2003 Ford Expedition
1. The 2003 Ford Expedition is the second generation. The first was introduced as a ’97 model.
2. Chassis is 70% stiffer in torsion than previous model. There’s a 67% improvement in bending stiffness. Fully boxed frame: hydroformed components. The frame sections are approximately 10 ft. long and run from just in front of the rear suspension to the front wheels. Frame wall thicknesses range from 2- to 4.7-mm thick. Front and rear pieces are fully boxed, welded with C-channel steel. Permit replacement in case of crash damage. Rear frame sections have vertical oval shapes cut into them—portholes—for the travel of the axles. The portholes are reinforced with steel tubing. There’s 9-in. of wheel travel. Laser-cut, through-welded cross-members employed. Cross members are welded at both inner and outer faces of frame rails; said to be more resistant to bending and more durable over the life of the vehicle than bolting, riveting, or welding on one side. The frame is electrocoated.
3. Body torsional stiffness up 42%. Big contributing factor: What’s said to be the industry’s “most extensive use” of structural foam. Application areas include the joints at the top of the B-pillars, top and bottom of the D-pillars, and in underbody channels. Engineers had considered using steel braces to bolster stiffness. The foam proved to be less complex and lighter. Additionally, it reduced interior noise by 2 db.
4. Bumpers are replaced by fascias. Allow a better fit in the assembly plant. The structural bumper beam beneath the fascia is set to the height of a car.
5. Four wheel independent suspension. First independent rear suspension on a full-size SUV. Reduces rear unsprung mass by 110 lb. as compared to previous five-link axle.
6. New braking system with largest rotors in segment: 13 in. front; 13.5 in. rear. (Interestingly, Continental Teves is complete brake system integrator and supplier, managing and delivering the calipers, rotors, booster, master cylinder, adjustable pedals, four-wheel ABS, Brake Assist, Electronic Brake Force Distribution, and optional traction control and AdvanceTrac.)
7. AdvanceTrac: monitors all four wheels. Factors taken into account: driver intent, road surface conditions, and wheel slip. Delivers torque where needed by using electronic braking, thereby helping control skids or spins. Complemented by ControlTrac four-wheel-drive system: its transfer case divides torque front-to-rear.
8. Tire pressure sensors are integrated with the valve stems. Over- and under-inflation conditions are regularly monitored. Any detected problems cause an alert on the message center and an audible tone.
9. 5.4-liter Triton V8 has a new cast-iron block designed to reduce vibration: ribbing and bracing are designed in; there are thicker side skirts and reinforcements at the oil pan flange. The oil pan is a metal-plastic-metal composite. The cylinder heads, timing chain covers, and intake runners are aluminum. The pistons are a hypereutectic cast aluminum alloy; piston skirts are coated with a Teflon-based material. Valve covers are composite.
10. Driveshaft is a seamless tube. Yokes are connected at each end with friction welding.
11. Handles up to nine passengers. Total payload capacity: 1,615 lb.
12. Second-row bench’s (40/20/40) sliding center section can move forward 11 in. The optional power-fold option folds the third row flat with the push of a button.
13. New variable-assist power rack-and-pinion steering gear instead of recirculating-ball system previously used. It is twice as stiff. Steering system components are 22 lb. lighter than previous model’s.
14. Differential cover is structurally ribbed cast aluminum with a machined gasket surface. It effectively serves as a bridge between the differential housing (there’s a 9.75-in. ring gear within) and two mounting points to the frame cross member.
15. Some rear control arm bushings have oblong-shaped holes cast into them to accommodate wheel movement in the case of sharp jolts. Other bushings include molded-in metal reinforcements to remain firm to accommodate steering forces.
16. Six of the eight control arms are cast aluminum. The front upper control arms are forged steel. The aluminum control arms are lightweight compared to steel, but they are comparatively thick. The thin cross-section of the steel control arms permits packaging the coil-over-shock system used in two- and four-wheel-drive configurations.
17. Transfer case is magnesium rather than aluminum—which saves 11 lb.
18. Overall: 623 lb. of aluminum and 35 lb. of magnesium are used.
19. Overall dimensions: length: 205.8 in.; width: 78.7 in.; height: 77.6 in.; wheelbase: 119 in.; ground clearance: 8.9 in.; base curb weight: from 5,267 to 5,686 lb.
20. Built at the Michigan Truck Plant, where Ford first installed its end-of-line vibration analysis system. It uses a three-axis micro-accelerometer that is attached to the vehicle roof. The system monitors vibration during engine start as well as during the roller testing. Determines whether there are anomalous patterns that indicate problems ranging from wheel imbalance to a misaligned driveshaft.