Located in the heart of four-wheeling country, Canyon State Components is owned and operated by two dedicated off-road enthusiasts. Fred Swanson and Jim Allen have become notorious in the off-road world for pushing the limits of their well-built 4x4s at off-road events all over the West. Canyon State's products are extensively tested on their own vehicles and as such they are proven to be able to stand up to the worst of the abuse that Arizona's notoriously harsh trails can dish out.

Background

Canyon State's latest products are a line of bolt-on suspension kits for short wheelbase 4x4s. Designed for maximum articulation and a smooth ride, these kits convert the front suspension of Jeep CJs, Toyota Land Cruisers and Suzuki Samurais to a shackle reversal setup, utilizing Jeep Wrangler leaf springs front and rear. The on- and off-road performance gains put the kits in the same league as much more expensive coil spring setups. With all the buzz that this new suspension kit has generated, Off-Road.com decided to test the setup on Project Buster -- a 1987 Samurai hardtop that serves duty not only as a hard-core trail machine, but also as a daily driver -- to see if this suspension lives up to expectations.

Design

The 1987-1995 Jeep YJ Wrangler is a larger and heavier vehicle than the 1986-95 Samurai so it comes equipped with much longer and wider leaf springs. The 37-inch long front and 39-inch long rear Samurai springs are quite stiff, creating the notoriously rough ride and limited articulation. The 46-inch long YJ springs not only allow much more articulation, but their extremely soft spring rate results in a much smoother ride.

Having witnessed how well Wrangler leaf springs work on custom-built vehicles that are designed for the most extreme trails, Canyon State wanted to develop an affordable kit that would allow the YJ springs to be bolted onto the Samurai. They knew that the Samurai could see tremendous gains in on- and off-road performance, but the springs' additional width and length meant that custom spring hangers had to be designed. Canyon State used this opportunity to take their suspension kit to the next level of performance by designing it to also be a shackle reversal setup.

Leaf springs are a very simple design, but their function is complex. Not only do they suspend the vehicle's body and frame above the axle and allow for the vertical movement of the wheels over bumps, but they are also the linkage by which the axle is located beneath the vehicle. By the nature of their arched design, leaf springs become longer as they are compressed and shorter as they expand, so a shackle must be used on one end of the spring to allow for this movement as the wheels travel over uneven surfaces. Thus, the springs create a diagonal movement of the axle as it travels up and down.

Why a shackle reversal? A normal front leaf spring setup is designed with the rear of the spring solidly mounted to the vehicle's frame while the pivoting shackle mount is located at the front of the spring. With this setup, the front of the spring moves forward as its corresponding wheel is compressed upward into the wheel well. Because the axle is bolted to the spring, it also moves forward as the spring is compressed. Conversely, when a wheel droops it pulls the spring downward, shortening the overall length and moving the axle slightly rearward.

With a shackle reversal, the spring's solid mount is moved to the front of the spring, while the shackle is relocated to the rear of the spring. This setup reverses the forward/rearward movement, causing the axle to move rearward as the spring compresses and forward as the spring droops.

The change in suspension geometry from a shackle reversal provides several benefits. Primarily, on- and off-road ride quality are improved because the front wheels move slightly rearward when they hit bumps, transferring less of a jolt through the vehicle to the passengers. Straight-line stability at higher speeds also improves due to the trailing shackle design. Additionally, placing a tire onto a large obstacle on the trail is made easier since the tire moves rearward as it compresses into the wheel well. The tire that climbs vertically no longer must work against the other three tires that travel horizontally, which causes a bind in the driveline that must be overcome with wheel spin.

With so many changes needing to be made to the suspension, Canyon State Components had to spend a great deal of time in the research, design and testing of their installation kit to ensure not only its durability on the trail, but also its ease of installation.

Installation

While Canyon State offers their front and rear Wrangler spring conversion parts separately for custom applications, their kit was primarily designed to be a complete suspension system. It should work with a stock SPUA (Spring Pad Under Axle) setup, but it was intended to complement the common SPOA (Spring Pad Over Axle) conversion.

Canyon State's front spring hangers extend the frame by approximately 3 inches to accommodate the additional length of the Wrangler springs. They replicate the stock bumper mounting holes, however, so any bumper that bolts to the stock location (including the stock, ARB and some Calmini bumpers) can be relocated without modification. Depending on the design of other aftermarket bumpers (such as the one from Wheeler's Off-Road with which our Samurai is equipped), some do not need to be relocated; a simple modification to the spring hangers can be pre-arranged with Canyon State to allow the bumper to remain bolted to the frame.

The kit comes with everything needed to install YJ springs onto a Samurai's frame and axles, including Grade-8 mounting hardware. However, items such as brake lines, shock absorbers, shock mounts, bump stops and drive shafts are not included because of the varying nature of the vehicles to be upgraded. Additionally, the Wrangler springs are not included because of the readily available choices that allow the suspension height to be tailored to individual's needs. Stock Wranglers have either four-leaf or five-leaf springs depending on their engine and any aftermarket YJ spring should also work with this kit.

I used Canyon State's complete front and rear kit along with some custom rear Missing Link shackles. I purchased two pairs of discarded stock five-leaf springs from a 4x4 shop for $100 and reused the shocks, shock mounts and brake lines from our previous suspension. Installation proceeded as follows:

Front

	Lift the front of the vehicle and place it securely by the frame on jack-stands, supporting the axle with a floor jack. Remove the wheels, U-bolts and spring plates. Note: The axle is removed for increased clarity in the photographs. This is not required for installation.
	Remove the shackles and spring hanger bolts so the old springs can be removed.
	Using a 7/16" drill bit, enlarge the four holes at the end of the frame.
	Insert the four steel bushings into the front upper shackle mounts on the frame, tapping them with a hammer if necessary.
	Bolt the new front spring hangers over the bushings using the supplied ½ inch bolts and through the upper frame holes using the 7/16" x 1" bolts. Use the 3/8" x 1" bolts for the lower inside frame holes. The front spring hanger installation is complete.
	Moving to the rear mount for the front springs, loosely bolt the four triangular steel plates through the existing one hole in each of the stock spring hangers. Clamp the plates to the spring hangers using vise grips to keep them aligned while drilling out the two remaining holes per plate with a 7/16" drill bit. Loosely bolt the supplied 7/16" x 1" hardware through the new holes.
	Mount the supplied shackles between the plates with the included 9/16" bolts such that the smooth side of the shackles (the side with the part number stamped into the metal) is oriented to the rear of the vehicle.
	Slide the Wrangler springs into the mounts, using the 9/16-inch bolts in the front solid mounts and the ½" bolts in the rear shackles.
	Position the axle with the spring centering bolt in the centering hole on the spring pad.
	Install the larger spring plate on the passenger side and the smaller spring plate on the driver side using the original U-bolts.
	Tighten all the nuts and bolts and then double-check them. Remount the wheels and carefully lower the front of the truck back down to the ground. Inspect the suspension.

Rear

	Lift the rear of the vehicle and place it securely by the frame on jack-stands, supporting the axle with a floor jack. Remove the wheels, U-bolts and spring plates. Note: The axle is removed for increased clarity in the photographs. This is not required for installation.
	Remove the shackles and spring hanger bolts so the old springs can be removed.
	Slide the new frame mounted spring hangers over the stock spring hangers, with the 2-inch tube (for the optional nerf bars) facing outward away from the frame. If the stock spring hangers have been bent from trail abuse, a large pair of pliers can be used to bend them back into shape. Insert the two black 12-point 7/16" bolts through the original spring holes on each spring hanger from the inside out.
	Drill the four 3/8" holes in each of the frame's box section to bolt the upper part of the new spring hangers to the frame with the supplied hardware.
	Insert the two sleeves into the upper rear shackle mount. This is the only part of the kit that must be welded. Allow them to cool before placing the bushings into the sleeves. Note: This step was skipped in this installation because custom-made Missing Link shackles were used.
	Slide the Wrangler springs into the mounts, using the 9/16" bolts in the front solid mounts and the ½" bolts in the rear shackles. Notice that the new spring hangers have two sets of spring mounting holes. The front holes are for Wrangler springs, while the rear holes are for CJ springs. Note: I installed my Wrangler springs in the rear CJ mounting holes to extend the wheelbase further.
	Position the axle with the spring centering bolt in the centering holes on the spring pads and the new wider spring plates and install with the stock U-bolts.
	Tighten all the nuts and bolts and then double-check them. Remount the wheels and carefully lower the front of the truck back down to the ground. Inspect the suspension.

Impressions

Buster's previous suspension used rear Rancho springs in front and front CJ springs in the rear with Missing Link shackles at all four corners, providing about 1.5" of lift over stock springs. The YJ springs lifted the truck an additional 1.5" for a total of 3" over stock, but due to the additional weight of the hardtop, roof rack and rear bumper, I had to use some very long rear shackles to level out the stance, as I did with our previous CJ springs. In the future, I may install a pair of 2-inch lift Wrangler springs in the rear with shorter shackles to improve the departure angle. Most Samurais will not have this minor problem.

Although our long rear shackles have hurt the departure angle, I'm very pleased with the front approach angle. Unlike the long "fangs" that protrude five inches below the stock shackle mount on another shackle reversal kit, Canyon State designed their front spring hangers to be only one inch lower than the stock upper shackle mount. The angle of the front springs allows them to easily slide up rocks until the tire can climb. Also improving the approach and departure angles is the extended wheelbase: With the rear springs bolted through the rear mounting holes in the spring hangers, I measured a three inch gain from the stock 79.9 inches.

The extended brake lines from my previous suspension setup have enough slack to accommodate the additional suspension travel. The upper shock mounts are also perfect for the new springs. I was able to reuse my Rancho 9112 shock absorbers at all four corners, but while testing articulation on the ramp I found that they limit droop by three inches, so a set of Rancho 9012's will be another future upgrade. I also learned from my tests on the ramp that even the heavier-duty 5-leaf springs that I used need bump stops to limit wheel travel; the tires easily stuff all the way into the body, forcing the springs into a severe negative arch that would eventually damage them.

Due to the amount of front suspension travel this shackle reversal provides, a new front drive shaft is absolutely necessary. Not only is the stock drive shaft too short for the extended wheelbase, but it also has only 3 inches of slip yoke travel. Additionally, the frame cross-member provides so little clearance for the drive shaft that it would cause the drive shaft to bind under maximum articulation. I purchased a new front drive shaft from Asian Auto Parts of Arizona (also available from Canyon State Components) that is custom-made for this suspension kit. Its compressed length is about one inch shorter than stock, but thanks to its 10-inch slip yoke, its extended length is about six inches longer than stock. It is also designed with a narrow upper section to allow full suspension travel without requiring the frame cross-member to be modified. The tiny stock U-joints are replaced with Spicer 1310's to ensure long life and dependability, with machined flanges that allow maximum articulation and that bolt to the stock transfer case and pinion flanges.

In back I re-used the stock rear drive shaft. However, to accommodate the extended wheelbase I used the Trail Tough 2" extended slip yoke from my now-unused stock front drive shaft.

On-Road Performance

The improvement in ride quality is immediately apparent. Even with the adjustable Rancho shocks set to their stiffest setting, the ride has none of the harsh jolts for which the Samurai is known. At the shocks' softest setting, bumps are hardly felt; the body just floats over potholes and railroad crossings and even the street reflectors between lanes are hardly perceptible.

Cornering is smooth and predictable. I was pleasantly surprised to find that our Samurai no longer needs the pan-hard bar that we had installed to control our previous suspension's behavior. Straight-line stability is also substantially increased, due to the new pinion angle's positive effect on the steering castor and by nature of the trailing shackle's dynamics. The Samurai now tracks straight ahead in its lane instead of requiring constant steering correction. Another positive side effect of the increased castor is the reduced turning circle. The front tires visibly lean into the turn as they pull the front end around as tightly as possible.

A tradeoff that comes with any tall, softly-sprung vehicle not equipped with anti-sway bars is increased body weight transfer. A factor of the springs' softness, acceleration, braking and cornering forces create a more pronounced movement of the body on the suspension. Although the increased suspension squat, dive and lean do not adversely affect the drivability of the vehicle, the increased body motions do take some time to become accustomed to. It is for this reason that Canyon State recommends using the adjustable Rancho 9000-series shock absorbers for optimal suspension control in both on- and off-road environments.

I can confirm that the Rancho 9000s tighten up the handling quite nicely when adjusted to a stiffer damping rate. On windy mountain roads, I can attack the corners with as much speed as before, while on rougher roads the shocks' softer settings hide all but the most severe bumps. Off-road, however, is where the new suspension really shines.

Off-Road Performance

As we expected, the soft springs and tremendous wheel travel make for an unbelievably comfortable and virtually unstoppable vehicle.

Many of the best 4x4 trails are accessed by long unpaved roads that are rough enough to rattle fillings loose. Washboard surfaces are the worst, but with Canyon State's suspension and the Rancho shocks at a soft setting, my Samurai can drive along these roads as if they were paved. The ride is so smooth that I can drive comfortably at double the speed at which I could with the previous suspension. Even large bumps do not pose a problem since there is so much wheel travel available from the springs.

It is this wheel travel at high speeds which also makes the truck so capable while crawling along on the toughest of trails. With over 40 inches of articulation (approximately 1500-1600 RTI on a 20-degree ramp) all 4 wheels stay firmly planted on the ground, maximizing stability and traction. Even with the too-short shocks limiting wheel travel, Project Buster never lifted a tire off the ground on Arizona's 4.5-rated trails.

Rock crawling is easier with the improved approach angle and the shackle reversal works very well when placing the front tires on large rocks. The springs' rearward movement under compression means that the tire that is climbing a rock does not work against the forward movement of other three tires. As a result, rather than a lurching motion there is now just a smooth and controlled ascent. And because the same springs are used front and rear, the distribution of articulation between the front and rear axles is perfectly balanced, keeping the body very level and stable when as suspension twists up. Setting the shocks to their stiffest level helps limit potential rollover-causing body sway in off-camber situations, but the soft springs still provide a smooth ride despite the high damping rate.

Recommendation

I could not find a single weakness in the off-road performance of the Canyon State Components YJ Shackle Reversal Kit. It has stood up to all the abuse I have thrown at it and not once was it unable to return its trademark smooth ride on the way home from even the most challenging trails. But should a problem ever arise with the suspension, it is not plagued by the complexity associated with coil spring setups. I applaud Canyon State for achieving their goal of designing a simple, inexpensive, bolt-on suspension kit that provides the kind of performance that until now has been reserved for coil spring suspensions.

Whether starting the buildup of a stock Samurai or upgrading from another setup as I did, building an extreme machine is easy when Canyon State's kit is used as the basis. Future upgrade options are also nearly endless with the customization options for aftermarket Wrangler springs. Priced within the same bracket as other Samurai suspension kits, I think Canyon State's YJ Shackle Reversal kit is irresistible.

--Geoff Beasley