DETROIT -- The wraparound liftgate on the 2015 Lincoln MKC is unlike those on most crossovers. Because the MKC's liftgate has such a complex, curvy shape, it must make a three-stop odyssey before being attached to the vehicle at Ford Motor Co.'s Louisville Assembly Plant in Kentucky.
Lincoln officials say the design required extensive collaboration among its design, engineering and manufacturing arms and supplier Amino North America.
Yes, the liftgate has a function: It gives MKC owners a larger rear opening into which they can place cargo. But the main reason Lincoln designers went to extra lengths to create the liftgate was all about style: They wanted a more beautiful shape.
"This design came about because of the space in the segment we wanted to be," said John Jraiche, MKC chief engineer.
With the MKC, Lincoln is pushing into the fast-growing luxury compact crossover segment, in which the brand has never had an offering.
As Lincoln strives to reinvent itself by luring younger customers, it is looking to set itself apart with distinctive, modern American design. And, though Lincoln officials won't say it, they don't want the MKC to be mistaken for its platform sibling, the Ford Escape.
Hence the stylish -- and complex -- liftgate.
The MKC liftgate gets its start at Amino's small factory in St. Thomas, Ontario. Amino produced many of the sheet metal body parts for two curvy, low-volume General Motors sports cars last decade: the Pontiac Solstice and Saturn Sky.
Amino, a subsidiary of Amino Corp. in Fujinomiya, Japan, specializes in hydroforming to produce parts that are too complex for conventional stamping. Most stamping presses employ male and female dies to stamp parts. Hydroforming dispenses with the female die, using high-pressure water instead.
The MKC liftgate can't be easily stamped in a conventional press. Many liftgates are comparatively flat and rectangular. The Escape's has a more conventional layout with shut lines that split the rear taillights.
The MKC liftgate wraps around to the side of the vehicle, which means it's a more difficult shape to form.
"It's like a 3-D jigsaw puzzle," Jraiche said. The challenge, he said, was to keep the margins uniform around the perimeter. Lasers measured "to make sure we have consistent margins top to bottom and side to side," he said.
Said Amino North America President Trent Maki: "I think that this sort of clamshell, wraparound-type liftgate is probably an industry first. I don't know of any other vehicle that has that type of part."
Sheet hydroforming requires only one die per panel and enables complex shapes to be formed in fewer steps than with traditional stamping.
"This particular part would normally take five to six operations to form," Maki said. "We complete it in just four."
Ford declined to say whether the wraparound liftgate is more expensive to make than a conventionally stamped unit.
Said Maki: "In terms of upfront investment, it's probably lower cost than conventional stamping, but when you talk about part cost, it's a little more because your line speed is slower."
The one-piece wraparound look enables Lincoln to extend its signature taillights across the liftgate and around to the side without interruption by shut lines. The taillights contain 163 LEDs, Jriache said.
Once the part is stamped, it is shipped to a Ford stamping plant in Wayne, Mich., where it is married to a laser-welded inner panel. The two panels are joined with a punch and die process.
The liftgate, which weighs 47 pounds at this point, is then trucked to Louisville for final assembly.
Jraiche said the liftgate created challenges between elements of the Ford and Lincoln organizations.
"There's always creative tensions," he said. "But the teams were ultimately able to "work collaboratively."