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2003 Chevrolet Corvette Restoration Kit
Magna Steer accomplishes this by adding or subtracting torque on the rotary input shaft to the power rack
and pinion. The amount of steering assist is dependent upon vehicle speed. As the vehicle speed
increases, the following actions occur:
•
The steering assist decreases.
•
The driver effort increases.
As the vehicle speed decreases, the following actions occur:
•
The steering assist increases.
•
The driver effort decreases.
The scan tool can
be
used to adjust the amount of steering assist if the customer requests. The steering
assist has 3 settings:
•
Factory calibration
•
More firm
•
Less firm
Variable Effort Steering Components
The MAGNASTEER® system consists of the following components:
•
The electronic brake ·control module (EBCM).
•
The MAGNASTEER® actuator
•
The power rack gear
•
The power steering pump
The Electronic Brake Control Module (EBCM)
Refer to ABS Description .
The MAGNASTEER® Actuator
The MAGNASTEER® is an integral part of the power steering gear. The MAGNASTEER® actuator
consists of the following components:
•
A rotary valve
•
A
p~rmanent
magnet that is attached to the input shaft of the rotary valve
•
Two pole pieces that are attached to the output side of the valve (the pinion)
•
An electromagnetic coil mounted in the gear housing
When the coil is energized, a magnetic field is formed between the permanent magnet and the pole
pieces, which increases the torque on the input shaft to the steering gear. The EBCM controls the current
flow to the coil. As the vehicle speed increases, the EBCM increases the current flow. The increased
current flow results in an increase in steering effort.
Other power steering system components, while specially modified for use with MAGNASTEER®, are
similar to non-MAGNASTEER® power steering components.
The Power Rack Gear
The design of the MAGNASTEER® power rack and pinion assembly is the same for a non-
MAGNASTEER® system except for valve machining differences. The steering wheel movement-transfers
to the pinion. The pinion moves the rack left or right by meshing the pinion and rack teeth. The force
transmits through the tie rod ends ·and the steering knuckles to turn the wheels.
The power rack and pinion steering system has a rotary control valve. The rotary control valve directs
hydraulic fluid from the power steering pump to the two sides of the rack piston. The piston attaches to
the rack. The attached piston uses hydraulic pressure to move the rack left or right. The rotary control
valve regulates the amount of effort by responding to the driver's torque input.
More control is maintained when the hydraulic assist is not available. More steering effort is required with
manual control.
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