What makes a great suspension? Is it the shocks? How about the control arms? Could it be the way it’s designed? The simple fact is that there are no one-size-fits-all suspension solutions. Guys that run in the deep swamps couldn’t care less about the low center of gravity that rockcrawlers rave about, and desert racers laugh at the trail wheelers that ride around on their bumpstops.
When we first began wrenching on our Rescued Wrangler project, our goal was to build a functional trail wheeler and make the most of the platform that we already had. This included the 2½-ton Rockwell axles that were already affixed under the Jeep when we purchased it. We’ve shown you how we’ve built the majority of our suspension system over the course of the buildup series, and now we are ready for the fine-tuning bits. The three main pieces that we are focusing on in this installment are the shocks, bumpstops, and limit straps.
While the role of the shock absorber is universally understood, you may be curious why we’ve dedicated such a large block to two pieces that are designed to limit the wheel travel. Part of the challenge of building a rig on Rockwell axles is working around the enormous top-loader third members. In our case, we were not looking to build a sky-high mud bogger, so we worked to maintain a low and wide vehicle stance. This presented a packaging challenge, mostly due to the fact that if the axles were able to cycle freely upwards, damage to the rig’s vitals (such as the oil pan and radiator) would occur. Installing bumpstops easily prevents the axles from moving beyond where we want them to.
Our primary goal with the limit straps was to reduce the chance of our coils and shocks from being overextended and damaged. We are currently working with around 8 inches of vertical wheeltravel. This may not sound like a lot, but there are a few factors to consider. Given that the 44-inch Pit Bull Rockers have a healthy amount of sidewall on our 15-inch The Off-Road Connection-sourced beadlock wheels, they act as a secondary suspension of sorts. This means the tires provide additional ride comfort and traction when placed at single-digit air pressures. The wide stance of our Wrangler also aids in making the Jeep extremely stable.
To accomplish our suspension-tuning goals, we spent some time on the rack at the host build shop, Low Range 4x4 in Wilmington, North Carolina. Owner Kelly Carter is familiar with a variety of purpose-built machines and was able to help craft our YJ’s suspension in a way that made it usable and controlled. There was no shortage of fabrication involved in this process, but the principles used are universally applicable. For those of you looking for the steering install we promised you in the last installment, don’t fret, as it will be in the following edition.
Step By Step
1. If you are looking to keep your vehicle low, but still retain a few inches of usable uptravel, you will likely need to trim and even relocate items under your rig. One obstruction we found was the stock rear crossmember. We trimmed away what we needed to and then fabricated a new crossmember directly behind it.
2. Bumpstops are designed to limit the uptravel of the suspension and to save components from being damaged. For our YJ, we used Daystar Products slotted-mount, comp-style bumpstops (part# KU09017BK). To secure the 3-inch-tall high-impact polyurethane bumps, we cut and drilled sections of 1/4-inch flat bar.
3. After we determined exactly how much uptravel we could squeeze out of the rear suspension, we fabricated the bumpstop mounts using 1 3/4-inch, 0.120-wall DOM tubing. For strength, we tied the bumpstop mounts to the new and stock rear crossmembers. The distance inboard or outboard that you place the bumpstop will make a difference in how they perform. Be sure to cycle your suspension vertically as a unit and individually to see how the bump and axle reacts. You may find you don’t have clearance issues during vertical compression, but when the axle is twisted (vehicle articulating) contact issues may arise.
4. We wanted the Jeep to sit as low as possible for the benefit of stability and performance. Generally, your tires will be the major limiting factor to achieving a low stance, but in our case, the 44-inch Pit Bull Rockers had plenty of breathing room. The extremely tall third member and Ouverson pinion brake, on the other hand, rests very close to the engine, frame, and radiator at ride height, so proper bumpstop placement was crucial. We built bumpstop contact pads on the axle to offer a solid place for each to hit and not become damaged. Be sure to factor in the amount that the bumpstop collapses, as not all are alike. Our Daystars compressed a little over one inch.
5. Similar to our Ballistic Fabrication adjustable coil buckets, the company also offers adjustable shock towers. We had to trim a little out of our inner wheelwell to make room for the Ballistic towers, but overall, the fit was perfect for our application. In addition to standard shocks, the Ballistic towers are also suitable for coilovers as well.
6. When dealing with axles as heavy as our 2 1/2-ton Rockwells, limit straps are an absolute must. Limit straps keep the axle, shocks, links, and additional components such as driveshafts and brake lines from being overextended. While a single six-ply Trail-Gear strap at each corner would have probably been sufficient, we decided to add an extra strap to each corner for when our inner hillbilly takes control and puts the YJ somewhere it wasn’t meant to be. Each of the Trail-Gear straps are rated at 9,000 pounds, fitted with 4130 heat-treated chromoly buckles, and offered in 8- to 40-inch lengths.
7. With such a relatively light body and heavy axles, a standard Jeep Wrangler YJ shock’s valving wouldn’t be ideal for our application. We contacted Zone Offroad Products for a shock suggestion and the company recommended its 7760 twin-tube gas shock. So far, the med-firm valving of the 7760s seems to work well with our 3 1/2-inch-lift BDS Suspension TJ coil springs. Once we get out on the trail, we can make the best evaluation if the budget-friendly shocks will work for our needs.
8. Out back, we fabricated 1/4-inch tabs to the rollcage braces and axle, and then bolted in the Zone 7760 shocks. We are not running sway bars on our trail rig, and found that mounting the shocks more vertically and outboard helped with stability. Given the tremendous width of the Rockwell axle, we had plenty of options for where to mount all of our suspension components.
9. Once we got more weight in the Jeep, we found the rear was sagging a bit more than we liked. Our level solution came by way of a set of 1 3/4-inch Daystar coil spacers.
10. We needed a solid recovery point on the front of the Jeep as well as a bumper that wouldn’t rob much clearance. The BFH front bumper from Poison Spyder Customs fit our needs perfectly. Since the 3⁄16-inch steel front bumper came bare, we had our friends at Area 51 Powder Coating in Holly Ridge, North Carolina, fit it with a nice semi-gloss finish.
11. Sticking with our budget-friendly theme, we went with 10,000-pound Warn VR-series winch. The VR10000 is part of the company’s most affordable line of winches and is fitted with a three-stage planetary geartrain, which host a 261:1 ratio. We also opted for the steel-cable-equipped version for the rugged durability and value.
Clackamas, OR 97015
Zone Offroad Products