F-Series to Follow SUV Hydroforming Lead

Add Ford Motor Co.'s next-generation F-Series pickup to the growing list of vehicles that employ hydroforming in their designs, says Chris Theodore, vice president-North America product development.

The pickup — America's best-selling truck for 25 years — will follow the lead set by '03 Ford Expedition and Lincoln Navigator, Theodore tells Ward's. Prototype pickups were recently inspected.

When F-Series debuts next year, coinciding with the auto maker's 100th anniversary, its design also might make use of structural foam. But Theodore neither confirms nor denies, saying, instead, that the difference between the current F-Series and its successor will be as dramatic as the changes made to Expedition and Navigator, “only more so.”

The redesigned SUVs share the PN96 platform and are built at Ford's truck assembly plant in Wayne, MI. They feature extensive use of hydroforming, which is credited with improving frame stiffness by 70% — without adding weight.

Such benefits are well-known to General Motors Corp., which uses hydroformed frame components in its fullsize pickups and midsize SUVs. The Chrysler Group's Dodge Ram 2500 and 3500 also employ hydroformed frames.

Dana Corp. produces the Ford frames and has designed a unique hydroforming press, RoboClamp, to produce lengthy side rails and eliminate the need for multiple stampings (see WAW — Jan. '00, p.83). Dana's plant in Elizabethtown, KY, is preparing four RoboClamp presses to handle the Ford frame volume.

The entire frame of PN96, save the rear third, is hydroformed. The rear section is cut-and-weld because its complex geometry isn't conducive to hydroforming.

Having seen Ford Explorer and Mercury Mountaineer benefit from independent rear suspension, Ford is employing the same architecture to improve the fullsize SUVs. The inclusion of IRS, coupled with challenges such as packaging a fullsize spare, dictated the switch to cut-and-weld. “We couldn't get hydroforming to work,” says a program insider.

But F-Series could see a greater percentage of its frame employ hydroforming than PN96 because an IRS is less compatible with pickup applications than solid axle suspensions, another source says.