's gears in the MJ's axle. Front should bolt in. I want to say it'll be low pinion, but that shouldn't be a huge problem unless you want to do serious off-roading, which doesn't seem to be the case. Your MJ will have 3.07 gearing. The 3.55's will be a noticeable upgrade. Engine should physically bolt in, although you'll probably need to reuse a bunch of the MJ's accessories. Also '96 was a bastard year between OBD1 and OBD2 in the XJ, don't know about the ZJ, but there might be sensor weirdness there. The trans won't be the AW4. By most accounts the ZJ trans isn't worth fixing. I don't think the 242 will bolt onto your ax15 (but I could be wrong). I've also heard but can't confirm it's got a viscous coupling instead of the XJ 242's differential which makes it less desirable, but otherwise my 242 was an excellent upgrade from the 231 in my '91. In my mind it actually makes the 4x4 useful in winter in more than just deep snow. The steering gearbox has a much quicker ratio and if it's still in good shape will make an excellent upgrade. The front away bar, again if it's in good shape, will also tighten up the handling. You can probably rob stereo parts and lightbulbs and stuff... Running out of things to think of. Wheels and tires? People use ZJ springs for lift? Awesome, thanks for the info. I have access to a shop with a lift, and a buddy who used to work at an off road shop and has his own welder, so I'm thinking I'll get him to help me switch the rear if I take that route. I'm sure there's a how to I can find somewhere to help the process. Figured the transmission wasn't really worth the trouble, I'll have to do some more digging on the t case As far as the front end, I replaced 80% of the MJ a few years back, tie rod ends, control arms, ball joints, wheel hubs, so knowing about the steering box is good, that's one thing I considered but skipped over due to money. And I think the sway bar was damaged in the ZJ, haven't gotten it back from insurance yet but it looked like the front skid plate was pushed into it a good amount. Wheels and tires are deff getting pulled off. I mentioned the interior being in great shape if anyone was interested but guess I didn't mention the exterior that's still good. The whole front is smashed in along with hood and passenger fender. From what I could tell the driver fender wasn't touched and the rest of the body is rust and dent free, so doors, tailgate all that is in perfect condition. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 20, 2016 Share Posted January 20, 2016 Rear discs and prop valve guts. Seats. Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 20, 2016 Share Posted January 20, 2016 The quick ratio steering gear didn't get fitted to the ZJ's until mid-1993 and lasted through 1998, so an early 93 may or may not be a 12.7:1 box. If the ZJ build date plate indicates a date past manufacturing mid-year 1993 it should be correct, or the steering gear itself may still have the correct alpha code tag attached indicating a 12.7 box. These codes were: ALBTJHKDWK Link to comment Share on other sites More sharing options...
Rockfrog Posted January 20, 2016 Share Posted January 20, 2016 Huh? The ZJ entered production for the 93 model year ... Making a mid 92 build date the first build date. Essentially meaning all ZJ would have the quick ratio box ... No? Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 20, 2016 Share Posted January 20, 2016 The ZJ was first introduced in April 1992 as an early 1993 model year vehicle. These early ZJs had the same steering gear as the XJs with the 14:1 ratio. This is according to Jim Shea, a retired Saginaw engineer. All I'm saying is ID the early "92" produced ZJ boxes to make sure they have the quicker ratio if it comes from an early 93 ZJ. But you are right, they were all called 93's so I'll edit my original post. Link to comment Share on other sites More sharing options...
gogmorgo Posted January 21, 2016 Share Posted January 21, 2016 OP's ZJ is a '96. Good info, though. Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 21, 2016 Share Posted January 21, 2016 I quickly read "92" in the original post, but that was for the XJ, not the ZJ. Triple :doh: . So, yes, your 96 ZJ steering gear is the quick ratio box. Link to comment Share on other sites More sharing options...
zak Posted January 21, 2016 Author Share Posted January 21, 2016 I quickly read "92" in the original post, but that was for the XJ, not the ZJ. Triple :doh: . So, yes, your 96 ZJ steering gear is the quick ratio box. All good! Haha, still good info to know. So as log as its in good shape it should be worth switching into my Comanche. Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 21, 2016 Share Posted January 21, 2016 Very worthy, it's a great upgrade. These boxes are sought after by the 70's-80's GM muscle car guys too. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 21, 2016 Share Posted January 21, 2016 I've got two 93 ZJs I'm gonna part out. How can I be certain whether they do or do not have the quick ratio boxes? Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 21, 2016 Share Posted January 21, 2016 Read my post above and look for the alpha code on the box, and the ZJ build date. If the alpha code is gone from the box, do a stop-to-stop arc bench test with a protractor. 1992 1/2 - 1998 JEEP GRAND CHEROKEE FAST RATIO POWER STEERING GEARSYEAR ALPHA CODE ORIGINAL APPLICATION GEAR RATIO EFFORT T-BAR SIZE TRAVEL1992.5 -1993 AL or BT Jeep Grand Cherokee 12.7:1 20-26 0.195 Dia 43deg 45min1993 MN Jeep Grand Cherokee 12.7:1 20-26 0.195 Dia 43deg 45min1994 AL,BT,PD,ZJ Jeep Grand Cherokee 12.7:1 20-26 0.195 Dia 43deg 45min1995 JH Jeep Grand Cherokee 12.7:1 20-26 0.195 Dia 43deg 45min1996 KD Jeep Grand Cherokee 12.7:1 20-26 0.195 Dia 43deg 45min1997-98 WK or BT Jeep Grand Cherokee 12.7:1 20-26 0.195 Dia 43deg 45min Link to comment Share on other sites More sharing options...
cruiser54 Posted January 21, 2016 Share Posted January 21, 2016 1-93 and 3-93 production dates. No letters visible. Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 21, 2016 Share Posted January 21, 2016 If they are off the vehicle stick it in a vice and count the rotations stop-to-stop while turning the output shaft. If it's 2-1/2 to almost 3, it 99% certain it's the 12.7:1 box. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 22, 2016 Share Posted January 22, 2016 Just jacked up the 3-93 ZJ and turned the steering wheel. About 2.75 turns lock to lock versus 4 turns lock to lock on my 87 MJ. I'll check the 1-93 later. Link to comment Share on other sites More sharing options...
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