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Answers to all your Jeep questions

Posted in How To: Tech Qa on December 13, 2015
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Dos Jeeps
I have a ’97 Cherokee XJ. I was replacing all the suspension bushings and found that the rear sway bar was broken. I checked online for anyone that makes suspension parts and found sway bars for many other model Jeeps but none for the XJ. Rough Country makes one, but it's for a lifted application. Do you know of any company that makes an OEM rear sway bar for a ’97 XJ?

Also, I recently purchased a ‘67 Jeep Gladiator and the floor in the cab is rotted out. Does anyone make replacement floors for this Jeep? Any help with this would be greatly appreciated.

And finally, great magazine. Awesome tech articles and advice.
Neran Persaud
Via email

The Cherokee XJ is probably one of the most successful Jeep models ever produced. If you can’t find a stack of used sway bars in the junkyard to choose from for a few dollars, you still have other options. Mopar ( offers the factory replacement rear sway bar (stabilizer bar) for the ’84-’01 XJ under PN 52001135. Prices vary from $70 to $120 online. If you are looking for something a bit stiffer for improved handling at speed, both ADDCO ( and Hellwig ( offer thicker aftermarket sway bars for the front and rear of the XJ. These heavy-duty sway bars are also useful if you regularly load your Jeep down with extra gear, making it more top-heavy.

The rotted floors of your Gladiator can be easily replaced with patch panels. BJ’s Off-Road ( has a full line of FSJ repair panels, including 18-gauge cold-rolled steel front floor pans. These patch panels fit every FSJ ever made including the ’63-’83 Wagoneer, ’84-’91 Grand Wagoneer, ’74-’83 Cherokee, and ’63-’87 J-trucks. The floor panels are hand made in the USA and cover from the front firewall seam to the front of the front seat and from the rocker panel pinch weld to the transmission hump. Both passenger and driver side panels are available.

The front floor pans of FSJ Jeeps often have rust problems. Water leaks in the door and windshield seals are the primary cause. Once water gets the carpet wet, the area stays damp for a long time. Dirt and salt from your shoes speeds up the process. BJ’s Off-Road offers new door seals as well as new windshield gaskets. If yours are leaking, it might be time to replace them.

Finding the leaky areas is easy. You can simply sit inside the vehicle and have a buddy hose down the Jeep while you check for water running in. On an FSJ, it’s usually very apparent where the water is coming from. There are not a lot of interior cover panels blocking your view to the seal surfaces.

EFI Conversion
I have a question regarding a fuel-injection conversion for my ’87 YJ with a 4.2L inline-six. What brand conversions have you dealt with or recommend? I know Mopar makes one and Howell makes one. Are there any others that you know of?
Chris Toth
Via email

The Carter carburetors that came on the 4.2L, 252ci, and 232ci inline-six engines in the YJ and CJ were absolutely terrible, even on street-driven Jeeps. It’s no wonder there were so many fuel-injection and carburetor replacement kits offered for these applications. I actually had a chance to get behind the wheel of several of the available kits.

The Holley ( single-barrel Pro-Jection kit is probably the most archaic of the bunch. It is based on the GM single-barrel throttle body and requires the user to at least have some knowledge about tuning the fuel adjustment knobs manually. It allows the engine to start easily and run at all angles, but it doesn’t provide ultimate performance. The kit has long since been discontinued, but you can still find used kits and new replacement parts for sale online. You might be able to adapt the Holley Avenger two-barrel EFI kit (PN 550-200) to your engine, but it would require some thought and would not be a bolt-on deal.

The Mopar ( MPI kit is perhaps the most complex and certainly the most expensive of all the EFI kits offered for the Jeep inline-six engines. It requires the installation of a new multi-point intake manifold, among other things. The system works well, runs smooth, and makes good power at all rpm ranges, but it also causes detonation on some engines. The complexity and cost are huge deterrents.

Dollar for dollar, the most cost-effective kit I have used on the carbureted Jeep inline-six is the Howell EFI ( kit. It’s based on a GM TBI and bolts to your intake manifold. The kits are still available today in 50-state smog-legal and off-road versions. Each kit includes all the components you need, along with a remanufactured 4.3L Chevrolet throttle body. Many of the original emission controls are eliminated, which cleans up and simplifies the space under the hood. The new ECM installs under the dash and a high-pressure fuel pump must be installed in the main fuel line from the tank. A bypass fuel line is returned to the tank. The wiring harness includes a diagnostic connector that is similar to what you would find on an ’86-’92 GM pickup truck.

Fast ( offers a self-learning EZ-EFI kit for the ’72-’91 Jeep CJ and YJ 4.2L inline-six, but I have not used it.Link text....

Wheel Around
I just purchased new wheels. The label on the wheels and the installation instructions say that the wheels are rated for 1,400 pounds with a 30-inch tire. I’m mounting 35x12.50-15 tires on a vehicle with a GVW of 4,600 pounds. Is this a good idea?
Joe Risser
Via email

All wheels have a load rating, and some wheel manufacturers have tire-size limitations. I’ll generally steer clear of these wheels if they don’t allow the tire size I want to use. It’s not that the wheels are weak and are going to break, but the manufacturer clearly did not intend for anyone to install tires larger than the recommended size. A larger diameter tire has more leverage on the wheel and creates more stress. Personally, I’m not interested in being the one to find out if questionable wheels are strong enough or not. It’s a good idea to do lots of research before settling on a set of tires and wheels. The looks of the wheel may be important, but the strength should be higher up on the priority list.

Hot Air 4.0L
I have a ’00 Jeep Wrangler TJ with the 4.0L inline six. I have aftermarket high-cut fenders and a short intake with a K&N filter. This combo is definitely causing the engine to suck in lots of hot air. Any ideas on how to suck up cooler air into the engine?
Bill Adelmann
Temecula, CA

Routing cold air to the intake of any engine will help increase fuel economy and power output. This can be done in many different ways. The most cost-effective method involves using underhood shielding to section off the air filter from the rest of the engine compartment. You can use aluminum or plastic to build your own custom shielding that allows air to flow through the grille or inner fender and onto the filter. However, if you frequent deep-water crossings, you really don’t want the water to have a short cut to your air intake.

Adding a snorkel like those from ARB ( is another method of getting clean, dry, cool air to your engine. However, snorkels may impede airflow and reduce power output, but they will generally keep you from sucking water into your engine, which is certainly more important.

Another option is to build your own custom intake system and route the air filter to the inside of the cab or elsewhere on the vehicle. This can be a costly and complicated option. Airaid ( and Summit Racing ( both offer universal tubes and couplers that can be used to build a sealed air intake if you decide to go this route.

Ultimately, with a 4.0L under the hood, you really aren’t loosing enough horsepower or fuel economy to justify the expense of some of these options. Personally, I like to keep my air filter shielded from mud and water. To me, that’s much more important than bringing in cool air and making peak power. If I only drove on the street I might feel differently.

FSJ Info
I have a few tech questions about my ’64 Jeep Gladiator:
1. My Jeep has Dana 44 front and rear axles. What weight of gear oil is best for them?
2. I want to rewire my Jeep. The gauges and most of the other electrical accessories do not work. How will I gain access to where the wires enter the cab?
3. I need to redo the drum brakes. Do you know of any place where I could acquire a rebuild kit or the necessary components?
4. What transmission could this Jeep have in it?
Aaron Smythe
Via email

Your ’64 Jeep Gladiator pickup is great vehicle to learn wrenching and wiring basics. The vehicle is incredibly simple and straightforward. The Dana 44 axles in your Jeep, and pretty much all Dana 44 axles, are not too particular about the gear oil you put in them. I would recommend 80-90W gear oil from your favorite manufacturer. Synthetic oil is not necessary but you can run it if you choose to. Gear oil brand and type isn’t as important as keeping it clean and properly filled. Gear oil contaminated with water or mud will quickly degrade the ring-and-pinion gearset and the differential bearings.

There are many different ways to run the wires through the firewall of the cab. The simplest way is to simply drill a hole and use a grommet or wire loom to protect the wires. Companies like Painless Performance ( offer complete Jeep-specific and universal wiring harnesses with fuse blocks that mount to the firewall. You can also purchase individual components from the company if you don’t want a complete wiring harness.

Napa ( and Rock Auto ( carry a pretty good selection of brake parts including new brake shoes, wheel cylinders, and drums. You may have to shop around a bit to find some of the brake hardware if yours is unusable, but it’s out there and can be purchased relatively inexpensively.

Your ’64 Jeep Gladiator could have come with one of four different transmissions. The standard transmission with the inline-six was the three-speed Warner Gear T-90A. The V-8 model came standard with the three-speed Warner Gear T-85. An optional Warner Gear T-98 four-speed was available, as was a Borg Warner AS-8W automatic transmission.

First Timer
I just recently bought my very first Jeep, a forest green ‘98 XJ Cherokee Classic. I love it. Like every other Jeep owner, I dream of off-road glory, but plan on using it as a daily driver, at least for now. Where should I start my off-road journey while staying road-worthy and budget-friendly?
David Draper
New Philadelphia, OH

The XJ Cherokee is a good first Jeep to use as a daily driver. The ’97-’01 models are the best of the breed. My advice would be to start with the basics. Make sure the Jeep is in good working order. Repair any excessive oil leaks and extend drivetrain breather lines if you plan on encountering deep water or mud crossings. I would invest in a set of quality all-terrain tires to help get farther down the trail. Always carry a fullsize spare tire.

Install recovery points front and rear because you or a buddy will eventually get stuck. Having the proper tow points could mean the difference between getting out easily and damaging your new-to-you Jeep during the recovery. It’s not a question of if you will get stuck but a question of when. Rugged Ridge ( offers a bolt-on front tow hook kit that fits the ’84-’01 XJ Cherokee under PN 11236.05. Out back you can use a factory or aftermarket tow hitch with a receiver shackle.

Purchase a quality recovery strap. There are many different sizes and types to choose from. If your primary off-road areas consist of deep sticky mud or bottomless sand, consider a kinetic energy recovery rope like a Bubba Rope ( Avoid tow straps with metal hook ends. These can become unhooked during a recovery and become a dangerous projectile.

Start off by tackling simple trails. Learn what your Jeep can and can’t do. Hone your off-road driving skills and modify your Jeep as you go. You’re first big purchase should be a pair of quality rocker guards. The rocker area of nearly all 4x4s is susceptible to damage off-road. Rocker guards are cheap insurance that should help keep your Jeep out of the body shop.

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