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Solving Super Duty Axle Problems

Posted in How To on January 26, 2004
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When lift kits and larger tires are installed on Ford Super Duty or Excursion trucks, it's quite common for several gremlins to rear their ugly heads. The most common problems are bumpsteer from tweaked steering components and rapid wheel-bearing failure due to the forces exerted on the OEM unit bearings by the larger tires and positive offset of aftermarket wheels. We probably don't have to tell this to you readers who own lifted Super Dutys because you might already be living it. If so, that's bad, because for reasons of safety, no steering quirk is acceptable. Also, new unit bearings can wreck your wallet to the tune of $400 or more per side.

What you may not know is that the folks at Dynatrac recently introduced a kit that addresses and solves these problems. It's called the Super Duty Combo Kit, and it includes the parts to upgrade three major areas. First, it replaces the stock steering with a complete crossover steering system to improve handling and increase ground clearance. Second, it replaces the expensive and weak factory front sealed unit bearings with new knuckles and hubs in a fixed-spindle design. And third, it upgrades the outer axleshafts from the stock 30-spline units to stronger 35-spline units.

We recently had the opportunity to observe the complete installation of this kit at Attitude Performance in Elk Grove Village, Illinois, where owner Matt Dinelli installed the kit on a Super Duty with 12 inches of lift. Install time was a little more than 7 hours--well within the 5-10 hours that Dynatrac says is the normal time for the kit install.

We found the kit's comprehensiveness and outstanding quality to be quite impressive. Not only do the folks at Dynatrac package the kit with every component needed to solve these durability and handling issues, but the Dynatrac parts are significantly beefier than the factory components. In fact, their beefiness borders on overkill. In our book, that's a very, very good thing.

The following photos chronicle the major parts installations of the Super Duty Combo Kit, beginning with the assembly of the new Dynatrac Pro 60 knuckles. Due to space limitations we've omitted illustrating the disassembly of the wheels, calipers, rotors, ABS sensors and cables, hubs, unit bearings, axleshaft assemblies, tie rod, drag link, steering stabilizers and knuckles. Removal of these items is covered in detail in the Super Duty Combo Kit installation guide.

Results? Shortly into our testdrive we noticed a substantial improvement in steering when compared to the well-made custom system that had been on the truck. Bumpsteer was virtually nonexistent, and this made the truck more predictable. The crossover steering offered a vast improvement in ground clearance when compared to a standard steering system, and the dual steering stabilizers eliminated all shake as the big 44-inch tires rolled along. Clearly, time will be the judge of bearing life, but we have no reason to doubt that with regular maintenance, the packable fixed-spindle design will perform admirably over the life of the truck. Here are some of the highlights of this kit's installation.

PhotosView Slideshow

Kit FAQs
The Super Duty Combo Kit is designed to be compatible with most commercially available 5- to 14-inch lift kits. It is not designed for stock suspensions through 4 inches of lift (a new kit for this application will be debuting soon). You may fit tires up to 44 inches in height and 18.5 inches in width, but 18.5-inch tires on 12-inch or narrower wheels may cause the tire to rub against the steering drag link. Spring-pad thickness may not exceed 4 inches, and angled shims between the spring pack and axle will cause a critical reduction of clearance between the drag link provided with the kit and the top of the righthand spring pack. You will also need to use a stock pitman arm, as a dropped pitman arm will cause bumpsteer. Some of the less common tools and supplies needed for installation include a 4- or 6-point spanner socket, heavy-duty pitman-arm puller, torque wrench and antiseize compound.

Kit contents
The Super Duty Combo Kit list of components reads like a dream come true for the Super Duty owner wishing to seriously improve his/her truck's handling and durability. Following is the tally of what you can expect when you open the box.

* Pair of Pro 60 steering knuckles with new ball joints installed * Pair of Pro 60 spindles (heavy-duty fixed-spindle design) * Pair of Pro 60 8-on-170mm wheel hubs (fixed-spindle design) * Pair of Pro 60 35-spline locking hubs (stock are 30-spline) * Pair of Warn Premium 35-spline locking hubs * Full set of customer-serviceable wheel bearings, races and seals * New adjustable track bar with urethane bushings * Complete crossover steering package that includes a billet righthand steering arm, tie rod assembly (11/2-inch diameter x 3/8-inch wall) including greasable rod ends and drag link assembly (11/4-inch diameter x 5/16-inch wall) including greasable rod end * New, custom dual-opposed steering stabilizer kit including shocks * All mounting hardware, brackets and instructions


Huntington Beach, CA 92647
Attitude Performance
Arlington Heights, IL

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