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February 2013 Firing Order

129 1302 01 February 2013 Firing Order Rig Winching Up Rocks
John Cappa | Writer
Posted February 1, 2013

Suspension Compromises

When fabricating and assembling my Jeep’s suspension system, I was apparently as meticulous as an engineer installing O-rings on the solid rocket boosters of the Challenger space shuttle. Even though I had done tons of research, looked at hundreds of photos, and read every off-road magazine I could get my hands on, I still could not predict the disastrous results of my labor. Fortunately, this was nearly a decade before you could do an Internet search, because if it were possible at the time, there would have been numerous knucklehead forum bandits recommending things like Metal Made Rite Revolver Shackles, which would surely have exacerbated my problems.

Anyway, I had torn my Jeep down to the bare frame, swapped in a V-8, added a custom leaf-spring suspension, bolted in different axles, and added bigger tires. At that point the hot ticket was to fabricate mounts and install soft, compliant Wrangler YJ leaf springs in a spring-over fashion. This common setup was typically dampened with Rancho RS9000 adjustable shocks mounted upside down to protect the cans from rock damage—so that’s exactly what I did on my Jeep, too. I spent a ton of time boxing and reinforcing the frame, calculating, measuring, welding, and double-checking everything as the chassis came together. Being a dumb kid with plenty of time, I was able to finish my Jeep in a matter of weeks. I worked so feverishly that I had just about worn the fingerprints off of my fingers. I remember having a really hard time with the wiring because my fingertips were so thrashed with cuts and burns.

What’s the best lift kit for my...

When I was done, I hopped in the driver seat, fired the engine, and pulled out of the garage. Of course, I really wanted to get a feel for the newfound power of the V-8 under the hood (the Jeep previously had a tired V-6). I pulled to the bottom of the driveway, pointed the Jeep up the street, and laid into the throttle. What resulted was and probably still is one of the most frightening driving experiences of my life. Due to the extremely compliant suspension and increased torque, the driver-side front tire came up off the ground about a foot while the Detroit Locker and rear bias-ply tires with mismatched air pressures caused the Jeep to violently veer to the left. With my eyes as big as saucers and my buddy rolling over laughing in the driveway, I juggled the steering wheel to keep from slamming into the neighbor’s parked car on the other side of the street, all while trying to look cool and remain calm. Of course, being young, dumb, and scared out of my wits, I did what any sane individual would do—I grabbed Second gear and pinned the throttle again with similar results. Only this time I could hear the unmistakable rattle and vibration of a rear driveshaft binding in the axle yoke, no doubt caused by massive axlewrap. By this time I had reached the top of the hill and I was doing some serious head scratching. I wondered how it was that all of these guys with similar setups were able to drive their Jeeps on the street like this. I later found out that very few of them did, and that I had some “tuning” to do.

I headed back to the garage to make alterations. I went through several different traction bar designs. The first few attempts still allowed the rear driveshaft to bind under heavy throttle use. These designs worked for some people and the kind of wheeling they did, but not for me. I left a couple of driveshafts and a scattered transmission in the sand because of too much axlewrap, although I eventually found a way to get it under control. I also figured out that contrary to popular belief, you can’t mount all Rancho RS9000 shocks upside down. They would get air pockets in them which resulted in several inches of undampened suspension movement, making my particular Jeep very tipsy. Flipping the shocks right side up made them much more effective. By the time I was done tuning, my Jeep had 10 inches of useable front wheeltravel and about 12 inches in the rear. The suspension cycled and articulated over obstacles well. It could even hit mild bumps at speed and drive down the highway somewhat safely. I mean, I wouldn’t toss the keys to my mom or anything, but it was impressive for a Jeep with only a 79-inch wheelbase. In the end, it still had front axlewrap that required me to go easy on the throttle in the dunes. The rear traction bar kept my driveshaft from binding and flinging out from under the Jeep, but it would bind and limit suspension movement. Every few months of hard wheeling it caused the driver-side rear main leaf to kink and snap.

My Jeep’s suspension wasn’t perfect; in fact, it was far from it. But at the time it worked for me and my budget. Looking back now, I might have been better off sticking with the stock suspension design and added a pair of bolt-on aftermarket leaf springs. Had I gone that route, I wouldn’t have learned as much as I did about what would work off-road and what wouldn’t, though. Ultimately, there is a compromise to every suspension modification you make on your 4x4. I’m often asked: “What’s the best lift kit for my XYZ?” I can’t always answer a question like that. There are just too many variables. Everyone has a different idea about how the vehicle should ride, drive, steer, and so on. Quirks that you may be willing to put up with may be absolutely unbearable to me. There is no magic-bullet suspension lift kit or system that does everything well, and even if you build it yourself like I did, you’ll still have to make compromises.

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