|
Strength
and
Rigidity
Hydroformed
Frame
Independent
Front
Torsion Bar
Five-Link
Coil Spring
Rear
Suspension
Premium
Smooth
Suspension
Solid
Smooth
Suspension
New
Autoride
Suspension
Tow/Haul
Mode
Precise
Steering
Shorter
Turning Radius
Wider Track
Improved
Braking
Improved
Braking
Electronic
Traction
Assist
AutoTrac
|
AutoWorld.com -DETROIT - World-class ride and handling in the all-new GMC Yukon and Yukon XL is
exhibited in a smooth ride with agile maneuverability. The impressive ride results from
a stiffer body and chassis, a new independent torsion bar front suspension, rear five-link
coil suspension on 1/2-ton models, and available Autoride suspension package. The new
Yukons' agility is derived from a shorter turning radius, wider, more stable body, rigid
frame, precise variable-effort steering and larger brakes.
The Yukons' exceptionally strong, stiff body structure produces minimal vibration, even
on an extremely bumpy road. The uniquely designed three-piece modular frames provide
the foundation for the outstanding body strength and structural rigidity. The approximately
23-percent increased stiffness of major body sections is double that of its predecessors.
The full-length box frame on the 1/2-ton models features a stamped steel midsection and
hydroformed front and rear rails and supports. GM was the first to use the hydroforming
process on its frames which increases strength, reduces weight, eliminates hundreds of
inches of welds and provides a more precisely engineered, solid foundation for attach-
ing the suspension system. Where required, welds replace rivets to provide added strength
and durability.
An independent front torsion bar suspension -a premium feature commonly found only
on four-wheel-d rive models - is now standard on all Yukons. The suspension has been
specially tuned for more on-center steering feel and maneuverability to enhance vehicle
control.
All 1/2 ton Yukons also feature a totally new five-link, coil spring rear suspension to enhance
ride smoothness. The two upper control arms are forged steel. The two lower control
arms
are open section steel stampings with bushings on each end and a rubber isolator and
outer sleeve for improved road isolation. Together the control arms manage the vehicles'
vertical position and fore and aft movement. A fifth link, or track bar, restrains the
vehicle's side-to-side movement.
Yukon and Yukon XL 1/2-ton models feature a standard Premium Smooth Ride
suspension package with self-leveling shocks for improved handling and a firm touring ride.
This package includes touring tires and high-performance shock absorbers. As an aid
to heavy hauling and trailering, its self-leveling rear shocks maintain the vehicle's rear
suspension at the proper height and operate as part of a self-contained system relying
on road inputs, such as bumps, for their activation. In addition, a specially designed optional Off-Road Suspension package available on the
four-wheel-drive Yukon tunes springs, shocks, jounce bumpers and stabilizer bars to
minimize the impact of punishing road surfaces. It includes large, aggressively treaded tires
that maximize traction in loose soil.
Standard on 3/4-ton Yukon XL is the Solid Smooth Ride suspension which features two-stage
leaf springs and gas shocks designed for heavier loading. The first stage offers a smooth
ride under empty to moderate loads and the second stage adds greater load-carrying
capability under heavy loads. An optional trailering suspension on the 3/4-ton Yukon XL improves handling during
heavy trailering with retuned shocks and stiffer springs for increased roll damping and
firmer ride.
As a further enhancement, Yukon offers a new Autoride suspension package. Autoride
controls shock damping to optimize ride under any conditions - whether the truck is
loaded or unloaded, pulling a trailer or not. It provides the greatest benefit in heavy
trailering. Autoride continually senses different road surfaces, speeds, steering, braking,
load and wheel height conditions and selects the best suspension damping level to fit
the driving conditions. A computer, used to determine the optimal damping level at each
wheel of the truck, can change shock damping on a continual, 20-millisecond basis,
if needed.
On 1/2.-ton models, the new Autoride system also uses a new compressed-air, rear-leveling
system that automatically maintains the vehicle's proper height under all load conditions.
The system uses sensors, attached between the frame and rear suspension, to monitor
rear wheel height. When necessary, the sensors send out a signal to a compressor that
automatically pumps the rear shocks up to the required height for a level ride regardless of
conditions.
Autoride is incorporated into the Tow/Haul mode which is engaged by pushing a button
on the shift lever. GM's exclusive Tow/Haul mode reduces shift busyness and wear
when pulling a heavy trailer.
Variable-effort power steering is standard on four-wheel-drive Y2-ton Yukon models.
This system adapts the required steering effort to the vehicle speed, providing more
responsive feel and stability at highway speeds, for example, and reduced effort for
parking maneuvers.
The all-new Yukons deliver a more stable ride with their wider tracks. Yukon and Yukon XL
1/2-tons are 2.4 inches wider in the rear and 2.5 and 1.0 inches wider in the front on two-and four-wheel-d rive models, respectively.
All Yukons have tighter turning circles making them very maneuverable in tight spots.
Yukon has a 1.5-foot and 2.4-foot tighter turning diameter for two- and four-wheel drive
models, respectively. The Yukon XL V2-ton has 1.4-foot and 2.4-foot tighter turning
diameters for its two- and four-wheel-drive models.
Yukon provides quicker stops and more steering control during hard braking with a
standard four-wheel disc/four-wheel antilock brake system that features 40-percent
larger front brake pads and rotors. The larger components also increase brake life by
up to 400 percent. The use of a dedicated Electronic Brake Controller (EBC) also helps
optimize brake system performance.
The brake system includes GM's exclusive Dynamic Brake Proportioning (DBP). DBP
is an electronic system that determines changes in wheel speed and load variation to
adjust the amount of pressure applied to the rear brakes. At any given time, DBP helps
optimize the power of the rear braking system by keeping it in proper balance with the
front brakes for short, controlled stops whether the vehicle is loaded or unloaded.
Two-wheel-drive 1/2-ton Yukons offer a new Electronic Traction Assist (ETA) system for
more controlled acceleration and stability on slippery surfaces. It manages the power-
train by retarding spark, reducing airflow and modifying transmission shifts and works
in conjunction with a limited-slip/locking rear axle to optimize traction and stability.
The system controls traction at all speeds, reacting to key emergency situations faster
than the typical driver. For example, if cruise control is active and the vehicle hits a patch
of ice, the system will immediately deactivate the cruise control and seek to regain
stability by reducing torque to the rear wheels.
Four-wheel-drive Yukons also continue to include AutoTrac as a standard feature. This
active transfer case allows a truck to get all of its traction from the rear wheels until it
senses slippage. At that point, AutoTrac automatically switches power between the rear
and front wheels until the vehicle regains traction. Thereafter, it allows the vehicle to
resume full rear-wheel drive, and returns to standby mode until another wheel speed
differential occurs.
If AutoTrac detects multiple, large slip events for a sustained period of time, it locks into
the 4HI mode. After a few moments, it returns to the automatic four-wheel-drive standby
mode. In addition to other benefits, neutral is available with AutoTrac which allows the
Yukon to be flat-towed behind a recreational vehicle.
|
