steering systemsch46

8/10/2019 Steering SystemsCH46

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Steering Systems

Chapter 44


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Steering system problem diagnosis

Steering system maintenance

Steering column service

Manual steering gearbox service

(recirculating-ball type)

Steering linkage service Manual rack-and-pinion service

Power steering system service


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Symptoms of steering problems include play

in the steering wheel, hard steering, andabnormal noises when turning

Inspect and test the steering system to find

the source of the trouble


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Steering System Problems


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Steering Wheel Play

Amount that you can turn the steering

wheel without front wheel movement

Caused by worn ball sockets, a worn idlerarm, or too much clearance in the steering

gearbox

Compare the play to service manualspecifications

e.g. 1 1/2 (33 mm)


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Dry Park Test

With the vehicle on the ground, rotate the

steering wheel back and forth while

someone watches for part wear


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Steering Inspection

Raise the vehicle on a lift. Wiggle the

tires back and forth while watching

for steering play


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Hard Steering

Caused by problems with the steeringgear, power steering components, ballsockets, and the suspension system

Check the power steering pump belt forcondition and tension

If the belt is slipping, hard steering couldresult

Check for cracks and glazing and comparetension to specs


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Steering System Noise

Noise can be a sign of worn parts, drybearings or ball sockets, loose parts,slipping belts, or low power steering fluid

level Belt squeal and power steering pump

noise both occur when the steering wheelis turned

Pump noise can result from low fluid levelor aerated fluid


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Maintenance involves checking for low fluid

level, incorrect belt adjustment, system leaks,

and other problems

Ball socket lubrication may be necessary


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Checking the Fluid

Check most systems at operating

temperature, with the engine off


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Servicing the Belt

When changing a

belt, pry on a

recommendedpoint and adjust

tension to specs


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Service is needed after a collision or wheninternal parts of the column fail

Most repairs can be done without column

removal


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Steering Column


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Steering Wheel Removal

Remove the horn button and steering shaft

nut

Scribe alignment marks on the steeringwheel and the steering shaft

Mount a wheel puller over the steering

wheel

Screw the bolts into the threaded holes in

the steering wheel


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Steering Wheel Removal

Tighten the puller down against the steering

shaft to remove the wheel


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Steering Wheel Installation

When installing the steering wheel, match

any alignment marks

Many steering shafts use a master splineso that the wheel only installs in one

position

Ignition lock, turn signal mechanism, and

horn and cruise control slip rings are all

accessible below the steering wheel


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Service involves the adjustment or thereplacement of worn parts (bearings,seals, and bushings)

Gearbox repair or overhaul may benecessary when adjustment will notprovide proper operation


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Gearbox Adjustment

Two basic adjustments are performed on

manual recirculating-ball gearboxes:

Worm bearing preload

preloads the bearings to ensure that the worm

shaft is held snugly in the housing

Over-center clearance

controls the amount of lash between thepitman shaft gear and the teeth on the ball nut


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Gearbox Adjustment


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Worm Bearing Preload

Adjustment

Disconnect the pitman arm

Loosen the pitman shaft over-center locknut

and adjusting screw Using a torque wrench or spring scale, turn

the steering wheel slowly from side-to-side


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Worm Bearing Preload

Adjustment

Compare the required

force to specs

If needed, tightenor loosen the

adjustment nut


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Over-Center Clearance

Adjustment

Center the steering gear in its travel

Preload is produced in the center of travel to

avoid steering wheel play during straight-

ahead driving


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Adjustment

Loosen the locknut and bottom the

adjustment screw lightly


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Adjustment

Use a torque wrench or spring scale tomeasure the amount of force needed tomove the shaft back and forth throughcenter

Tighten or loosen the adjusting screw untilthe amount of force needed to move the

shaft is within specs Tighten the locknut after adjustment and

recheck the required force


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Adjustment


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Steering System Inspection


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Idler Arm Service

Idler arm wear will cause play in thesteering wheel

To check an idler arm, force it up and

down using a spring scale When the specified force is applied to the

spring scale each way, note the idler armmovement and compare to specs

e.g. at 20 lbs (9.0 kg) of force, maximum 1/4(6.5 mm) travel


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Idler Arm Service

To replace the idler arm, remove the cotter

pin and castle nut

Use a fork tool or puller to force the ball

stud out of the hole in the center link

Unbolt the idler arm from the frame

Install the new part

Torque the idler arm to specifications

Install a new cotter pin


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Tie-Rod End Service

Tie-rod end wear will cause steering play

To remove a tie-rod end, separate the tie-rod

end from the steering knuckle or center link


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Tie-Rod End Service

Use a fork or puller to separate the tie-rod

end from the steering knuckle


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Tie-Rod End Service

Loosen the adjusting sleeve, and count the

number of turns required to remove the tie-

rod from the sleeve


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Tie-Rod End Service

Install the new part the exact samenumber of turns

Install the tie-rod ball stud into the center

link or steering knuckle Tighten all of the fasteners to specs and

install a new cotter pin

Check toe adjustment with an alignment

machine


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Service involves the adjustment or the

replacement of worn bearings, seals, andbushings

Hoses, a pump, a power piston, and a

control valve are added these parts can require repair or replacement


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Power Steering Leaks

To check for leaks, wipe fluid-soaked

areas clean

Have a helper idle the engine and turn thesteering wheel to the right and left

Watch for leaks as the wheels are turned,

raising system pressure

L k P i


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Leakage Points(Rack-and-Pinion)


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Leakage Points(Linkage System)


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Servicing Hoses

Always check hose condition when

servicing a power steering system

High-pressure hoses are exposed to

tremendous pressures over 1000 psi (6895 kPa)

When installing a new hose, start fittings

by hand Use a tubing wrench to tighten the hose

fittings properly


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Pump Replacement

Bolts, hoses, and

brackets that must beremoved when

replacing a pump


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Pump Service

During a pump rebuild, clean and inspect

all the parts

Check the pump vanes, thrust plate, and

pump ring (included in a pump rebuild kit)

Replace all o-rings, gaskets, and seals

Lubricate the components with fluid and

reassemble the pump


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Bleeding the System

When hydraulic components are serviced,

bleed any air out of the system

Idle the engine and turn the steering wheel

fully from side to side

Check the fluid level often

Cycling the system will force air from the

steering gear, back to the reservoir

El t i A i t St i


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Electronic Assist Steering

Service

Refer to service manual diagrams, part

locations, and electrical value charts

Use a scan tool to check for diagnostictrouble codes

Check scan data for input and output data

that could help isolate a problem

Perform pinpoint tests with a multimeter to

verify the source of any problems

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