The jeepfan.com 1978 CJ-5 gets the full treatment. Installation of front and rear ARB Air Lockers and late model CJ wide track axles.
I always had minor issues with my 78 CJ-5 on the trail. First of all, CJ-5s all used the “narrow trak” axles, the nice thing about this is that you can run with wide tires and they do not stick out the side of the body and throw the goop all over. The bad thing, and there are several bad things are as follows. I’ll start with the front. Your nice big wide tires like to rub the paint off the springs and you need more practice with the “K” turn due to the fact that the Jeep’s turning radius stinks. Now in the back, the tires rub the insides of the fenderwells, frame, and whatever else gets in the way. Overall the narrow axles make the Jeep a bit more top heavy and the higher the lift on the Jeep gets the pucker factor in those off camber situations grow exponentially.
CJ-7s made after 1983 used the “Wide Trak” axles, these totaled about 5 inches (2.5 per side) wider then their “Narrow Trak” cousins. After a bit of research I discovered that a set of Wide Traks could essentially bolt in place of the narrows. I decided I would do it, so after a little spreading of the word and calling around I was alerted to a 1984 CJ-7 that was parting-out. The CJ had a broken frame but everything else was in good shape, so I bought them and ran home.
I suspected the gear ratios to be the dreaded 2.72 ratio, and it was so I had to think a while what to do next. Originally I intended to install a set of 3.73 gears and reinstall my Detroit EZ-Locker. Considering the fact that I would need to have the ring & pinions set up regardless of what gears I used I decided an upgrade was needed.
To start off with the Detroit EZ-Locker was a great improvement off-road but the on road performance in my little CJ-5 was not very pleasant. The Jeep did instant lane changes when shifting, decelerating, and cornering. In the rain or snow it was almost scary. Tire wear on the rear tires was greater too. One thing that I did like about it was the clicking noise during corning. I think that I noticed the effects of the locker more due to the fact that my CJ is shorter than a 7 and lighter because of the fiberglass body. Now I don’t mean to trash on this fine locker, because it served my Jeep and me flawlessly and the price and ease of installation make it worth every penny.
The only real alternative to a automatic locker is the ARB Air Locker, sure they are big bucks and require additional accessories, but us Jeep people know that having a Jeep means having no “Extra” money. For those of you who don’t know what an ARB Air Locker is or how it works click here.
I decided to keep my 3.54 gears and install them with the Air Lockers into the new axles. I also decided to keep the front a rear brakes from my CJ. 78 and earlier CJ’s used the 11″ by 2″ rear drum brakes which provide more braking power than the 10″ by 1.5″ brakes used on later models. Fortunately they fit the axles the same and are interchangeable. On the front I am going to reuse the whole outer spindle assembly, on 80 and older CJ’s these Jeeps use the 6 bolt hubs and also use the thicker disc brake rotors.
Getting Started
As always I gave a call to OK Auto and started ordering stuff. I ordered the rear ARB and a set of the Superior 1 piece axles. Meanwhile I worked on the disassembly of both the front and rear wide trak axles. The front axle was disgusting, it looked like it took on water and the water and oil made a milk chocolate goo. Needless to say but the bearings and seals were shot. Oh well it did not matter, I was replacing all of this anyway. The rear axle was in good shape and just needed a good cleaning. I completely disassembled both the axles and cleaned them inside and out. I then applied a nice fresh coat of paint.
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I have never set up a ring & pinion and I do not have the tools necessary to do the job right. I loaded up the rear axle and off to OK Auto it went and a few days later I picked up the axle, all ready to be finished. OK did a nice job for me, they installed new bearings and seals, drilled and tapped the axle housing for the air fitting, and installed the ARB air line. Now I had the new bearings pressed onto the new axles and in they went. I installed a new gasket, replaced the diff cover, and added oil. I bought all new brake parts and installed them. After a touch up with some paint it was ready to go back into the Jeep.
After the axle was reinstalled there was a noticeable difference in the width of the rear. My tires now stuck out of the wheelwells about 3/4 in. The Jeep looked good. After a little admiring it was back to work. I had to run the air line up the the engine compartment to attach it to the compressor. I decided to install the line inside 5/16 inch steel tubing for protection. The line runs up the passenger side frame rail and exits the tubing right next to the ARB Air Compressor which I mounted to the battery tray.
I wired up the compressor, which by the way, came with an excellent made wiring harness that is designed to use a front and rear locker. I fabricated a new switch panel for my dash to hold the nice looking ARB switches plus some other things. I connected the rear locker valve (which needs to be installed the right direction, hmm hmm), the quick connect air fitting, and the pressure switch.
I tested the locker, it worked, and after some final things like bleeding the brakes, checking bolts, etc. it was time for a ride. It felt like a different Jeep. It was smooth and lacked the jerkiness of the old locker. I pulled into a gravel parking lot and engaged the rear locker. I made no sound but the rear axle was locked solid. Turning in the gravel showed the inner tire dragging and ripping up the ground. I did a few hole shots and left a couple of nice trails of tire marks. It seems part one of this project was a success.
The Front
I finally installed the front locker. I took the Jeep for a spin, it felt good. The Jeep looked really cool from the front now, the wide axles made the Jeep look bigger. I wandered down in my back yard for a fully locked test.
The ARB wiring harness is designed to only allows the front locker to be engaged when the rear one is. I was told this was easily remedied but I left it alone for now. I turned in the Jeep’s hubs, engaged low range, and locked the sucker up. The initial thing I noticed was that the Jeep was damn near impossible to steer while sitting still. Moving made things easier but I could not imagine driving with the front locker on all day during a trail ride. I have a small rock pile in my yard for testing, immediately I noticed the front tires crawled up on the rocks much easier due to the front locker and there was no tire spin. I was impressed, now I was anxious to try them out on a real trail.
Here is a few pictures of the Jeep completed.
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OK 4wd in NJ has an annual event called Day Kamp & Rock Krawl (see the offroading adventures section) This event was being held only about 2 weeks after the Jeep was finally together. Here was my chance for a test. See the Fall Krawl page for details.
After several outings the ARB’s are worth it, I have greater control while turning and on off-camber situations. The Jeep does not slide as easily, unless I want it to and the wide track axles make the Jeep seem more stable.
