Fun with an XJ

Interesting thread. I keep thinking a 2-door, manual trans Cherokee would be a good DD for me. Off to peruse Atlanta Craigslist !

Cool build. I'm a big XJ fan and have owned 4. 

Highway manners on an XJ are HIGHLY variable based on tires. I have had the same XJ feel a little disconcerting at highway speeds on one set of tires and feel completely normal on another set. Luckily they are 5x114.3 so the cheap take-off wheel/tire options are endless. 

As far as the earlier Renix 4.0 XJs, i dislike them. Not because they don't perform well, but because their wiring is highly inferior to the chrysler stuff that came later. So not only do you get 40 more hp with a later jeep, you also get wiring and connectors that don't crumble to pieces when touched. And.. much easier to hook up to and diagnose problems with the Chrysler obd1 system. 

Brakes are a weak spot on an XJ. They are fine for the XJ itself but if you majorly increase wheel/tire weight or add a trailer they are inadequate. 

Make sure and check for slack in the brake hoses and diff vent tubes when suspension is at full droop. 

Anyway, very cool project. I honestly think these things are at their best when only mildly modified. This one seems to be taking an approach i can relate to and be enthusiastic about. 

I really like this build and I'm watching it with interest as I cruise CL for a used WJ/ZJ.  I like the XJ but I want a little more room/comfort.  I'm going to look at one with a similar lift this weekend. 

This thing is rock solid on the highway, even before a post-lift alignment. I did toss a new steering damper on it because they’re cheap and the previous one looked tired. 

I’m not sure a WJ has any more room inside other than the back seat 

Hey Vigo when you said "you get 40 more hp with a later jeep" I'm not sure that is accurate. The stats I looked at show the Renix made only 17hp less than the HO (173hp@4500 rpm vs. 190hp@4750 rpm) not 40hp. In addition the torques for Renix come in at a very low 2500 rpm vs. the HO at 3950 rpm, which is well suited for city driving.

That said we weren't looking for a 1990, the "best years" of the XJ were the 1998/1999 so that's what I had been hunting. The 1990 is was what Keith stumbled upon and was in such excellent shape for the price it would have been hard to pass it up. I really do prefer the chrome bumper/grille of the earlier models, it works to remind me that the XJ is 27 years old. And this one only had three owners, the Midland Corporation for the first 17 years, then a some local buyer for the next 9 (serviced at the same place as before), finally a girl apparently bought it and moved it to Colorado and sold it within a year. This history as compared to the 1998 XJ Keith was actually on that dealer lot to inspect which had 6 owners in 20 years with every warning light lit and the A/C lines had all been sawzalled through.

Sometimes you have to be willing to work with what you find, embrace surreptitious discovery.

I suspect that was meant to be serendipitous, but surreptitious is more fun. 

I wanted the 1990 when I saw it. It has a chiseled character to it that was lost in later, blobbier redesigns. Eric has been flirting with a vintage vehicle for a while, and the look of this XJ is older than the actual age of the vehicle. Since this is a fantasy vehicle as much as a workhorse, having the right vibe was important. Plus, as noted, it was in pretty decent shape. We probably could have bargained harder given the kickdown problem it had at the time, but the truck was already well under the price range we'd been looking at.

There's not going to be any work done on it this week by myself, but I've tossed the keys to a coworker who's going to sort out the AC system and check the rear wheel bearings. I don't have the knowledge or tools to do AC and I don't know what the rear bearings are supposed to feel like on one of these. They did seem loose to me, though.

Keith Tanner said:

I’m not sure a WJ has any more room inside other than the back seat 

True, but that's part of the reason. I want to be able to put a couple mountain bikes and gear inside if possible like I did in the 3rd gen Exploder I had. Pull the front wheels and drop in a board with fork traps. That bit of extra space in the back helps.

Keith Tanner said:

Ha! You’re not wrong there. Eric needs to have DRLs for Canada so it may only be when the Jeep is parked. 

Recon, looks like you could install the “euro” Suburban lights then swap in LED replacement bulbs. I haven’t been able to figure what the dimensions of your current lights are but CarID does show the 9005 conversions. 

you can run a de-powered low beam or high beam as a DRL FYI. that would make it compliant. the new pacifica does this for example. That lower eyebrow light is just signature lighting, its not a DRL because its not bright enough.

fidelity101 said:

Keith Tanner said:

Ha! You’re not wrong there. Eric needs to have DRLs for Canada so it may only be when the Jeep is parked.  

you can run a de-powered low beam or high beam as a DRL FYI. that would make it compliant. the new pacifica does this for example. That lower eyebrow light is just signature lighting, its not a DRL because its not bright enough.

Exactly. Which means you'd only see the headlights off when Jeep was parked. That was my original statement. I'll check to see if the connectors are there, and hopefully it'll be possible to plug in the Canadian-spec DRL module which runs the headlights at 50%. The problem with that is that it's easy to forget you don't actually have your headlights on at night and thus have no taillights, so running the full head/tail combo switched with the ignition is a little more idiot-proof.

ultraclyde said:

Keith Tanner said:

I’m not sure a WJ has any more room inside other than the back seat 

True, but that's part of the reason. I want to be able to put a couple mountain bikes and gear inside if possible like I did in the 3rd gen Exploder I had. Pull the front wheels and drop in a board with fork traps. That bit of extra space in the back helps.

 

I can try that on both if you'd like. The load area floor is much higher on a WJ because the spare is under the floor, while the roof is at about the same altitude. You're planning on having the bikes upright?

Hey Vigo when you said "you get 40 more hp with a later jeep" I'm not sure that is accurate. The stats I looked at show the Renix made only 17hp less than the HO (173hp@4500 rpm vs. 190hp@4750 rpm) not 40hp. In addition the torques for Renix come in at a very low 2500 rpm vs. the HO at 3950 rpm, which is well suited for city driving.

You're probably right. I was going strictly off of memory and thinking the Renix were rated around 150hp. I do think the power difference at high rpm is noticeable (i owned both) although not high on anyone's list of factors either way! As far as the torque goes, I would have to see a dyno chart to believe that the HO was making noticeably less torque than the Renix at any point. If the Renix makes (for example, as i dont remember) 240tq at 2500 rpm and 190tq at 3950rpm while an HO makes 230tq at 2500 and 245tq at 3950, the HO would be overall superior for having a wider plateau of torque. Anyway, discussions of handfuls of tq or hp are near-pointless and im not trying to pick nits. Any 4.0 XJ is a torquey and pleasant drivetrain for a very truck-y old truck and if we're going to turn our noses up at any XJ engines we can probably agree to single out the old 2.8 GM v6 instead!  

In reply to Keith Tanner :

Hey, that would be great. Yeah, bikes upright, front wheels removed and on a fork trap at the rear gate so the bike faces backwards. I did have to remove the seatpost and saddle on the bike for the Explorer come to think of it.  My new dual sus has a dropper post on it, so that might be necessary anymore. Actually, measurements of interior height and fore-aft length with the rear seat folded would be just as helpful if that's easier.

The other issue I've had in XJs is that the seats and ergonomics just aren't that comfortable. Of course, my experience is with late 80's models and clapped out later models, so maybe it's not representative. I'm hoping the comfort level in the WJ would be higher.

If I test drive a couple and don't like them my fall-back is a full size SUV, probably 2wd, probably an Expedition since I'm Ford biased, but that's a topic for another thread.

I'll do those measurements next week - the XJ is currently in the hands of a coworker.

The WJ has blobby seats with no lower back support, but you can get further away from the steering wheel than you can in the XJ.

In reply to Keith Tanner :

That may be perfect. I find most newer vehicles' lumbar supports to be obnoxious.  The seats in the 96 F250 are some of the most comfortable I've ever done long miles in, and that's with the lumbar deflated and 245k miles on them.

BTW I'm not picking nits or a fight, I'm just a little bit of what the Brits would call an "anorack" in just about any topic that gets in front of me. Good for work, can be disruptive socially. Anyhow here is a pic comparing the HP/Torques from Left to Right of L-Renix M-Chrysler Gen 1 and R-Gen 2 HO engines

As you can see the Gen 1 was a major step down compared the Renix for torque, but the HO makes it back up to be better than the Renix in most respects. But of as Vigo said this is splitting hairs compared the 2.5L 4cyl. 

The thing that got me interested was the NP242 transfer case with the four-wheel-drive high that gives a constant 48/52 differential torque-biased-drive. This is perfect for winter driving in this city with a mix of unplowed side streets and over-salted main streets where you need to be constantly shifting 2WD Hi/Lo.

Hey unltracycle if you want a super-convenient way to move two bikes upright inside a vehicle you should at least consider the Honda Element. It does things like

In reply to Ottawa :

True, but it sucks for towing a boat 3 and a half hours to the coast and exploring forest service roads! Honestly, the average mini van would probably be a better solution for my real world needs but it's not like I'm willing to drive one.

Well, umm, not if that boat was more like a wind surfer, but OK point taken. Can't see how I didn't process the Ford Expedition comment.

You might want to consider the RWD Tahoe similar to PPV (Police Pursuit Vehicle) spec. Its a RWD SUV with what seems to be the highest duty cycle of any current Gov't vehicle based on the mileage at resale.

In reply to ultraclyde :

Just FYI, I can do that in my Xterra no problem. Something to consider. I put 2 in the back all of the time mounted into a 2X4 with fork clamps on. 

I appreciate the help guys, but I don't want to steal Keith and Ottawa's thread. I will go start another thread with regard to my SUV hunting. Thanks though!

Back at it!

The HVAC system was stuck on defrost. You could choose hot defrost or ambient defrost (no AC...yet) but the zone selector it does nothing. While I was out of town, I tasked my coworker Matt with hunting this down as well as fixing the AC and checking the rear wheel bearings. The bearings were given a bad report card so we'll get to those. The blend door was tracked down to a broken vacuum line, so that was an easy fix.

Is this non-GRM to ask someone else to handle things? Maybe. Matt's always looking for ways to pick up work and I don't know anything about how wheel bearings should feel in a c-clip axle or how to do AC stuff. So everybody wins.

Back in my garage, I swapped in the new, longer rear shocks.

Much better. I also had been hearing a rattle that sounded like a loose sway bar end link, and so I checked things out while changing the shocks. Once I'd tightened up the loose sway bar end link that I found, the noise went away. The truck seems much happier, I could feel the shocks topping out before. Interestingly, the dust on the shock shaft for the shorter one indicated that I hadn't been using the last 1" of shock travel, so I'm not liable to miss it at all.

I also installed a modern necessity. The XJ predates the invention of the cupholder. Luckily, the aftermarket has a $13 solution.

I pulled the driver's door apart to see if I could get the door lock actuator to work - it's trying but not able to lock/unlock. Lubrication didn't help, so it may be time for a new part. And did a few other little fiddly things, including learning that it's not possible to pull an XJ steering without a steering wheel puller no matter how hard you wiggle. The wheel.

I had a bit of a rough week, under attack by a squadron of shiny happy people. The best way to forget them is to dive into something noisy and creative and involved. So it's time to mount the push bar.

I wanted to to be functional, so simply attaching it to the bumper wasn't going to work. That just bends the bumper. I pulled the bumper off and had a look behind. The width of the bar wasn't quite enough to hook up to the stock bumper mounts. So I decided that I didn't need a bolt on solution and I had a welder. This is going to be one solidly mounted push bar.

Step 1, clean off the front of the frame rails. That's the bumper mounting flange just to the right, attached to one side of the frame rail. The oval hole is the end of the rail, with the other side of the box at the edge of the oval.

The plan was to weld a plate on to the front with a couple of 1" square tubes protruding with 2" between them. That's sized to fit nicely through the bumper. I put a 2x1 tube between the two of them to sit right over top of the end of the rail to transfer all force straight to the frame rail and keep things from flopping around. Coincidentally, it also happened to be what I had sitting around.

Welded in.

But I had a doofus attack. I was going to put the tubes inside the push bar uprights, 25.5" apart. I spaced them appropriately and welded everything in. Then I held up the bar to the new mounts and found out that I'd put 25.5" between the inside of the mounts, not the outside. So the inside of the uprights was lined up with the inside of the mounts, and that only works if the push bar uprights were of zero thickness...which they are not.

Nuts. 

But I'd been thinking of another mounting setup that used 1/4 x 1" strap through the bumper. It was time to put that into play. I chopped the 1" tubes down so they'd sit behind the bumper instead of poking through, and welded 1" strap to the lower one and 1.5" strap to the upper (which is what I had) instead.

Now, slots in the bumper for the mounts to stick through. Chrome plated steel is hard to cut! Ideally, it was just drilling two holes and connecting them using the grinder. I think that only worked well once, so I casually took a picture to make it look like that's how they all worked.

And voila. Some very burly mounts sticking through the bumper, designed to transfer any impacts straight into the frame rail. It would probably work for pulling, too.

And we're done. Of course, I needed to go for a quick test drive although I didn't push anything. I left the front plate mount in place because Eric will need it, but I did lose the dealer plate.

Cherokee bumpers are flimsy, but chalk it up to the compromises involved in having a quite capable 4wd 5-seat solid-axle SUV that weighs only ~30% more than a Miata. It's almost crazy when you think about it. 

All bumpers are flimsy, really. They're designed to fail gracefully while absorbing impact and protecting other things. Push bars are intended to stand fast and inflict damage on whatever's on the other end. I was lucky in that I'd had a chance to check out the Go Rhino "factory" mounts for my Dodge when I installed that push bar. That is not a vehicle that weighs only 30% more than a Miata, and they don't attach to the bumper either 

Here in Texas big trucks with aftermarket 'full replacement bumpers' are very popular. They typically weigh a ton (i've helped paint and install some) and are extremely strong. As you say, the purpose of stock bumpers is to soak energy by crumpling. One of the things i dont think 99% of people buying those bumpers understands is that they are so much stronger than stock that when you wreck the truck the bumper just transfers energy straight through to your framerails and makes it much more likely that the truck totals out (and much less than 100% of 'mod money' spent is recouped). They essentially make the vehicle more dangerous to the owner, other drivers, and pocketbooks. But they look cool! But, with vehicles as old as this Cherokee making frame damage more likely is really a moot point since anything of this age/value essentially totals out instantly in any kind of real incident. I'd say those things make MORE sense on a 3k truck than a 30k or 60k truck. 

I like the understated but functional look of the push bar. Id like something to make the front of the ZJ I have a little more appealing, but I'm not going rock crawling. Something like this would make sense if I can find one that's cheap and decent.