curious.......

What are the most significant differences in the diff. XJ years? I know the doors/tailgate bolt up differently. There are differences in the electrical crap/engine/tranny and cosmetical junk. But are the bodies basically the same? Meaning, could you strip down lets say a 91' down to it's core unibody (no engine/tranny, insides, doors, dash, fenders ect ect) and swap in lets say a 99' everything? (don't ask why, it's purely hypothetical, but for a reason). I know some modifications would have to be made to make the doors and crap work.
Reason for asking is that I like parts of old and new. I might have a chance to grab some "newer" style parts cheap (an entire dash assembly and wireing). I'm wondering if I could swap it in.

Using your 99/91 example,the e-brake on the 99 is routed along the driver's framerail instead of the centered one like the earlier XJs.

Not counting the differences in the third light, you'll find that the 94-86 engine bay and hood pull are different since the V6 and I4 were used that year. In 87 the engine bay was lengthened and the hood latch changed.

Bodywise there weren't many other changes I can think of until 97 except the seat mounts changing in (95?) and the changeover to the Chrysler column around that time as well.

Material for one of my next books - the XJ Parts Interchange Guide.

Here are the generations:
1984-1986 - First generation. Came with Renault 2.1L I4 Turbo Diesel (rare!) AMC 2.46L I4, or GM 2.8L V6. Shorter front clip than later XJs.

1987-1990 - Second Generation. Overlapped purchase of AMC/Jeep by Chrysler in 1988. Available with Renault 2.1L I4 Turbo Diesel, AMC 2.46L I4, or 4.0L I6. Front clip/nose lengthened to accommodate I6 block.

1991-1995 - Third Generation. Featured 2.46L AMC I4 or 4.0L I6, both with Chrysler OBD-I Electronics. Same sheetmetal, but ChryCo steering column. I'm not sure if the IP swaps directly or not.

1996 - "Interim" year - began OBD-II electronics, added main bearing girdle to engine. Same sheetmetal as 1987-1995 model years.

1997-1998? - Fourth Generation. OBD-II electronics, Main Bearing girdle. Changes to sheetmetal and interior by ChryCo.

1999?-2001 - Fifth Generation. Same sheetmetal as 1997-1998, but changed to coil-on-plug distributorless ignition system. Intake manifold changed to feature greater plenum volume and curved runners.

I'd have to dig out my notes to give you more details on engine changes, but that's the biggest parts. I'm also willing to entertain specific questions, if you're not in a hurry... :laugh3:

5-90

5-90 said:

Material for one of my next books - the XJ Parts Interchange Guide.

Here are the generations:
1984-1986 - First generation. Came with Renault 2.1L I4 Turbo Diesel (rare!) AMC 2.46L I4, or GM 2.8L V6. Shorter front clip than later XJs.

1987-1990 - Second Generation. Overlapped purchase of AMC/Jeep by Chrysler in 1988. Available with Renault 2.1L I4 Turbo Diesel, AMC 2.46L I4, or 4.0L I6. Front clip/nose lengthened to accommodate I6 block.

1991-1995 - Third Generation. Featured 2.46L AMC I4 or 4.0L I6, both with Chrysler OBD-I Electronics. Same sheetmetal, but ChryCo steering column. I'm not sure if the IP swaps directly or not.

1996 - "Interim" year - began OBD-II electronics, added main bearing girdle to engine. Same sheetmetal as 1987-1995 model years.

1997-1998? - Fourth Generation. OBD-II electronics, Main Bearing girdle. Changes to sheetmetal and interior by ChryCo.

1999?-2001 - Fifth Generation. Same sheetmetal as 1997-1998, but changed to coil-on-plug distributorless ignition system. Intake manifold changed to feature greater plenum volume and curved runners.

I'd have to dig out my notes to give you more details on engine changes, but that's the biggest parts. I'm also willing to entertain specific questions, if you're not in a hurry... :laugh3:

5-90

Click to expand...

Yeah, i've noted most of these changes. My root question is, is there a difference in the basic unibody. Are most of the mounting holes in the same spots?
I guess this may answer my question......

I think they're basically the same within ranges - 1984-1996 (except for the fenders between 1984-1986 and 1987-1996) and 1997-2001. The blocks are the same all the way up - the changes are in the head (there were four casting numbers) and intakes (there were three,) and the only real change in the block was the machining of the knock sensor boss for 1987-1990 RENIX.

Unibody mounts seem to have changed slightly from 1984-1996 and 1997-2001 (per most bumper makers and such) but I'm inclined to wonder if this isn't something that can't be accounted for with dual mounting bolt patterns on add-on goodies.

Naturally, the marker lights and taillights won't interchange to either side of the 1996-1997 break, but I see no reason why most bolt-ons (apart from the liftgate) can't be adapted. Again, this is something I'm likely to be looking into over the next year or so, time and supplies permitting.

5-90

5-90 said:

Here are the generations:

1999?-2001 - Fifth Generation. Same sheetmetal as 1997-1998, but changed to coil-on-plug distributorless ignition system. Intake manifold changed to feature greater plenum volume and curved runners.

Click to expand...

Two minor corrections to this:

- 1997-up went to the steel tailgate. Unibody stiffness was also significantly improved from this point.

- Only 2000 and 2001 got distributorless ignition on the XJ. 6-cylinder WJs got it in 1999, but no idea if it's compatible with the XJ ECU.

Also, transfer cases changed to the NP231/NP242 from '87-on. Can't remember the model numbers for the early ones, but I'm sure someone will fill that in...

5-90, here's something to work on for you...

Making a Renix use distributorless ignition.

Actually, I'm already working on an idea along those lines... Shan't say anything more - I don't want to uncover my SunkWorks (nod to Lockheed...)

5-90

Aight, well that has pretty much answered what I wanted. An 5-90, when you decide to experiment with parts interchange (actually doing it, not just hypothetical) let me know. Every now and then I come across random parts/years dirt cheap and wouldn't mind helping supply some materials.

You know, it's probably going to be a bit before it gets beyond theoretical - I've got some restomods I've got to sort out, and I'd like to stomp up a "run stand" or two so I can get a couple engines going with easy access to change goodies.

Given the cost of parts around here, and the scarcity of XJs (I don't bother going to PnP yards anymore - and the one salvage outfit that consistently carried XJ stuff folded up its tents and went elsewhere...) I'll have to keep your offer in mind. I'm half tempted to open up my own salvage outfit when I get out of here and get some property, just to make for a source of parts for me, and make it easier for others to find parts as well.

Anytime I've found a Jeep in a PnP yard around here, it was usually a stripped and bleeding hulk. Thanks, but I don't need that many unibodies...

5-90

5-90, I think you need to keep a list, perhaps on your website, of parts that you need for experiments and such. I'm sure lots of people on this board would be willing to keep an eye out for you, considering all the help you provide here. Just a thought.

Hmm. It seems I might have a notebook somewhere with a list, perhaps a list of items suitable for donation may be in order in the future.

Granted, I'm not exactly in a position to start seriously experimenting now, but I will be in a couple more years or so (once I get most of the way through school, WiP gets a little more established, and we unass CA and get some working space!) but there's not much reason I can't start collecting now, once I get organised in the shop so I can keep everything straight...

I'll have to chew on that! I'd honestly not thought of it myself, I tend to think of myself more as a teacher anyhow. Once I get my shop opened up and running, I'll probably pick students at the local high school for apprenticeships, for example. That's just what I've been doing for a number of years on a more informal basis anyhow...

5-90

One other thing I've noticed is that around 97 they changed not only the location of the handbrake handle, but the routing of the cables. This is a great improvement, but it also means you'd need to do a good bit of modification to fit one type to the other, because it involves actual changes to the unibody.

I'm not sure, but I have a feeling also that the shape of various things such as the heater unit changed in 97, so that a dash transplant would need quite a lot of other stuff transplanted as well.

The tailshaft of the transfer case changed sometime in 96 I think, and so did the belt routing in the engine. Driveshaft lengths are all over the map, it seems.

I think also that there is enough difference in the floors that changing seats between 84-94 and 95-up would be a problem.

Steering columns changed a couple of times. 95 gets a redesigned (Chrysler, I think) column with a mechanical airbag. At some point, not sure when but 97 I think, a different column with an electrically triggered airbag replaces that. In addition to different column designs, the controls are differently placed. The 95 steering column uses the same steering shaft as the earlier Saginaws, but the later ones use a different shaft. All the steering gears interchange, but they are not alike internally.

Don't forget that the gauges changed in 91, with electronic speedo and reversed polarity on the sensors, and again in 97 with electronic odometer.

Sometime around 91 the steering knuckles changed to a one piece design. Earlier ones had a separable brake hanger. Also a change from cast to composite rotors and a change in the wheel hub. So although you can mix and match whole axles, you cannot mix and match brakes and hubs.

I notice that the door latches on the 99 are different from the 95 and earlier ones. They use a U-shaped strike instead of a post. I could see that this might cause problems, though I haven't investigated to see if you could put a pre-97 latch into a 97-up door. I kind of doubt it.

if you have the space 5-90, i have the duct work from a 90 id be willing to ship you for free (as a specimin or something). If you say yes, maybe we can go 50/50 on shipping charges. I don't need it, and i will have a bunch of other stock 90 parts coming soon that you can have for a "comparison collection" if you want.