MCi MC8 Crusader - Steering Gear; Description and Operation

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Crusader

MC-8

[ "°' 11-2

Stop

at

the

instant

the

road

wheels

starf

to

move.

6.

Mark

the

steering

wheel

again

in

line

with

a

poin-

ter.

Measure

the

distance

between

the

two

marks,

either

in

inches

(millimeters)

at

the

rim

or

as

an

angle

with

its

apex

at

the

steering

wheel

center.

This

measurement

must

not

be

over

2"

(50.8

mm)

or

10°

0

2" (50

.8

mm)

or

10

with

no

movement

at

Front Road

Wheels

NOTE:

THE

ABOVE

READING

MUST

BE

TAKEN

WITH

ENGINE

RUNNING.

FILLING

POWER

STEERING

SYSTEM:

When

the

power

steering

hydraulic

fluid

system

is

drained,

or

if

any

lines

or

connections

are

removed,

it

is

necessary

to

bleed

air

completely

from

the

system

to

ensure

satisfactory

operation.

HYDRAULIC

SYSTEM:

Use

SAE

No.

I

OW

motor

(Service

MS).

Fill

the

reservoir

to

the

recommended

level

as in-

dicated

on

the

reservoir.

If

the

level

is

higher,

over-

flow

will

occur

during

operation.

If

the

level

gets

too

low,

air

will

be

drawn

into

the

system.

The

proper

refilling

and

bleeding

procedure

is as

follows:

Raise

front

end

of

vehicle

until

wheels

clear

the

floor.

Fill

the

power

steering

fluid

reservoir,

located

in

the

engine

compartment,

to

the

FULL

mark.

Allow

the

fluid

to

remain

undisturbed

for

about

two

minutes.

Turn

wheels

to

left

and

right

in

order

to

remove

air

from

the

power

steering

cylinder,

adding

fluid

to

the

reservoir

as

needed

to

maintain

level

to

the

FULL

mark.

Continue

until

air

bubbles

no

longer

show

in

the

reservoir.

Start

engine

and

operate

on

idle

speed.

Turn

wheels

to

right

and

left,

but

do

not

hit

wheel

stops.

Add

fluid

as

needed

at

the

reversor

until

half

way

in

MAINTENANCE

DATE-

__

]

MANUAL

June

15,

1974

.

the

sight

gauge.

Continue

until

all

air

bubbles

disap-

pear

at

the

reservoir.

Increase

engine

speed

to

2/3

of

full

throttle,

continuing

the

procedure

outlined

above.

Lower

the

vehicle

front

end

and

turn

wheels

to

right

and

left

a

few

more

times.

Check

for

fluid

leaks.

Add

fluid

to

reservoir

until

half

way

in

the

sight

gauge.

LUBRICATION:

Use

SAE

90

gear

lubricant.

Fill

the

steering

gear

housing

with

lubricant.

Fill

the

housing

from

the

uppermost

filler

plug.

The

housing

should

be

full

to

ensure

adequate

lubrication

of

all

internal

parts.

Capacity

of

the

gear

housing

is 7

pints

(3.30

dm

3

).

STEERING

GEAR

DESCRIPTION

AND

OPERATION

The

power

steering

gear

is a

semi-integral

hydraulic

unit

which

incorporates

a

hydraulic

con~rol

,

valve

on

a

twin

stud

cam

and

lever

mechanical

steering

gear.

Steering

effort

applied

to

the

steering

wheel

actuates

the

valve

which,

in

turn,

directs

hydraulic

fluid

from

the

pump

to

the

power

cylinder

located

in

the

linkage.

The

action

of

the

steering

gear

is

both

manual

and

hydraulic

in

effect.

When

the

cam

is

turned

to

the

left

or

right

by

the

driver's

effort

on

the

steering

wheel,

the

studs

of

the

inner

lever

are

moved

through

the

groove

of

the

cam

(worm),

thus

rotating

the

lever

shaft

and

providing

angular

movement

of

the

steering

gear

pitman

arm.

Whenever

the

driver's

effort

at

!he

steering

wheel

exceeds

the

preload

of

the

centering

springs,

the

control

valve

is

actuated

and

t_he

hydraulic

power

is

applied

to

provide

the

driver

with

power

assistance.

The

valve

spool

is

moved

axially

as

the

cam

is

moved

axially

although

these

parts

are

restrained

from

axial

movement

by

the

centering

springs

in

the

actuator.

The

effect

of

the

springs

is

to

center

the

ac-

tuator

and

valve

spool

(unless

the

steering

force

is

great

enough

to

overcome

the

spring

load

in

which

case

the

actuator

and

spool

are

moved

axially.)

When

the

valve

is

in

the

center

position,

the

oil

pressure

at

the

two

cylinder

ports

is

low

and

equal

and

produces

ineffective

forces

in

the

cylinder.

This

results

in

no

movement

of

the

piston

and

no

cir-

culation

of

oil

in

the

lines

to

the

cylinder,

however,

oil

is

circulating

from

the

pump

through

the

control

valve

to

the

reservoir

with

sufficient

pressure

only

to

overcome

friction

of

lines

and

fittings.

When

the

driver's

effort

at

the

steering

wheel

over-

comes

the

centering

effect

of

the

springs,

the

valve

spool

is

moved

axially

restricting

one

of

the

return

passages

to

the

outlet

port

thus

causing

an

immediate

increase

in

pressure

at

one

of

the

ports

and

in

one

end

of

the

cylinder.

At

the

same

time,

the

other

return

passage

is

enlarged,

allowing

the

oil

from

the

discharging

end

of

the

cylinder

free

passage

to

the

outlet

port

and

return

to

the

reservoir.

The

im-

mediate

effect

is

increased

pressure

in

one

end

of

the

cylinder

to

actuate

the

piston

which

applies

hydraulic

power

directly

to

the

steering

gear

pitman

arm.

Full

pressure

is

obtained

with

a

valve

spool

travel

in

one

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