9 - 1 4 STEERING
Right Turn (Fig. 20)
When the steering wheel is turned to the right, the worm
resists being turned because of the resistance offered by
the front wheels. The valve body also resists turning
because it is pinned to the worm. Driver force exerted at
the steering wheel turns the lower shaft and spool valve a
slight amount in relation to the valve body because of
the twisting action of the torsion bar. This slight amount
of turning of the spool valve is sufficient to position the
slots in the valve body and spool valve for power assist.
The right turn slots in the spool valve are closed off from
the return (wide) slots in the valve body and opened
more to the pressure (narrow) slots in the valve body.
The left turn slots in the spool valve are closed off from
the pressure slots in the valve body and opened more to
the return slots in the valve body.
Pressure immediately begins to build up against the
lower end of the rack-piston, forcing it upward to apply
turning effort to the pitman shaft. The oil in the
chamber at the upper end of the rack-piston is then
forced out through the valve body and spool valve
through the oil return port to the pump reservoir.
The instant the driver stops applying turning effort to the
steering wheel, the spool valve is forced back into its
neutral position by the torsion bar. Oil pressure on the
lower end of the rack-piston then decreases so that
pressure is again equal on both sides of the rack piston
and the front wheels return to the straight ahead
position when the car is moving.
Under normal driving conditions, oil pressure does not
exceed 200 psi except when turning corners where it does
not ordinarily exceed 450 psi. Oil pressure, when
parking, ranges from 900 to 1,300 psi depending upon
road conditions and weight of the vehicle. The steering
effort during normal driving, ranges from 1 to 2 lbs. and
during parking from 2 to 3-1/2 lbs. again depending
upon road conditions.
A check valve located under the high pressure connector
seat hydraulically dampens the shock transmitted to the
steering gear when driving on washboard roads.
Left Turn (Fig. 21)
When the steering wheel is turned to the left, the
relationship between the spool valve slots and valve body
slots is again changed through twisting of the torsion
bar. Pressure immediately builds up against the upper
end of the rack-piston, forcing it downward to apply
turning effort to the pitman shaft. The oil in the
chamber at the lower end of the rack-piston is forced out
through the valve body and spool valve to the pump
reservoir.
Fig. 19—Neutral Position
LIGHT DUTY TRUCK SERVICE MANUAL
Summary of Contents for Light Duty Truck 1973
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Page 53: ...HEATER AND AIR CONDITIONING 1A 27 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 115: ...LIGHT DUTY TRUCK SERVICE M A N U A L HEATER AND AIR CONDITIONING 1A 89...
Page 123: ...BODY 1B 3 Fig 6 Typical 06 Van LIGHT DUTY TRUCK SERVICE MANUAL...
Page 149: ...BODY 1B 29 Fig 84 Body Mounting 06 Fig 85 Body Mounting 14 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 171: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 2 Frame Horizontal Checking Typical FRAME 2 3...
Page 173: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 4 10 30 Series Truck Frame FRAME 2 5...
Page 174: ...2 6 FRAME LIGHT DUTY TRUCK SERVICE MANUAL Fig 5 Underbody Reference Points G Van...
Page 185: ...FRONT SUSPENSION 3 11 Fig 16 Toe out on Turns LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 351: ...ENGINE 6 15 Fig ID Sectional View of Eight Cylinder Engine LIGHT DUTY TRUCK SERVICE MANUAL...
Page 375: ...EN G IN E 6 39 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 376: ...6 4 0 ENGINE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 377: ...ENG IN E 6 41 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 378: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 37L K Series Engine Front Mount 6 42 ENG INE...
Page 400: ...6 6 4 ENG INE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 401: ...ENG IN E 6 65 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 402: ...6 6 6 ENGINE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 403: ...E NG IN E 6 67 Fig 36V C Series Engine Mounts LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 423: ...EN G IN E C OOLING 6K 13 Fig 16 Overheating Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Page 424: ...6 K 1 4 ENG INE COOLING Fig 17 Coolant Loss Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Page 456: ...6M 32 ENGINE FUEL Fig K15 Accelerator Controls G Van L 6 LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 512: ...Fig 18e Vacuum Advance Diagram V8 Engine...
Page 516: ...6 T 2 4 E M IS S IO N CONTROL SYSTEMS LIGHT DUTY TRUCK SERVICE MANUAL...
Page 528: ......
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Page 593: ...CLUTCHES MANUAL TRANSMISSIONS 7M 3 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 598: ...7M 8 CLUTCHES MANUAL TRANSMISSIONS LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 743: ...FUEL TANKS AND EXHAUST 8 13 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 744: ...8 14 FUEL TANKS AND EXHAUST LIGHT DUTY TRUCK SERVICE MANUAL...
Page 760: ...8 30 FUEL TANKS AND EXHAUST Fig 40 Exhaust Pipe P Models LIGHT DUTY TRUCK SERVICE MANUAL...
Page 761: ...FUEL TANKS AND EXHAUST 8 31 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 763: ...FUEL TANKS AND EXHAUST 8 33 LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 832: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 106 Power Steering Pump Mounting Typical 9 66 STEERING...
Page 833: ...PUMP ASSEMBLY STEERING GEAR TYPICAL SMALL V8 TYPICAL LARGE V8 STEERING 9 67...
Page 861: ...STEERING 9 95 Fig 134 Power Steering Pump Leakage LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 886: ...11 10 CHASSIS SHEET METAL LIGHT DUTY TRUCK SERVICE MANUAL...
Page 891: ...ELECTRICAL BODY AND CHASSIS 12 5 LIGHT DUTY TRUCK SERVICE MANUAL...
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