Leaf-spring suspensions are like adjustable wrenches. They'll do any job you ask them--but they're rarely ever the perfect tool for the task. Every fullsize pickup has used leaves in the front, and they all still use them in the rear because they give a progressive rate suspension without taking up a lot of space.
Unfortunately, leaf springs don't give the best ride or the most suspension travel because they won't flex enough. If you try to build a set of super-soft springs you run into axlewrap problems. So what's the answer? Two coil springs and a four-link suspension. Or in the case of Skyjacker's newest Super Duty suspension: a set of coilover shocks and a Z-link.
The principle is simple: Separate the half of the suspension that locates the axle under the truck from the half that holds the weight of the truck up. That way you can use a spring that's just stiff enough to support the truck, and use solid steel tubes to locate the axle. The Skyjacker Z-link kit was designed to do just that and replaces the leaf springs on the front of Ford Super Duty trucks to give you a better ride while eliminating any axlewrap. It sounded like a great idea to us so we ordered up the 8-inch-lift version for our Super Duty and headed out to Curt LeDuc's west coast race shop for the install.
The first step for installing...
The first step for installing the 8-inch Z-link suspension (clears 38-inch tires) is to lay out all the parts and read the directions--even if you're a veteran racetruck builder like Curt LeDuc. Familiarizing yourself with the parts and instructions makes your wrenching go smoother and ensures better results.
LeDuc's team tore into our...
LeDuc's team tore into our Super Duty by stripping the old suspension and front axle from the truck. The frame was then cleaned and repainted to give the Skyjacker parts a proper home. We're blessed by having a rust-free California truck, so components like the old pitman arm came off and the new Skyjacker piece went on without any fuss.
The lower Z-link arms mount...
The lower Z-link arms mount to these bolt-on brackets in front of the transmission crossmember. Skyjacker designed these parts to use holes that come in the Ford frame from the factory so you only have to drill a couple of new ones per side. Make sure to use thread lock on all fasteners.
Todd LeDuc took charge of...
Todd LeDuc took charge of installing the lower links into the new brackets on our truck. All four links are nonadjustable so he didn't have to worry about getting them set up to a specific length to locate the axle.
The Skyjacker upper shock...
The Skyjacker upper shock mounts are massive, which they need to be to support the weight of the truck. To help spread that load over the frame, the Skyjacker kit uses a backing plate that gets bolted into the framerail with the shock mount.
The Z-Link suspension is not...
The Z-Link suspension is not like a conventional four-link. With this kit the lower link arms bolt to Skyjacker frame brackets behind the axle, and the upper links pivot from the stock leaf-spring hangers in front of the axle to form the "Z" configuration. To secure all four links to the axle, Skyjacker developed these bolt-on mounts that sandwich the Dana 60.
To cope with the new steering...
To cope with the new steering angles caused by the added lift height, Skyjacker lowers the upper track-bar mount on the frame and raises the axle mount. You could reuse the stock Super Duty track bar with the Z-link kit, but we wouldn't. We highly recommend Skyjacker's optional heavy-duty track-bar upgrade because it's the only thing keeping the axle square in the chassis.
Ride & Drive With the Skyjacker...
Ride & Drive
With the Skyjacker Z-link installed, our F-250 definitely rode better than it ever did with leaf springs. And there's very little vehicle roll even without the front sway bar installed. The Z-link kit gives the truck a better approach angle, but it does lose ground clearance at the lower arms when compared to the leaf springs.
To dial our truck in, we need to adjust the ride height to get more suspension travel up front. Right now the shocks bottom easily as there is only 3 1/2 inches of uptravel. It would be nice if Skyjacker offered a remote-reservoir shock that would give the suspension more travel with the same overall shock length.
35-Spline Upgrade Want stronger...
35-Spline Upgrade
Want stronger 35-spline stub shafts for your Super Duty? Off Road Unlimited has developed a conversion kit that gives you 1 1/2-inch-diameter outers and a set of modified unit-bearing hubs to replace the stock 30-spline stuff. This kit works with the common Warn 35-spline locking hubs and is an easy bolt-on. By the time you read this, ORU should also have a live spindle conversion that will convert your Super Duty to conventional spindles and 35-spline outers.
Race-Bred Heritage
The inspiration for Skyjacker's Z-link suspension comes from its involvement with off-road racers like Curt LeDuc. To learn all the ins and outs of the new coilover conversion, we spent a few days at Curt LeDuc's raceshop while his team installed the Z-link on our Super Duty. Thanks again, guys! While we were there we checked out LeDuc's Class 8 Ford that was in the shop getting prepped for the Vegas to Reno race. Note the custom-length Skyjacker coilover and bypass shocks.