components: Power Steering Pump, Power Steering
Gear, Power Steering Reservoir, Power Steering Supply,
Return and Pressure Hoses, and Power Steering Cooler.

A turn of the steering wheel is converted into lin-

ear travel through the meshing of the spur pinion
teeth with the rack teeth. Power assist steering is
provided by an open center, rotary type control valve.
It is used to direct oil from the power steering pump
to either side of the integral steering rack piston.

The firm-feel steering gear is physically the same

as the standard gear used on some models. The dif-

ference is internal. The internal calibration gives the
driver a more firm feel at the steering wheel.

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 needed to allow ease in steering and
parking. At higher speeds, higher effort is provided to
give a more firm, responsive steering feel.

POWER STEERING FLUID COOLER

All models of this vehicle are equipped with a

cooler (Fig. 1) for the power steering system fluid.
The purpose of the cooler is to keep the temperature
of the power steering system fluid from rising to a
level that would affect the performance of the power
steering system.

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STEERING

19 - 1

The power steering fluid cooler is located at the

front of the vehicle. It is mounted to the radiator
lower support just forward of the air-conditioning
condenser and just rearward of the front fascia (Fig.
1). The cooler is positioned so it is in the air flow
through the front fascia of the vehicle.

The cooler used on this vehicle is referred to as a

fluid-to-air type cooler. This means that the air flow
across the tubes of the cooler is used to extract the
heat from the cooler which it has absorbed from the
power steering fluid flowing through it. The cooler is
placed in series with the power steering fluid return
line, between the steering gear and the power steer-
ing fluid reservoir. This lowers the temperature of
the power steering fluid prior to it entering the
power steering fluid reservoir where it is resupplied
to the power steering pump.

POWER STEERING FLUID PRESSURE SWITCH

The power steering system has a power steering

pressure switch which is used to improve the vehi-
cle’s idle quality. The pressure switch improves vehi-
cle idle quality by monitoring engine idle speed and
causing idle speed readjustment as necessary, due to
increased pressure in the power steering system.
This increased pressure will slow down the power
steering pump which puts more load on the engine,
decreasing engine idle speed.

This type of condition exists when turning the

front tires of the vehicle when the vehicle is station-
ary and the engine is at idle speed. The pressure
switch signals the powertrain control module that
the power steering system is putting additional load
on the engine. When this signal is sensed by the
powertrain control module, the engine idle speed is

adjusted accordingly to maintain proper engine idle
speed and quality.

On vehicles with 2.7 liter engines, the power steer-

ing pressure switch is mounted in the power steering
pressure hose near the pump (Fig. 2).

On vehicles with 3.2 liter or 3.5 liter engines, the

power steering pressure switch is mounted in the
power steering pump (Fig. 3).

Fig. 1 Power Steering Fluid Cooler

Fig. 2 Power Steering Pressure Switch Location

With 2.7L Engine

Fig. 3 Power Steering Pressure Switch Location

With 3.2L/3.5L Engine

19 - 2

STEERING

300M

DESCRIPTION AND OPERATION (Continued)

DIAGNOSIS AND TESTING

STEERING DIAGNOSIS CHARTS

STEERING NOISE

There is some noise in all power steering systems. One of the most common is a hissing sound evident at
standstill parking. Hiss is a very high frequency noise similar to that experienced while slowly closing a water tap.
The noise is present in every valve and results in high velocity fluid passing valve orifice edges. There is no
relationship between this noise and performance of the steering. Hiss may be expected when steering wheel at
end of travel or slowly turning at standstill.

CONDITION

POSSIBLE CAUSES

CORRECTION

Objectionable Hiss Or
Whistle

1. Damaged or mispositioned steering
column coupler to dash panel seal.

1. Check for proper seal between steering
column coupler and dash seal.

2. Noisy valve in power steering gear.

2. Replace steering gear assembly.

Rattle Or Clunk

1. Steering gear loose on
crossmember.

1. Check steering gear to crossmember
mounting bolts. Tighten to specified if found
to be loose.

2. Front suspension crossmember to
frame bolts or studs loose.

2. Tighten the front suspension
crossmember attaching bolts or studs to
the specified torque.

3. Tie rod looseness (outer or inner).

3. Tighten mounting nuts to specified
torque. Check tie rod pivot points for wear.
Replace worn/loose parts as required.

4. Loose lower control arm to front
suspension crossmember bolts.

4. Tighten control arm mounting bolts to
the specified torques.

5. Lower control arm inner pivot
bushing worn.

5. Replace lower control arm pivot bushing.

6. Lower control arm tension strut
bushing worn.

6. Replace lower control arm tension strut
bushing.

7. Loose strut assembly to body
attaching bolts or nuts.

7. Check upper strut mount to body
attaching bolts or nuts for looseness. If
required tighten to the specified torques.

8. Power steering fluid pressure hose
touching the body of the vehicle.

8. Adjust hose to proper position by
loosening, repositioning, and tightening
fitting to specified torque. Do not bend
tubing.

9. Noise internal to power steering
gear.

9. Replace steering gear assembly.

10. Damaged front suspension
crossmember.

10. Replace front suspension
crossmember.

11. Stabilizer bar link ball joints worn.

11. Replace stabillizer bar link.

Chirp or squeal (in the
area of the power
steering pump).
Particularly noticeable at
full wheel travel and
during standstill parking.

1. Loose power steering pump drive
belt.

1. Adjust power steering pump drive belt to
specified tension.

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STEERING

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CONDITION

POSSIBLE CAUSES

CORRECTION

Power steering pump growl results from the development of high pressure fluid flow. Normally this noise should
not be high enough to be objectionable. Abnormal situations, such as a low oil level causing aeration or hose
touching the vehicle body, can create a noise level that could bring complaints.

Whine Or Growl (Pump
Noise)

1. Low fluid level.

1. Fill power steering fluid reservoir to
proper level and perform leakage
diagnosis. (Recheck fluid level after
power steering fluid is free of air.)

2. Power steering hose touching
vehicle body or frame.

2. Reposition power steering hose.
Replace hose if tube ends are bent.

3. Extreme wear of power steering
pump internal parts.

3. Replace power steering pump and
flush system.

4. Extremely cold temperatures of
less then zero degrees Fahrenheit.

4. Noise is typical when starting vehicle
in extremely cold temperature. Normal
duration of noisy operation is less than
one minute. If noisy operation is longer,
verify power steering fluid is at the
correct level. If level is low perform
leakage diagnosis.

Sucking Air Sound

1. Loose clamp on power steering
fluid low pressure hose.

1. Tighten or replace hose clamp.

2. Missing O-Ring on power steering
hose connection.

2. Inspect connection and replace
O-Ring as required.

3. Low power steering fluid level

3. Fill power steering fluid reservoir to
proper level and perform leakage
diagnosis.

4. Air leak between power steering
fluid reservoir and power steering
pump.

4. Inspect and or replace power
steering fluid reservoir as required.

SQUEAK OR RUBBING
SOUND

1. Sound coming from steering
column.

1. Check for squeak in steering column.
Inspect for contact between shroud,
intermediate shaft, column, and
steering wheel. Realign if necessary.
Check for lack or grease on steering
column dash panel to lower coupler
seal.

2. Sound internal to steering gear.

2. Replace steering gear assembly.

SCRUBBING OR
KNOCKING SOUND

1. Incorrect tire size.

1. Verify that tire size on vehicle is the
same as originally supplied.

2. Check clearance between tires
and other vehicle components,
through the full travel of the
suspension.

2. Correct as necessary.

3. Check for interference between
steering gear and other components.

3. Correct as necessary.

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STEERING

300M

DIAGNOSIS AND TESTING (Continued)

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