The MAGNASTEER system consists of the following components:
| • | The electronic brake traction control module (EBTCM). |
| • | The MAGNASTEER actuator |
| • | The power steering pump |
The Electronic Brake Traction Control Module (EBTCM)
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 permanent 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 EBTCM controls the current flow to the coil.
As the vehicle speed increases, the EBTCM 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.
The Power Steering Pump
A constant displacement van-type pump performs the following services
for the steering system:
| • | Provides hydraulic pressure |
The power steering pump and the engine crankshaft pulleys drives the
pump. The opening at the rear of the pump housing contains the following components:
The pump housing side contains the pressure line fitting. The pressure
relief valve inside the flow control valve limits the pump pressure.
