Click for Coverage
  • JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler
Subscribe to the Free
Newsletter

WFO Concepts SAS For Chevy Duramax 2500

Posted in How To: Transmission Drivetrain on June 5, 2017
Share this

Brent and Amber Rederick have owned a number of 4WD rigs and each has been built to tackle Southwestern trails and get them off the beaten path for remote camping. When they found they no longer needed their ’04 Chevy 2500 Duramax diesel pickup for tow duty, they set out to convert it for backcountry duty as well. They knew they wanted a more robust front suspension and axle setup, so a straight-axle swap seemed obvious.

The Rederick’s decided on gaining 3 inches of lift height using a conversion kit from WFO Concepts. The setup uses a radius-arm link suspension. It’s designed to work with ’01-’10 Duramax trucks using an ’05-’12 Ford Super Duty Dana 60 front axle from an F-250 or F-350 model.

The kit comes complete with suspension links, frame plates and mounts, shock mounts, transmission crossmember, steering components, bumpstops, brake lines, and ABS sensor wiring. The 3-inch kit is designed to be used with 8-inch-travel coilovers to accommodate 35-inch tires. WFO’s 6-inch kit with 10-inch-travel coilovers is designed to allow running 37-inch tires.

Once the donor front axle was ready to go, the couple successfully performed the swap in their driveway over the span of several days. The stock IFS components and mounts were all removed and the WFO swap kit installed. Cutting and welding was required to get all the new mounts in place. Once complete, the truck got a fresh set of wheels and 35-inch rubber. It now has a bolder stance, much better ride quality than stock, improved articulation, and greater front axle reliability.

Here is the 3-inch swap kit with all link components, frame plates, crossmember, shock mounts, and King coilovers with remote reservoirs. The steering components are not shown here.
The Redericks started with a Dana 60 axle from a ’10 Ford F-250 Super Duty. It was fully checked and resealed, and new ball joints and U-joints were installed. They used the stock 4.10:1 gearing in the front axle and regeared the factory rear axle to match.
Here you can see the WFO coilover mounts added to the top of the donor axle. The mounts bolt onto where the old coil buckets were and then are welded in place.
On the 3-inch kit the factory track bar mount can be retained. However, for this swap, the beefier mount from the WFO 6-inch kit was welded in place of the stock bracket.
The rest of the axle was assembled with new unit bearings. Custom machined hubs were used to allow retention of the Chevy 8 on 6.5-inch lug pattern with the Ford unit bearing wheel hubs. New brake calipers, pads, and Warn Premium manual locking hubs were installed. Here, you can also see the factory link mounts on the Ford axle.
New tie-rod ends were installed and the upper one shown here on the passenger-side knuckle connects to the new WFO dropped drag link.
The included transmission crossmember is designed to work with the common Allison automatic transmission. However, this truck has the less-common ZF six-speed manual transmission. Brent cut down the provided mount and fabricated a new mounting plate to bolt to the ZF unit.
The lower link mounts attach to the framerails with a series of bolts. The mounts use some factory frame holes for alignment and then others are drilled for the additional bolts. The center crossmember bolts to the two lower link mounts.
Soon it was time to pull out the plasma cutter and start melting metal. After removing the A-arms and axle components, Brent cut off the two IFS crossmembers and made way to drop the IFS differential assembly out of the truck.
The stock steering box is retained but uses a new pitman arm, which is supported in double-shear configuration using a bearing pillow block supported between the framerails.
All the remaining IFS mounts were cut from the framerails along with the old shock mounts. Then the surfaces were ground and cleaned to prep for new welds. Brent used aircraft paint remover to rid the frame of some of the factory coating.
The 3/16-inch-thick frame stiffener plates were clamped in place and tack welded. They were then fully welded over a period of several hours, alternating weld locations around the circumference to prevent warpage.
The new shock towers were located using index marks on the frame plates and welded to the frame. You can also see the new frame-side track bar mount on the framerail.
The lower links are constructed from 2-inch, 0.250-inch-wall DOM tubing while the upper links are built from 1.75-inch, 0.250-inch-wall DOM tubing. WFO provides threaded inserts to be welded on once link length is determined. Duroflex joints are used on the lower links.
Here you can see the geometry of the radius arm suspension. Each upper link attaches to a lower link with a 7/8-inch by 3/4-inch rod end bolted to a mount on the lower link.
Brent rotated the axlehousing to achieve about 6 degrees of caster. Once set, he tack welded each upper link mount to its lower link to set the radius arm geometry.
WFO provides long stainless-braid brake hoses for the swap. The factory Ford ABS sensors are retained and are compatible with the Chevy ABS system. Only the wiring needs to be adapted between the axle and vehicle harness.
The links were removed from the truck and the upper link mount fully welded to the lower link. Once painted, the links were finally bolted in place. Some link adjustment is still possible with the threaded ends, if needed.
With the links fully installed, the axle was cycled upward so bumpstops could be located on the frame and welded in place. Here you can also see the completed installation of the track bar in the axle mount and the WFO dropped drag link.
King coilovers specifically valved for this application were installed in the new shock mounts. The shocks are 8-inch-travel coilovers and have remote reservoirs that mount to supplied brackets that bolt to the top of each shock tower.
The final piece of the conversion was hooking up the driveshaft. The factory ’shaft is retained and only requires installation of a provided conversion U-joint to mate to the new front axle.
The finished truck in action.

What’s The Cost?

The overall cost of a conversion like this can vary greatly. A big variable is the acquisition cost of the front axle and how you decide to build it. Upgrading components can drive up the cost, as can regearing or adding a limited-slip or locking differential. Here are approximate dollar figures to give you an idea of the parts cost:

Dana 60 donor axle: $1,000 to $2,500
WFO Concepts SAS kit: $2,550 to $2,690
King coilover shocks: $1,180 to $1,400
WFO steering brace kit: $180

You’ll also need to allow for cutting, grinding and welding material plus items such as paint, cleaners, and fluids. With the axle completed and ready for use, the kit installation took about three full days of work. Some steps may go faster or slower depending on tools you have available and your level of mechanical expertise.

Sources

WFO Concepts
Auburn, CA 95602
530-268-9494
http://www.wfoconcepts.com

What's Trending

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Browse Articles By Vehicle

See Results