as the standard gear used on some models. The dif-
ference is internal to the gear. The internal calibra-
tion gives the driver a more firm feel at the steering
wheel. It is serviced the same as the standard steer-
ing gear.

The speed-sensitive variable-effort power steering

system, better known as speed-proportional steering,
is an electronically controlled, variable-effort type
power steering system. The steering gear has an
externally mounted control valve which in conjunc-
tion with mechanical components varies steering
effort at different vehicle speeds. At low speeds lower
steering effort is provided to allow ease in steering
and parking. At higher speeds, higher effort is pro-
vided to give a more firm, responsive steering feel.

The power steering system consists of these major

components:

• Power Steering Pump

• Power Steering Gear

• Power Steering Fluid Reservoir

• Power Steering Fluid Supply Hose

• Power Steering Fluid Pressure Hose

• Power Steering Fluid Return Hose

• Power Steering Fluid Cooler
For information on the fluid cooler, reservoir and

hoses, refer to POWER STEERING PUMP in this
section.

OPERATION - POWER STEERING SYSTEM

Turning of the steering wheel is converted into lat-

eral (side-to-side) travel through the meshing of the
helical pinion teeth with the rack teeth within the
steering gear. This lateral travel pushes and pulls
the tie rods to change the direction of the vehicle’s
front wheels.

Power assist steering is provided by a belt-driven

rotary type pump. It directs fluid through power
steering hoses to the power steering gear where it is
used to assist the driver’s turning effort.

Manual steering control of the vehicle can be main-

tained if power steering assist is lost. However,
under this condition, steering effort is significantly
increased.

Refer to POWER STEERING GEAR for informa-

tion on the operation of the speed-sensitive variable-
effort power steering.

WARNING

WARNING:

POWER

STEERING

FLUID,

ENGINE

COMPONENTS AND EXHAUST SYSTEM MAY BE
EXTREMELY HOT IF ENGINE HAS BEEN RUNNING.
DO NOT START ENGINE WITH ANY LOOSE OR DIS-
CONNECTED HOSES OR DRIVE BELTS. DO NOT
ALLOW HOSES TO TOUCH HOT EXHAUST MANI-
FOLD OR CATALYST.

CAUTION

CAUTION: During repair procedures requiring the
power steering fluid hoses to be disconnected, cap
all open ends of the hose connections. This will
prevent the entry of foreign material into the com-
ponents while the power steering hoses are discon-
nected.

STEERING

19 - 1

CAUTION: If the vehicle is equipped with the Tire
Pressure Monitoring (TPM) System, the tire/wheel
assembly needs to be reinstalled in the same loca-
tion it is removed from or the TPM System (sen-
sors) will need to be retrained. Mark each tire/wheel
assembly indicating location, prior to its removal. If
the tire/wheel assemblies are switched, rotated or
replaced, the TPM System needs to be retrained.
(Refer to 22 - TIRES/WHEELS/TIRE PRESSURE
MONITORING/SENSOR - STANDARD PROCEDURE)

DIAGNOSIS AND TESTING

DIAGNOSIS AND TESTING - POWER STEERING
FLOW AND PRESSURE TEST

ALL ENGINES

The following procedure is to be used to test the

operation of the power steering system on this vehi-
cle. This test will provide the flow rate of the power
steering pump along with the maximum relief pres-
sure. This test is to be performed any time a power
steering system problem is present to determine if
the power steering pump or power steering gear is
not functioning properly. The following flow and pres-
sure test is performed using the Power Steering Ana-
lyzer Kit, Special Tool 6815 (Fig. 1), hoses, Special
Tools 6905 and 6959, and fittings from adapter kit,
Special Tool 6893.

(1) Assemble hoses on Power Steering Analyzer,

Special Tool 6815, as shown. Install Pressure Hose,
Special Tool 6905 (in 6893 kit), in the inlet fitting on
Power Steering Analyzer. Install Pressure Hose, Spe-
cial Tool 6713 (in 6815 kit) on Pressure Hose, Special
Tool 6905. Install Pressure Hose, Special Tool 6959,
in the outlet fitting on Power Steering Analyzer.

Install the following adapters from Adapter Set,

Special Tool 6893 (Fig. 2), on the analyzer hose ends:

• 2.7L engine — Install Adapter Fitting, Special

Tool 6844, on Pressure Hose, Special Tool 6713.

• 3.5L engine — Install Adapter Fitting, Special

Tool 6825, on Pressure Hose, Special Tool 6713.

• All models — Install Adapter Fitting, Special

Tool 6826, on Pressure Hose, Special Tool 6959.

WARNING:

PREVENT

PERSONAL

INJURY,

SAFETY GOGGLES SHOULD BE WORN AT ALL
TIMES WHEN PERFORMING ANY TEST PROCE-
DURES ON THE POWER STEERING PUMP OR
POWER STEERING GEAR.

The following procedure is to be used to test the

operation of the power steering system on the vehi-
cle.

(2)

Check belt tension and adjust as necessary.

NOTE: On vehicles with 3.5 liter engines, it may be
easier to access the power steering pump pressure
fitting from the bottom of the vehicle engine com-
partment.

Fig. 1 Power Steering Analyzer With Hoses Installed

1 - OUTLET
2 - SPECIAL TOOL 6815
3 - INLET

Fig. 2 Power Steering Analyzer Adapters 6893

19 - 2

STEERING

STEERING (Continued)

(3)

Disconnect the power steering fluid pressure

hose from the power steering pump (Fig. 3) (Fig. 4).

(4) 2.7L engine — Connect Adapter Fitting, Spe-

cial Tool 6844 (Fig. 5), attached to pressure hose from
inlet (gauge end) of Power Steering Analyzer to the
pressure fitting on the power steering pump.

(5) 3.5L engine — Connect Adapter Fitting, Spe-

cial Tool 6825 , attached to pressure hose from inlet
(gauge end) of Power Steering Analyzer to the pres-
sure fitting on the power steering pump (Fig. 6).

Fig. 3 Pressure Hose Connection To Power Steering

Pump (2.7L Engine)

1 - POWER STEERING FLUID PRESSURE HOSE

Fig. 4 Pressure Hose Connection To Power Steering

Pump (/3.5L Engine)

1 - POWER STEERING PUMP
2 - POWER STEERING FLUID PRESSURE HOSE

Fig. 5 Analyzer Connected To Power Steering Pump

(2.7L Engine)

1 - POWER STEERING FLUID PRESSURE HOSE

Fig. 6 Analyzer Connected To Power Steering Pump

(/3.5L Engine)

1 - POWER STEERING PRESSURE HOSE
2 - POWER STEERING PUMP

STEERING

19 - 3

STEERING (Continued)

(6) Connect vehicle power steering fluid pressure

hose to Adapter Fitting, Special Tool 6826, which
should be already installed in the outlet hose (valve
end) of Power Steering Analyzer.

(7) Completely open valve on Power Steering Ana-

lyzer.

(8) Start engine and let idle long enough to circu-

late power steering fluid through the analyzer and
hoses, until the air is out of the fluid. Shut off
engine.

(9) Check power steering fluid level and add fluid

as necessary. Start engine again and let idle.

(10) Gauge should read below 862 kPa (125 psi), if

above, inspect the hoses for restrictions and repair as
necessary. The initial pressure should be in the range
of 345-862 kPa (50-125 psi).

CAUTION: The following test procedure involves
testing maximum pump pressure output and flow
control valve operation. Do not leave valve closed
for more than five seconds as the pump could be
damaged.

(11) Close valve fully three times and record high-

est pressure indicated each time. All three read-
ings must be above specifications and within
345 kPa (50 psi) of each other.

NOTE: Power steering pump maximum relief pres-
sure is 8275 to 8975 kPa (1250 to 1350 psi.).

• Power steering pump pressures above specifica-

tions but not within 345 kPa (50 psi) of each other,
replace pump.

• Pressures within 345 kPa (50 psi) of each other

but below specifications, replace pump.

CAUTION: Do not force the pump to operate against
the stops for more than 2 to 4 seconds at a time
because, pump damage will result.

(12) Completely open the valve on the Power

Steering Analyzer. Turn the steering wheel to the
extreme left until the stop in the steering gear is
met, then turn the steering wheel to the right until
the right stop is met. Record the highest indicated
pressure at each position. Compare the recorded
readings to the specifications. If the highest recorded
output pressure reading against one stop is not
within 345 kPa (50 psi) of the highest recorded read-
ing at the other stop, the steering gear is leaking
internally and must be replaced.

DIAGNOSIS AND TESTING - STEERING
DIAGNOSIS CHARTS

NOTE: There are three diagnosis charts following
that cover POWER STEERING NOISE, STEERING
WHEEL FEEL, and POWER STEERING FLUID.

19 - 4

STEERING

STEERING (Continued)

Content .. 275 276 277 278 ..