• Design strategy behind the Tundra frame and suspension
• Features and construction elements of Tundra chassis
• Benefits of Toyota's sophisticated engineering
A pickup truck's frame and suspension designs are key indicators of a vehicle's strength and poise. Chassis dynamics are often more complicated for pickups because of the extraordinary demands of hauling heavy loads and possible off-road use while still meeting Toyota's rigorous safety standards set for the entire lineup. The trend toward larger cabs also means the truck must provide a comfortable ride for the passengers.
The ladder frame is the truck's backbone, and although simple in appearance, its function is too complex to be narrowed down to a single approach. The competition brags that the frames on their ½-pickups are all fully boxed, which provides more "stiffness." But stiffness does not equate to strength. Frame strength is a combination of factors, including crossmember design and manufacturing choices. Toyota considered many factors when engineering the TripleTech™ frame.
A single method of frame construction isn't necessarily the best solution when designing a truck because some priorities may be compromised. Toyota's approach capitalizes on the benefits of three proven construction methods to deliver a frame that offers load-carrying capability, crash performance and ride quality. Here's how:
• The front section is fully boxed to support the engine weight. A robust front end also offers impact protection and provides solid mounting points for the steering and suspension components. This, in turn, improves handling response and steering precision.
• The middle section under the cab is a rolled-lip C-channel reinforced with heavy gauge steel. This design is lighter than fully boxed but still offers impact protection.
• The rear section under the bed is open C-channel—the same design used on most heavy-duty pickups for the entire frame. The open design offers a small measure of compliance under heavy load to help absorb road impacts before reaching the passenger cab.
Tundra suspension design
Toyota relies on refined proven and cost-efficient designs for the front and rear suspensions.
• Front is independent, double-wishbone with coil-over shocks. This arrangement provides consistent linear spring action when compared to some competitive models that mount the coil spring and shock absorber separately to the lower control arm.
• Rear is a traditional leaf-spring/live-axle arrangement. Leaf springs locate the axle and help control body sway. Trucks with a coil-spring rear suspension require an anti-sway bar. Toyota engineers also mounted the leaf springs in a "trapezoidal" pattern, meaning the front mounting points are wider than the rear shackles. This "towed out" design is very effective at reducing lateral axle movement and helps improve tracking when towing.
• Rear suspension features staggered shock absorbers to help reduce wheel hop under hard acceleration
If you liked this article you may enjoy this one too! http://jimmcnatttoyota.blogspot.com/2008/12/tundra-tripletech-frame-explained.html