Suspension

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FSJ suspensions consist of  a spring-under front and spring-over rear axles. FSJ's equipped with QuadraTrac full time four wheel drive used an unique pair of Dana 44 axles that had offset pumpkins, whereas those equipped with either SelecTrac or CommandTrac part time four wheel drive had a Dana 44 front axle and an AMC Corporate model 20 rear axle. The SelectTrac units used a vacuum disconnect front axle similar in design to that used in the later YJ Wranglers, whereas the CommandTrac units used a conventional axle design with lockout hubs. To make things even more confusing, front axles came in two available widths: a Narrow Track on the Wagoneers and model 15 and 16 Cherokees, and a 6" wider Wide Track axle on the model 17  Cherokee Chiefs and J-trucks. The rear axles came in three widths: a Narrow Track, a Wide Track, and a wider J-truck version. For some inexplicable reason that was unknown (or unadmitted) by the previous owner, the Chief came with a vacuum disconnect Narrow Track front axle and a Narrow Track rear axle - similar to that in a Selectrac-equipped Wagoneer. It was obvious that these were not the original axles because the VIN and part time NP 208 transfer case both pointed to a Command Trac setup. It was a bit disappointing to find that I didn't quite have a Cherokee Chief, but the axles worked - so I decided to live with them until something happened. 

When I bought the Jeep the front axle would not engage when the transfer case was shifted into four wheel drive. The reason was clear when the front differential cover was removed. The vacuum disconnect front axle used a switched vacuum source to move a shift fork within the axle housing that moves a sliding splined sleeve to connect the driverside and passengerside axles together. Because my Jeep did not have the necessary vacuum assemblies the input hoses to the differential housing had been blocked off my the previous owner. Without vacuum the shift fork rests with the sleeve in the disconnected position. I permanently engaged the sleeve in the connected position by welding the fork mechanism to the inside of the diff cover while in the engaged position. Unfortunately this quirky version of the Dana 44  had driverside and passengerside inner axles that were of different sizes. that meant that the ARB locker that I had already bought did not fit! Reluctantly I installed a EZ -Locker.

FSJ's still sitting on aging original springs are prone to the infamous "Wag Sag" as the rear springs sag. This is most pronounced on the driverside - perhaps due to the location of the gas tank or to the weight of the driver. My Chief was no exception.

The original 15X8 wagon wheels were originally equipped with 31 inch tall tires. The tires on the Chief were bald and rotting. I was able to get a set of used 32" BF Goodrich Mud Terrains and mounted them on new Outlaw II 15X8 wheels. Here's some pictures of the Chief after it was done and running, equipped with a 2" body lift and the stock springs. The 32's fit well, but you can see that it still has the definite Waggy Saggy.

I wanted to fit 35" Goodyear MTR tires without fender rubbing, and decided that the combination of the 2" Performance Accessories body lift and a stout 4" spring suspension lift would be sufficient. I wanted to replace the aging rear springs, so simply using a add-a -leaf or block was not an option. I had heard and read many good things about the 4" spring lift kit by SkyJacker, but was a little leery about the stories of SkyJacker springs sagging with time, and that spring wedges were frequently necessary to restore front axle caster and rear pinion angles back to original. I spec'd out a complete kit with shocks, lengthened stainless steel brake lines, and a dropped pitman arm, and was shocked with the $1000 estimate from SkyJacker. Similar kits from SuperLift and Rough Country were ruled out due to their reputation for a harsh ride. 

Two other companies seemed promising: Big Dicks Suspension (BDS) and a new kit from Rusty's Offroad. Based out of Coldwater, Michigan the BDS plant used to make kits for Trailmaster until Trailmaster relocated its facilities to California. After talking to a tech representative, it appeared that the BDS kits had all the good design characteristics of other well thought out modern spring designs, and a good price of $599 without shocks, pitman arm, and brake lines. Rusty's Offroad, based in Alabama, is a relative newcomer whose rising reputation is based on their unique XJ and TJ suspension products. The company is small, and Rusty personally answers the phone calls. I saw a few reports of poor service and delivery, but I also heard that Rusty personally trail tests each kit design and stands behind his work unconditionally. When I heard that Rusty was developing a 4" kit for FSJ's, I gave him a call. He said that a dropped pitman arm is unnecessary, and that his spring kit consists of 5 leaf front units and 7 leaf rears with includes an overload spring.  The warranty was as  good as BDS': If anything ever breaks he will replace it. Plus, his price was better: $499 including shocks! I ordered a kit and it arrived the next week.

The springs looked well made, with tapered leaves, Teflon inserts, and loose spring clamps. The center bolts of each spring were offset towards one end to maintain the correct caster and pinion angles without the use of wedges. They came with rubber bushings already pressed into one end, and new polyurethane bushings for the other. The original upper shackle and frame spring bushings were worn, and were replaced with new polyurethane units from ESPO.  I ordered a set of Earl's stainless steel brake lines separately from Four Wheel Parts Wholesalers, as well as a set of Rubicon Express 4" extended sway bar disconnects (spec'd originally for a CJ with the same amount of lift) and a Pro Comp replacement steering stabilizer.

Jeff's 4X4 did the install, and mounted the 35 x 12.50 Goodyear MTR's on the wheels. They also swapped out the original weak OEM Warn front hubs for all metal premium SuperWinch units, and modified the U-bolt pads and welded 1/4" plate to make integral U-bolt skid plates. I scarcely recognized the Chief when I returned to pick it up. The combination of the new tires and springs raised the Jeep 6 inches, and the Chief rode well with a hint of a buck-board ride (this was cured when I later switched the front shocks to Rancho 9000 units - pn# 9118). It sat slightly high in the tail - perfect for the weight of the extra parts and supplies that I would be carrying on the trail.

I took the Chief to Upper Tellico ORV in Murphy, North Carolina to see how it would do.  It flexed well...not as good as my TJ, but well enough that it never got high centered or stuck. Here's some pictures from Tellico showing the before and after:

The pounding at Tellico seemed to break in the springs, for now the ride is significantly smoother and softer, without any loss of height or Wag Sag.