The Cherokee has been an ongoing project that has taken a bit of a back seat to motorcycles in the past few years. With time, space, and money being major concerns while at UC Berkeley, dirtbiking seemed a more practical avenue to the off-road world. Most of the recent work on it has been limited to maintenance and numerous repairs.
Upgrades and Maintenance are broken up into sections with details about each.
Jump To: Maintenance
Upgrades/Mods
Stereo Lighting Battery HVAC mod CB Radio Radar Detector Safety Equipment Hard Parts
Brakes Exhaust Suspension
Stereo
Most of the early work I did on the Jeep was electrical. Since it came with an AM/FM-cassette, the stereo was the first order of business. Chryslers and GM’s come with their own size of head unit, which isn’t single or double DIN. I was looking for an AM/FM-CD-cassette head unit that fit the Chrysler opening. The only one available was the Jensen CM-715k.
I paid almost $400 for it. Jensen came out with a model soon after I got mine that had full logic cassette controls and a subwoofer output. The head unit looks decent except for the ungainly cassette FF/REW buttons sticking out of it. The face flips down to access the CD and cassette.
My major gripes with the Jensen are its cassette control buttons, the main control design, and its CD player.
The main control is a 4-way button that does volume, settings, track, seek, and channel depending on the mode. It sits on top of four surface mount momentary buttons, with a cross-shaped injection molded spring/spacer…which broke. In my opinion it was way too much bending for such a thin piece. Jensen wouldn’t send me a part, and wanted too much for repair or for a new face. I made a flat plastic piece to replace the broken one. It doesn’t serve as a spring like the old one, so the control gets jammed up sometimes, but it’s good enough.
For such an expensive unit, the CD player is pretty weak. It won’t play a lot of CD-R’s, can’t handle any kind of scratches or smudges, and won’t hold its position when it gets turned off.
Along with the Jensen, came four new speakers. I installed a set of Ultimate 3-way speakers in my dad’s old Acura Legend, and hoped I could find them, but they were discontinued, and I could only get 2-ways. They’re alright, I’ve heard better and worse.
Eventually, too much driving and time on my hands convinced me that the Jensen’s internal amp wasn’t powerful enough and that I needed a subwoofer. Not looking to spend a whole lot of money, I found some cheap no-name stuff. I wasn’t looking to win any competitions or to be the fool who plays his stereo loud enough for the rest of the world to hear. A RadioShack subwoofer crossover was necessary to keep the high-end out of the sub. The two amps and crossover fit nicely under the back seat on the driver’s side. I put the amps on an aluminum plate so I could wire them and put the entire unit in.
The crossover was an afterthought, so it’s separate. I had some pretty major alternator whine in the stereo after all of this equipment was installed.
I made sure to separate the power wire for the amp from the signal wires, but it didn’t help. I got a signal filter at Fry’s Electronics that took care of the whine…until it stopped working a few years later. I’m yet to replace it, and am dealing with the whine for the moment.
The subwoofer is a pretty cheap one, and as practicality took over, I found that I didn’t have room for a 2x12 ported box in the back of the Jeep. It has been sitting in my apartment for the past few years.
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Lighting
There are currently a pair of Hella 500’s on the bumper, a pair of dual beam round lights on the front of the roof rack, and a pair of 55w Hellas on the back of the roof rack attached to the reverse light circuit. The Hella 500’s come with great bulbs, have nice reflectors, and are low profile. I highly recommend them.
All forward-facing lights are on their own fused circuit, with the switch fed by the parking light circuit. The lights on the roof were initially controlled by a large switch panel mounted in front of the shifter. In the interest of space, I made a small control box that is mounted to the right of the steering wheel.
I initially made the mistake of putting fog lights and reverse lights under the bumpers. They were promptly smashed during off-road trips, and the locations were abandoned.
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Battery
With lots of lights, an aftermarket stereo, and a 2-level security system, a good battery is a necessity. I went through a couple of standard car batteries before I woke up and bought an Optima Yellow Top. It has been subjected to extended draws and never struggles to start the engine.
Loose Center Console Fix
One problem that most 97-01 XJ’s have is the loose center console. The Chrysler engineers had the bright idea of attaching the center console to the transmission hump with a few dinky sheet metal screws. Since the center console is subject to a decent amount of loading from elbows and other body parts, it doesn’t take long for the screws to come loose. It is stating the obvious for me to say that I replaced the screws with through-bolts and nylocks, but it’s here anyways. It’s a dirt simple job that requires a helper to hold one side of the bolts while you tighten them from underneath. A dab of silicone on each hole doesn’t hurt either.
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HVAC Recirculation without Air Conditioning
A “feature” of the 97-01 XJ’s HVAC system that always bothered me was the fact that you can’t use the recirculation mode without the A/C being on. Always a to-do in the back of my mind, I finally got around to it after having the Jeep for almost 5 years. It’s another very simple job. I wanted a self-contained job that would allow me to remove the HVAC control panel by only removing the harness. I found the A/C sense wire in my service manual and checked it by disconnecting the small green wire on the driver’s side of the panel. Upon confirming this, I disassembled the panel, which is laid out like a PC board without the board. It consists of a number of die-cut copper tracks that make the switch contacts, plug pins, and connections in between.
I cut the A/C sense conductor and put a small hole in both ends in a spot where I would be able to fit in wires. I could then make a solid solder joint on each. I then found a spot in the panel where I could drill through without interfering with any lights or anything inside. A basic RadioShack pushbutton switch finished off the installation. A lighted button would be nice, but I probably had a problem set to do, so the unlighted button sufficed.
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CB Radio
Although the cellular phones have mostly made the CB obsolete in passenger vehicles, the instant, simple communication of a CB can’t be beat. I had a nice Cobra 148GTL that I wanted to install, but it was far too big for the cramped XJ interior. I found a small RadioShack CB with weather channels and weather alert for under $100. I first mounted it on the dash in front of the passenger seat.
I was always worried about it interfering with the airbag or causing some kind of injury during a crash, so I finally moved it to the right side of the center console. Despite my initial concerns about taking up leg room, the placement turned out fine.
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Radar Detector
I suppose it’s a bit inappropriate to have a radar detector in a vehicle that has to be pushed to go over 75, but since I got the Jeep when I was at the end of my reckless driving days, it seemed to be a necessity. The Valentine One was an obvious choice, and was an easy install. It gets its power from a RJ-11 phone cord, which is easy to tuck into interior panels. It’s tied into the cigarette lighter circuit, which is only powered in ACC and RUN modes.
The Valentine is a great radar detector, which I highly recommend to those willing to shell out the big bucks for it. It has never failed me, and the direction indicator feature is very beneficial. The newer versions (one on the right) are slimmer than my ~5 year old one.
Safety/Recovery Equipment
No real Jeep is complete without a fire extinguisher and a first aid kit. I found that the passenger side corner of the trunk is a nice spot for both. (and I don’t need an odd looking bump in the tailgate like the Xterra!) A come-a-long also fits nicely under the spare tire. A tongue without a ball, and a shackle instead makes for a good, cheap rear recovery point. A high quality, good condition tow strap is also essential. I can attest to the uselessness of inexpensive tow straps (snnnnap!).
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Custom 4x4 Fabrications Parts
I got rear-ended on a trail in Hungry Valley, and instead of replacing the stock bumper, I got myself a Custom 4x4 Fabrications bumper. It’s a solid beast, and I’m actually concerned that it would do more damage to the uniframe in a serious crash. But then again, if it’s that serious, the uniframe is probably shot anyways. It did get a little test when I was towing a girl off of PCH, and she got distracted when her phone rang and smashed into me. The front of her Volvo was a bit smashed up, and my only damage was a few scratches in my Flowmaster sticker. That, and she ran over my tow strap.
One major feature my XJ lacked from the factory was front tow hooks. Rather than spend the exorbitant amount of money on the stock ones, I got a set of Custom 4x4 Fabrications ones for a fairly reasonable price. They’re beefy brackets, which are a lot more solid than the stock ones, and come with the extra front brackets that not all aftermarket kits include. The install was simple, with the most complicated (not really) part of the installation being the removal of the front bumper.
Once I had them installed, I found that the inside of my swaybar was hitting the heads of the rearmost bolts on the brackets. I emailed the company, and they recommended grinding the bolt heads, and said that it happens to a small number of people who use their kit. The Chrysler brackets come with round head Torx bolts, which have a lower profile, but I wouldn’t think about putting Torx hardware back on to the XJ. With new swaybar bushings, and a little grinding, I haven’t had any problems. I took the liberty (no pun intended) to trim the “excess” off the bumper ends and remove the airdam when I installed the hooks.
Skid Plates
My XJ didn’t come with any of the factory skid plates, so one of the first things I did to it was install the gas tank, front, and transfer case skids. The front skid isn’t very practical with a lift, because the diff sticks out a decent amount below it. The gas tank skid is pretty solid, but is a real pain to install with a hitch receiver attached to the same spot.
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Brakes
In the rear, I have the stock style drums. Nothing special there. It is worth noting that care should be taken when installing the rear tires, as the drums can shift slightly and end up off center of the wheel studs. This causes the bore for the stud to sit on the stud shoulder, and deforms it. After that happens, the drums are much less likely to seat properly.
I recently installed a set of PowerSlot slotted and coated rotors in the front with Hawk pads. My Chrysler recall rotors weren’t in great shape, and the cooling fins had some serious rust (fouling = bad heat exchanger). I figured that since the XJ’s brakes weren’t the greatest to begin with, I might as well improve the brakes since I often drive with heavier than average loads. They’re definitely better than what was on there, and seem to engage a little bit faster, but they didn’t provide any unexpected amazing results. The picture was taken right after the install, hence the lack of a wear pattern on the surface.
A while back I also put in Goodridge extended stainless brake lines to accommodate for future suspension changes, and to make working on it easier. With the stock lines and taller suspension, I found the stock lines near or at their limit with the uniframe jacked up. The braided stainless lines provided a noticeably stiffer pedal feel, and keep the brake fluid a lot cleaner.
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Exhaust
The stock XJ’s “stainless” exhaust system had holes in it after 3 years. Not knowing about the emissions warranty, and wanting to improve, I had a Flowmaster 40-series and high flow catalytic converter installed. Except for failing my smog check and hitting the “custom” headpipe with my front driveshaft, I have been happy with it. The junk Catco cat has since been replaced, and the shop that originally did the exhaust made a new headpipe…which also interfered with the driveshaft. I think the second cat is starting to go south, as the NOx levels are in the higher range, but I’ll find out when I get another smog check. Lesson learned: buy a good cat, and a pre-bent headpipe. If you look closely at the picture of my low pinion Dana 30 near the bottom of the page, you can see the dent in the headpipe.
Suspension
The suspension on my XJ is a combination of many additions and changes that were done at different times. It’s worth doing it right the first time...trust me.
If I could only get one message across with this section, it would be that Rough Country products are absolutely horrible, and under no circumstances should anyone support their company. They make an inferior product and refuse to stand behind it. My coil springs that were supposed to give me 3” of lift, gave less than 1”, and Rough Country insisted that they were the correct ones, and that I must be wrong. You get what you pay for.
I’ve got those coils, with about 2” of coil spacer. I am yet to replace the control arms, since I haven’t come across one I am completely happy with. I want something that can twist freely and doesn’t have “hard” joints (like heims). I was pretty sold on the Tera-Flex arms, but heard complaints about their seals and bushings.
Although I still have the stock control arms, I did replace the track bar with an adjustable one in an attempt to cure terrible “death wobble.” The first one I got was from Rocky Road Outfitters, made by Rusty’s. On RRO’s website, they claim that the adjustable trackbar is “a must for lifts over 3 inches.” What they don’t tell you is that the trackbar they sell is completely inappropriate for lifts 3” and down. In fact, it smashes into the diff cover every time the suspension hits a relatively large bump. RRO claimed that this was my mistake, and made no effort to rectify the situation. Thumbs down! It’s hard to miss in the pictures.
I have since replaced that one with a vastly superior Tera-Flex adjustable track bar. It has the appropriate bend around the diff, and is sleeved in the center like a drag link, so it can be adjusted without removing either end. I was still getting occasional disconcerting light wobbles every so often, so I pulled the lower half of the bar, and found that there was too much play in the rubber bushing. It also had a center sleeve that was bent from a flat piece of sheet, so it had a decent size groove in it. I didn’t have access to a press, so I had to cut the 3-layer rubber/metal bushing out. It was extremely difficult. I replaced it with a Daystar stock trackbar urethane lower bushing, and noticed definite improvements in bump handling. The urethane bushing is much stiffer, and has a continuous sleeve. Some of these pictures had to be rotated, which is why they have empty white spots.
My rear springs are Rancho 1.5” lift springs with full length add-a-leaves and 1.5” lift shackles, all held on with Rancho extended U-bolts. An odd combination indeed, but one that handles heavy loads fairly well. New stiffer packs are in order, but finances prohibit them at the moment. I made every effort to avoid the dreaded lift block. In hindsight, I could have spent the same money on a better pack, but live and learn. I went through a set of the Rancho urethane spring eye bushings fairly quickly. The second set has lasted longer, but the first got chewed up pretty quickly. Spring hanger and shackle bolt torque is important here to prevent excessive squeaking. And anti-seize on the bolts that go into the uniframe. If you’re lucky enough to get them out, be sure to put it on before they go back in. If they break the weld on the nut, you need to cut a hole in the floor to get to them.
I’ve got Rancho 9000’s in the front, 5000’s in the rear, and a 5000 steering stabilizer. In hindsight, it would have been worth getting 9000’s for the rear also. The rear shocks are spaced 1.5” from the uniframe to account for the bumpstop spacers.
In addition to the Daystar urethane trackbar bushing, I also replaced the swaybar bushings with Daystar urethane ones. The jury is still out on those. The install, which should have been simple, was complicated by the brackets not lining up with the holes. The slots in the brackets had to be hogged out a decent amount to get them to line up. They are extremely noisy sometimes. I used a liberal coating of the supplied “Lubrathane” grease, but they still squeak a lot, especially when cold. In hindsight, I should have gotten some Energy Suspension bushings that have zerks on them. The bushings for the swaybar links aren’t so great either. The bore in the swaybar is tapered, and the bushings have a 90 degree step on them. The poor fit is slightly visible in the picture below.
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Maintenance
Engine Oil Cooling System Axles/T-case/Transmission Air Filter Tires
Engine Oil
Oil changes every 3000 miles, always Castrol GTX 10W-30. It’s relatively cheap, and has a lower ash content than most non-synthetics. Synthetics have always been a little pricey for me.
I used to run a basic
Fram “Extra Guard” PH-16 filter…until I took one apart. Those things are
pathetic. Cardboard endcaps, stamped sheet metal spring, no anti-drainback
valve, cheap paper element. The “Tough Guard” TG-16 is a little better for a
few dollars more. It has a partially synthetic filter element, a bypass screen,
anti-drainback valve, and a higher claimed single pass efficiency. Availability
is also a concern, with Kragens everywhere, and NAPA’s far away. I figure that
with a short oil change interval, the GTX and the TG are doing fine.
I had a Fram
SureDrain drain plug/valve installed for a little while, but the thing took way
too long to drain because the ID of the valve was so small and restricted. I
was tired to waiting for it and wanted a magnetic drain plug, so the SureDrain
got ditched.
Cooling System
I change the coolant
and flush the system every 20,000 miles or so. Prestone anti-freeze has always been
the coolant of choice, and distilled water mixed 50/50 to keep the mineral
content to a minimum.
I put in a flush tee
in the heater line that connects to a garden hose to clean the junk out of the
system when I change the coolant. One unfortunate aspect of the flush tee is
that it runs cold water through the engine, so it never gets to operating
temperature, and stays in open-loop mode. That means less efficient cleaning,
and more unburned fuel into the catalytic converter and the environment. I never
get any nasty-looking water coming out when I flush it, but it still helps.
Near the end of 2004, the water pump started making a nice
high-pitched noise that followed the engine speed, and the pulley could be
rocked a little bit. I knew the bearings were trashed, but it had to wait until
I had time to replace it. When I took the radiator cap off, I noticed little
flakes of aluminum in the bottom of the filler neck. The bearings were worn to
the point that, with the belt tensioned, that the impeller started rubbing
against the pump casting, and took a few thousandths off of the surface.
Fortunately, the
seals remained intact. I was planning on getting a Flowkooler, but $110 for a
stock-style pump with a plate riveted to the back of the impeller didn’t make
sense, especially around money-hungry Christmas time. They claim something like
a 300% increase in flow at certain RPM’s. From what I can figure, the increase
just comes from the decrease in turbulence around the impeller. I was in a
hurry to replace the pump so I could drive out to Ocotillo Wells that weekend,
so a new $40 Bosch water pump fit the bill. The casting was a little sloppy on
the inside, but a few passes with the Dremel tool cleaned it up enough to
satisfy me. I certainly got enough practice with that kind of job with the WR
cylinder ports. I was a little disappointed that the more expensive Prestone
thermostat that I bought didn’t have a bleeder check valve in it. An
appropriately sized drill bit solved that problem easily.
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Axles/T-case/Transmission
Not much to say about
the axles. 80W90 GL5 every 40,000 miles or so. Blue RTV on the covers because
it’s the cheapest. I’ve got a low-pinion Dana 30 in the front (pictured on the left), which was
installed after I did something foolish and bent the stock housing (on the right)…don’t ask.
The transfer case
gets fresh Dexron III/Mercon every 20,000 miles.
The transmission is a
different story. Anyone who has spent a lot of time online looking at Jeep
message boards knows about this one. Chrysler incorrectly stated the
transmission oil type in a number of owner’s manuals. They call for a GL5-spec
gear oil. The problem there, is that GL5 oils have sulfur (hence the terrible
smell) in them as an extreme pressure additive for hypoid gears (differentials,
etc). That’s fine for non-synchronized gearboxes, but for synchronized
transmissions, the sulfur can deteriorate the brass synchros, shortening the
life and shifting quality of the transmission. The right oil is not easy to
find, and usually isn’t available at stores like Kragen and NAPA. I found
Redline MT-90 (fully synthetic) at a local shop for a mere $8/quart. My
transmission had quite a few miles on it with GL5 in it. It actually seems to
be a little stiffer with the MT-90 in it, but at least I know the synchros
aren’t getting eaten anymore. I’ve heard of people having luck with certain
types of Lucas and Royal Purple products also.
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Air Filter
I used to run Fram disposable air filters. I don’t think
they’re as bad as their oil filters, but certainly aren’t great. I got a UNI
dual element oiled foam filter near the beginning of 2004.
I was excited about
having a washable filter that I trusted in my dirtbike in the Jeep. The filter
left a bit to be desired, with its sealing lip not being completely even. I tried
many solutions, including loads of grease, a homemade cut-out rubber airbox
seal, and an RTV-based seal. I’m still working on perfecting the last one, as
it seems to accommodate the sealing irregularities the best. I filled the
sealing channel in the airbox lid with RTV, put a light coating of grease on
the filter lip as a release agent, and put them together. I would have just
gotten a cone filter and attached it to the intake duct, but the smog checkers
wouldn’t like it. I’m still looking for an inexpensive CARB approved intake
tube. Once I find one of those, I can just use a UNI cone filter.
I don’t trust
K&N-style gauze filters at all. Contaminants have one chance to get caught
in one layer of gauze, if they are not, they go through. With a foam filter,
there is a complicated, oil-impregnated path for the contaminants to follow,
and they are significantly less likely to go through. See the UNI website for
details. Besides, could every off-road rider be wrong?
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Tires
Of the four types of
tires I’ve had on the Jeep, I’m still looking for one I like. It came with
225/75/R15 Goodyear Wrangler RT/S tires. The tread wasn’t very deep, and with
about 50,000 miles of aggressive driving on them, they were pretty worn out.
The Goodyear Wrangler AT/S’s have a somewhat deeper tread, but also wore fairly
quickly. The next ones were 225/75/R15 Dunlop Radial Rovers. They were nothing
special, and I ripped the sidewall of one of them open on a chewed up curb. I
currently have a set of 30x9.5 Michelin XCL/APT’s on it. They were a second or
third choice since I was in a hurry and the Sears I got them from gave me
incorrect stock info on the phone. I should have spent the extra few buck on
some BFG’s, but live and learn. When they were new, they had a moderately
aggressive tread with a decent amount of depth. For a while, I couldn’t get
them balanced properly, and they would make ridiculous amounts of noise. It got
to the point that I had to wear earplugs on one long drive. I finally got them
balanced well and took care of some other issues, so they’re not too loud now.
Traction, on the other hand, is a different story. On dry pavement, they’re ok.
In dirt/mud, they do fine. On wet pavement, they’re terrible. Unintentional
burnouts and sliding await the unaware. I’m used to it by now, but the fact
remains that they suck in the rain.