Suspension technology has come a long way in the past four decades. Leaf springs are now a thing of the past on everything but the rear of pickup trucks. While there’s no denying that coil springs and independent suspension offer a smooth ride and generous wheel travel, there’s an inherent beauty in the simplicity of leaf springs. This one component not only suspends the axles but also locates the axle fore and aft and side-to-side and provides sway control.
Skyjacker makes coilover conversions for modern Jeep Wranglers with beefy control arms and high-angle rod ends, but we went back in the company’s catalog to source a set of Softride leaf springs and M95 monotube shocks for our 1970 Land Cruiser. These parts are inexpensive and easy to install. They improved the ride quality of our FJ40 while providing enough room for 33-inch Toyo Open Country M/T tires.
Skyjacker’s 2 1/2-inch lift springs are mild enough that they don’t require longer brake lines, a dropped drag link, or axle shims to adjust pinion angle. This further simplifies the installation and keeps costs down, leaving room in the budget for options like U-bolt skidplates and new shackles, which we sourced from the Land Cruiser specialists at Man-A-Fre. We were able to install the suspension in a weekend with simple handtools, just like guys used to do back when Lonnie McCurry started Skyjacker in 1974.
In stock form the FJ40 was rugged, right down to the suspension. We wanted to improve the ride quality while making room for larger tires. We also wanted to install the components ourselves and didn’t want to go broke in the process. This was a tall order, by Skyjacker had exactly what we needed.
There is beauty in simplicity. Skyjacker’s complete kit includes four new leaf springs, polyurethane bushings, and shocks. Four different shock options are available to fit your budget and specific use. The steering stabilizer is optional; we will install it in the future when we upgrade our steering.
We value American-made products, even if we are installing them on a Japanese 4x4. Skyjacker makes its leaf springs right here in the USA, supporting hardworking Americans and providing improved quality control measures compared to offshore manufacturing.
The stock springs could support a lot of weight, but with the top removed and the FJ40 empty it rode like a dump truck. Note that we soaked all of the bolts ahead of time to ease disassembly. Our California truck is surprisingly rust-free, but if you live in the Rust Belt you might need a torch or a reciprocating saw to remove the old U-bolts.
In order to keep the individual leaves in a spring pack from fanning out during droop, clamps are used. Budget springs use clamps that simply wrap around the springs, hindering their movement. Skyjacker’s Softride springs use bolted clamps that allow each leaf to move freely.
While leaf springs have been around for centuries, a lot of technology is packed into their design. Skyjacker’s Softride springs use tapered leaves with Teflon sliders between them to reduce friction and provide a smoother ride on the street and trail.
We started by supporting the Land Cruiser by the frame with tall jackstands. This allowed us to remove the wheels and access the axles to swap the leaf springs and shocks. In the rear, the jackstands went in front of the spring mount, making the springs easy to reach. In the front we supported the vehicle by the bumper, which made installation slightly more complicated.
We started by disconnecting the drivelines, shocks, and brake lines and then unbolted the shackles to rotate the axle down onto the ground. At that point we unbolted the fixed end of the spring and then finally removed the U-bolts from the axle. In retrospect it would have been easier to put jackstands under the axle and just swap the leaf springs one at a time.
Skyjacker includes new U-bolts with its suspension, but the configuration of the FJ40 has the vulnerable U-bolts pointing down towards the ground. We trimmed them to length and protected them with these Warrior U-bolt skidplates from Man-A-Fre.
Shackles are an often overlooked part of a leaf spring suspension. They have to accommodate the spring length changes that occur as the suspension cycles. We used stock-length shackles from Man-A-Fre to prevent any changes in pinion angle or caster. They have greasable pins that allow them to move smoothly and improve ride quality.
The rear suspension retains all of the factory geometry with the exception of the lower shock mounts, which are moved to the U-bolt skidplates. By lowering the shock mount, additional travel is gained while the shocks are kept mounted under the tub of the Land Cruiser.
Skyjacker offers a variety of shocks with its lift kits, from the economical Hydro 7000 up to the top-of-the-line M95 monotube shocks. We choose the nitrogen-charged M95 shocks for their application-specific valving and resistance to fading even when subjected to continuous use over rough terrain.
The mild lift height meant that no changes were necessary to the factory brake lines or steering system, even with the funky Toyota push-pull configuration (which we intend to replace with Saginaw steering soon). Skyjacker includes polyurethane bushings with the leaf springs, and the greasable bolts of the Man-A-Fre shackles keep squeaking to a minimum.
We had the factory wheels powdercoated in the original gray color by Marq Powder Coating. The color code is Cardinal GR21, and we think they look just about perfect on our old Land Cruiser.
We have run Toyo Open Country M/Ts on a variety of vehicles, and they are one of the quietest mud-terrains on the market, always requiring very little weight to balance. Our 33s are Load Range C, which is perfect for our small 4x4, but Toyo offers load ranges up to F in a variety of sizes to accommodate everything from Jeeps to 1-ton diesel tow rigs.
Toyo is one of the only companies to make a 33-inch-tall tire for a 15-inch rim in a 10 1/2-inch section width. These 33x10.50R15 pizza cutters are a perfect fit on our stock wheels, and the narrower tires weigh less and are easier to fit under the uncut fenders on the Land Cruiser.
We capped off the Skyjacker lift and 33-inch Toyo tires with a set of OEM hubcaps sourced from Man-A-Fre. The hubcaps really complete the vintage look that we are going for with our old Land Cruiser. Next we plan to upgrade the steering to turn the 33-inch Toyos.