2007 Chevrolet Silverado and GMC Sierra Revealed

Press Release

Page 1 – Overview
Page 2 – Chassis
Page 3 – Design
Page 4 – Interior
Page 5 – Safety
Page 6 – Heritage

Chassis and Suspensions

Provide Smooth, Responsive Handling on 2007 Silverado and Sierra

• New, fully boxed frames that are stronger and stiffer

• Wider front and rear tracks enable smoother, more stable ride and handling

• New coil-over-shock front suspension for superior ride control

• New rack-and-pinion steering delivers responsive, linear, on-center feel

• Segment-first standard StabiliTrak electronic stability control system with rollover mitigation technology

• Class-leading capability, including segment-best 10,500-pound (4,763 kg) towing capacity

• Maximum payload capacity of 2,160 pounds (980 kg)

Comprehensively redesigned chassis and suspension systems on the new, 2007 Chevy Silverado and GMC Sierra are the backbone of a refined, responsive driving experience – establishing a new benchmark for the segment. The agile ride and handling delivers a heightened feeling of control while supporting class-leading capability, including the segment’s best towing capacity, 10,500 pounds (4,763 kg).

An all-new chassis, with wider front and rear tracks and new coil-over-shock front suspension, is supported by five distinct suspension packages that provide ride and handling characteristics tuned for specific performance requirements. These components deliver an exceptionally smooth ride, enhanced quietness and an overall feeling of strength and stability.

“The strength of the new chassis supports refinement and control unlike other full-size trucks – these pickups have a solid, confidence-inspiring feel,� said Terry Woychowski, vehicle chief engineer for full-size trucks. “The combination of a stronger, more robust chassis and new suspension and steering systems gives the trucks a nimble, precise and smooth driving experience.�

Features of the new chassis and suspension systems include:

• A new, fully boxed frame that is significantly stronger and stiffer, with hydroformed front section and high-strength steel reinforcements throughout

• Wider front and rear tracks – approximately 3 inches (76.2 mm) in front and 1 inch (25.4 mm) in rear – enable increased stability, as well as a smoother, more controlled ride

• New coil-over-shock front suspension delivers linear, responsive ride and handling characteristics

• New rack-and-pinion steering system delivers precise, responsive steering with enhanced on-center feel

• Hotchkiss-type rear suspension with splayed shock absorbers – angled outward and upright – enhances ride feel

• Standard StabiliTrak electronic stability control (crew cab models)

• Large-capacity brake system with robust apply system and standard next-generation Bosch ABS provides shorter stopping distances, better pedal feel and quicker brake response

• Range of 17-, 18- and 20-inch wheels with tailored body-to-wheel relationship

Fully boxed frame

The 2007 Chevy Silverado and GMC Sierra feature a fully boxed frame, the foundation on which the chassis, suspension, powertrain and body systems are mounted. It offers more strength and stiffness – 234 percent increased torsional stiffness, 136 percent increased lateral stiffness and 62 percent increased vertical bending stiffness – which enables the vehicles’ responsive driving experience and supports their class-leading capability. There are three distinct frame sections, or “bays,� each with specific strength and support characteristics.

The new, boxed frame has a variable-height design and uses high-strength steel in targeted, critical areas to improve strength and bolster crashworthiness. Overall strength and increased stiffness are combined with more precise, integrated mounting brackets for powertrain, suspension and axle components, enabling engineers to tune chassis and suspension bushings, springs and other elastomeric components for more accurate and refined ride and handling characteristics. The result is smoothness and responsiveness, with the capability expected of a full-size pickup.

Front bay: The front frame bay is comprised of hydroformed side rails and includes the radiator support cross member, engine support cross member and front lower control arm cross member – extending from the front impact beam to approximately the A-pillar area. GM pioneered the use of hydroformed frame rails for full-size trucks on the previous-generation vehicles. The process uses highly pressurized fluid – up to 20,000 psi – to shape the frame rails. The revised design of the 2007 truck front bay section is approximately 90 percent torsionally stiffer than the previous generation, without a significant difference in mass.

A new powertrain mounting system is part of the front bay section. It is welded to the engine cross member and includes very stiff mounting brackets for the engine and transmission. The brackets house unique elastomeric bushings (on vehicles not equipped with Active Fuel Management) to dampen vibrations. Trucks equipped with Active Fuel Management use hydraulic mounts to accommodate the changing rotational forces associated with the cylinder-deactivating technology.

A new, four-point front axle mounting system is integrated with the front bay and uses stronger axle mounting brackets. These brackets, combined with the front bay’s superior stiffness, offer greatly reduced driveline vibration. Also, the front bay incorporates new, segment-exclusive compatibility brackets, which provide better interaction with vehicles of all sizes during a crash.

Mid bay: The new, boxed side rails of the middle bay support two stiffness-enhancing cross members. Strength also is built into joining of the front bay to the middle bay, with the front bay’s hydroformed rails slipping inside the boxed sections of the middle bay by a full 9.4 inches (240 mm).

The side rails of the middle bay section are constructed of two pieces of high-strength steel that are welded to form the sturdy box design. The rails also have a variable-height construction that enables strategic placement of strength-enhancing materials in certain areas for a more integrated, lower-mass design.

Rear bay: The rear bay boxed rail sections are joined to the middle bay with an overlapping, shingle-type construction. The rear bay section offers enhanced strength via four cross members, including a more robust fuel tank cross member and a stronger, single-piece spare tire cross member.

Wider front and rear tracks

The 2007 trucks have wider front and rear tracks than previous-generation models. The front track is 3.2 inches wider (81 mm) and the rear track is 1 inch (25 mm) wider. A wider track promotes overall vehicle stability, which the driver and passenger can feel through the vehicle’s secure ride and handling attributes, as well as flatter, more controlled cornering. The wider track widths also enhance smoothness.

Coil-over-shock front suspension

A new coil-over-shock front suspension is used on all light-duty models, along with a new, robust mounting system. The coil-over-shock configuration offers smoother, more precise and nimbler ride and handling characteristics, especially with the larger wheel-and-tire combinations offered on the new Silverado and Sierra. Vibration and harshness also are greatly reduced when compared to the previous-generation torsion bar front suspension design.

The new suspension system uses tuned coil springs and monotube shock absorbers, along with steel upper control arms and cast iron lower control arms. Specific tuning for each suspension package – Z83, Z85, Z60, Z71 and NHT – provides optimized ride characteristics.

“Each suspension is tuned to deliver a level of control that balances the trucks’ capabilities with a precise driving feel,� said Doug Stroud, vehicle dynamics engineer. “Shock tuning, stabilizer bar size and numerous other factors are tuned specifically to suit the performance desired by the customer.�

Complementing the coil-over suspension design are new, stiffer frame attachments for the suspension components and a new, four-point front axle mounting system. These stiff, accurate mounting points – including softer bushings located within brackets of the stiff front bay frame section – contribute to the vehicles’ more controlled and linear driving feel.

Rear suspension

A Hotchkiss-type live axle rear suspension is used for all Silverado and Sierra models. The rear suspension features a more robust rear axle design that offers increased payload weight. A new, splayed arrangement of the rear axle shock absorbers enhances the ride quality. The splayed shocks are angled outward and more upright, which helps provide more linear and stable responses to motion.

“The rear shock orientation allows the suspension to make the most effective use of the shocks,� said Stroud.

Like the front suspension, the rear suspension uses new, stiffer mounts for suspension component attachment, along with variable-rate springs and monotube shocks (Z83 suspension package uses twin-tube rear shocks). The accuracy and responsiveness of the springs and tuned shocks provide superior dampening and ride control, regardless of whether the vehicle is carrying a payload or pulling a heavy trailer.

Suspension choices

The 2007 Silverado and Sierra are available with five suspension systems, each tuned to provide an optimized ride with smoothness, a greater feeling of isolation from the road and minimal body movement.

“More than any previous models, the new Silverado and Sierra suspension systems deliver distinct performance, ride and handling traits,� said Stroud. “Each was designed for specific tasks, giving customers the choice to select the suspension system that best fits their needs.�

Here is a look at the Silverado and Sierra’s available suspension systems:

Z83 – The solid, smooth ride suspension provides a comfortable ride, with 46-mm front monotube shocks, 35-mm twin-tube rear shocks and specific stabilizer bars.

Z85 – Designed for enhanced handling and trailer towing. It includes 46-mm monotube front and rear shock absorbers and specific stabilizer bars.

Z71 – Available on both 2WD and 4WD Silverado and Sierra models (except Sierra Denali). This suspension system includes 46-mm front and rear monotube shocks, specific stabilizer bars, off-road jounce bumpers, skid plates, on/off-road tires, heavy-duty limited-slip rear differential and a heavy-duty air cleaner.

Z60 – Designed for maximum street performance and offered with 20-inch wheels. It includes 46-mm front and rear monotube shocks and specific stabilizer bars.

NHT – The maximum capacity trailering package; it incorporates the Z85 suspension with a 9.5-inch axle, 17-inch wheels and more.

Rack-and-pinion steering system

The 2007 Silverado and Sierra pickups have a new, hydraulic power-assisted rack-and-pinion steering system. It delivers an optimized on-center steering feel and more immediate, precise steering responses.

The new system mounts on the engine cross member of the front bay frame section, directly beneath the engine. This mounting position uses the inherent stiffness of the frame to enhance the direct and linear feel of the steering system, reducing the driver’s need for continuous corrections during turns and sweeping corners. On 4WD vehicles, the steering rack is located forward of the front differential.

Low-friction, highly precise ball-and-needle bearings within the steering system contribute to the precise and immediate feel from the steering wheel. The system also is engineered with low-noise valve technology that helps reduce noise and vibration.

Large-capacity brake system

A high capacity brake system with a new, four-channel ABS system provides GM trucks with superior stopping capability. ABS is standard on all models. The headlining elements of the new brake system include large-diameter front and rear disc rotors (when equipped with four-wheel disc brakes) and new, stiffer brake calipers.

The front rotors are thick, with large cooling vents, and are acted upon with stiff, cast iron, dual-piston brake calipers. The calipers reduce the tendency for flexing during hard or prolonged braking and, with the large rotors, contribute to a more direct and stronger brake pedal feel.

Rear drum brakes are used on models with a Gross Vehicle Weight Rating (GVWR) of under 7,000 pounds. Four-wheel disc brakes are used on vehicles with a GVWR of 7,000 pounds or more and trucks equipped with the 6.0L V-8 and StabiliTrak. The rear disc brakes feature standard vented discs and a single-piston rear brake caliper design that contributes to reduced brake noise and more immediate braking response.

The brakes are complemented by a more robust brake application system, including a larger master cylinder and active brake booster. Engineers tuned the application system to optimize pedal feel and system responsiveness. Less pedal pressure is required to provide a more immediate brake response.

A next-generation Bosch 8.0 ABS system is standard on all 2007 Silverado and Sierra models. It has more precise valve control that requires less cycling of fluid from the brake master cylinder, resulting in reduced noise and enhanced feel when ABS is activated during braking. The new ABS system also is less complex and has reduced mass when compared with the previous system.

The ABS system is linked to the StabiliTrak electronic stability control system to help mitigate the occurrence of rollover events.

StabiliTrak electronic stability control

In a first for the segment, GM’s sophisticated StabiliTrak electronic stability control system is standard on crew cab models and available on extended cab models. Partnered with the new brake system and four-channel electronic brake controls, the system provides more precise, controlled ABS stops, as well as enhanced traction/yaw stability.

The StabiliTrak system has rollover mitigation technology. Rollover mitigation adds software algorithms that use StabiliTrak sensors to proactively anticipate vehicle “tip up� on a flat road surface, and rapidly applies brake pressure to reduce lateral force in the vehicle. This brake force intervention can help reduce the likelihood of a rollover in certain circumstances – including “fish hook� maneuvers that involve sudden and rapid back-and-forth steering.

On 4WD models, StabiliTrak uses brake control and engine torque management to precisely manage the speed of each wheel as well as torque across the front and rear axles. On 2WD models, the system precisely controls the speed at each wheel and manages side-to-side torque on the rear differential. Individual speed sensors at each wheel provide signals to the control module, enabling it to aggressively adjust brake pressure. However, traction is controlled by transferring torque across the rear axle – rather than front and rear axles, as in 4WD models. When the vehicle is on a slippery surface, the traction system increases torque to the rear wheel that has the most traction.

On 2WD and 4WD models, the vehicle brake system provides torque-biasing to enhance traction and engine management as required to assist in controlling traction and yaw stability. The Autotrac transfer case’s control algorithm has been integrated with the StabiliTrak and ABS systems to provide enhanced vehicle stability by managing the front-to-rear torque distribution.

StabiliTrak is always on and fully functional. It is automatically enabled, providing full stability, traction and ABS control, whenever the vehicle operates in forward gears. The system intervenes when it senses one or more of the wheels slipping or when the vehicle is not following the driver’s intended path. It detects slippage during braking or acceleration and automatically adjusts individual wheel brake pressure, engine torque and, on 4WD Autotrac models, adjusts front to rear drive torque distribution, as required, to achieve optimal control.

Rear axles

A robust 8.6-inch rear axle is standard on most Silverado and Sierra models and is available with a range of axle ratios between 3.23:1 and 4.10:1, giving customers several choices to optimize fuel economy and towing capacity to fit their needs. The exclusive Eaton G80 automatic locking differential is available. Most competitors offer only open or limited-slip differentials.

Vehicles equipped with the VortecMAX 6.0L V-8 have a standard, heavy-duty 9.5-inch rear axle.

Wheels and tires

Complementing the tuned suspensions of the 2007 Silverado and Sierra is a range of wheel and tire sizes, including standard 17-inch wheels and available 18-inch and 20-inch wheels. Sierra Denali comes standard with 18-inch wheels and 20-inch wheels are optional.

Maximum capacity trailering package

An exclusive feature on Silverado and Sierra light-duty pickups is the availability of a maximum capacity trailering package, which offers the high-output, VortecMAX 6.0L V-8, heavy-duty 9.5-inch rear axle and other enhanced components, enabling Silverado and Sierra to have the segment-leading maximum towing capacity of 10,500 pounds (4,763 kg). The package is available on crew cab and extended cab with standard box, 2WD and 4WD models (except Sierra Denali). Details include:

• VortecMAX 6.0L V-8 with aluminum block, variable valve timing and Active Fuel Management, rated at 367 hp (274 kW) and 375 lb.-ft. of torque (508 Nm)*

• Hydra-Matic 4L70 four-speed automatic transmission

• Z85 suspension

• Four-wheel disc brakes

• StabiliTrak

• Seventeen-inch aluminum wheels and on/off-road tires

• Heavy-duty 9.5-inch rear axle with 3.73 (2WD) or 4.10 (4WD) axle ratios

• Increased-capacity rear springs

• Specific steering gear

• Larger engine cooling fan

• Front bumper with cooling inlets

*SAE certified. A new voluntary power and torque certification procedure developed by the SAE Engine Test Code committee was approved March 31, 2005. This procedure (J2723) ensures fair, accurate ratings for horsepower and torque by allowing manufacturers to certify their engines through third-party witness testing. GM was the first auto manufacturer to begin using the procedure and expects to use it for all newly rated engines in the future.