Defender (1993+). Manual — part 73

STEERING

NOTE: The steering box has now been

2.

Check the condition of the adjuster thread and

dismantled except for the sector shaft bushes,

that there is no excessive vertical play. A

shown dotted. Since replacement bushes are not

movement of 2 mm

I

S

acceptable. Side play,

available, they should not

be

removed. The input

however, is of no significance.

shaft inner bearing cup and shims may also still

3.

Examine the bearing surfaces of the shaft for

be

i n position if jarring of the box has not

wear, scores and pitting.

already

dislodged them and instructions

for

4. Check the gear teeth for excessive or uneven

removing these appear later.

wear, scores and pitting.

5.

Examine the cover for damage and burrs.

INSPECTION

Remove and discard the seal. Check the bush

for wear and scores. Also check the adjuster

Steering

box casing

6.

Check the bleed nipple and threads and that

the bleed whole in the inside of the cover is

1.

Examine the piston bore for wear, scores and

pitting.

2.

Examine the inlet pipe thread in the side

of

the cylinder tube for damage and if necessary

NOTE: For replacement purposes, the cover,

repair using

a

suitable tap.

bush and seal are supplied as

a complete

cracks and dents and renew if in any way
faulty.

7.

The locknut, which should be discarded, also

4.

Since it is very unusual for the sector shaft

acts as a fluid seal and a new one should be

bushes to wear they are not available as

fitted on assembly.

replacements.

However,

they

should

nevertheless be checked for damage.

3.

Check the feed pipe for damage especially for

assembly.

Sector shaft and cover assembly

1.

Check that there

is

no side play on the roller.

If excessive play

does

exist the sector shaft

should be renewed likewise if any of the
following checks are unsatisfactory.

12

REISSUED:

FEB

1993

thread for damage

clear.

STEERING

Valve and worm assembly

1.

Examine the bearing areas for wear. The

surfaces must be smooth and free from
indentations, scores and pitting.

2. Examine the worm for wear which must also

be smooth and free

of

scores

and

indentations.

3.

Check for any wear on the torsion bar
assembly pins. Grip the splined end of the
input shaft in a soft jawed vice and by hand
twist the worm end.

No

free movement should

exist between the input shaft and worm.

NOTE:

If

any wear does appear in the above

areas it is essential that a new valve and worm
assembly

is fitted.

6. Remove the expander tool and slide the

compressor tool

RO

606603

over the rings,

internal chamfered end leading and leave until
cool.

4.

Examine the valve rings which must be free

from cuts, scratches and grooves. The valve
rings must be a loose fit in the valve grooves.
If

any one

of

the rings is faulty,

all

the rings

must be renewed. Take care not to damage

the ring grooves when removing the rings.

5.

Fit replacement rings using expander tool

RO

606602. Expand the rings by immersing them
in hot water until pliable then carefully slide
the rings over the

tool,

from

the chamfered

end. Place the

tool

over the ring grooves and

slide the first ring into the groove nearest

to

the worm and

so

on until the third ring

is

in

place.

It

is important to fit the rings

in

this

sequence since the tool will not pass over the
rings.

REISSUED: FEB 1993

13

STEERING

2.

To

remove the inner bearing cup and shims

jar the casing on the work bench or use a

suitable extractor. Alternatively, if difficulty is

being

experienced,

warm

the

casing

universally

in

an oven or in boiling water.

Do

not, however, attempt to apply local heat since

distortion

of

the casing may result. Whilst the

casing is being heated, cool a suitable
mandrel

or

round bar

to

fit inside the bearing

cup. Insert the cooled bar

in

the heated

casing to retract the cup to enable it to be
withdrawn together with the shims which must

be

retained for reassembly.

Ball bearing and cage assemblies

Rack and piston

NOTE:

That beneath the visible white Nylon ring

in

the piston groove, there is a rubber seal.

1.

Examine the valve and worm inner and outer
ball races and cups and if either is worn,

pitted or damaged in any way, both the cups
and the ball races must be renewed.

1.

Examine the outer seal and if worn or

damaged in any way it must be renewed
along with the rubber ring.

2.

Taking care not to damage the piston outer
diameter remove the plastic seal.

3. Likewise, carefully remove the rubber ring.

4. Examine the rack teeth

for

wear and damage.

5.

Check that the thrust pad bearing surface is

free

from wear and scores.

6. Check the piston outer diameters for burrs

and damage and repair as necessary using a
fine file and emery cloth.

7. Ensure that the bottom

of

the groove and the

inside walls are not damaged or burred.

Repair where necessary in the same way as

above

14

REISSUED:

FEB

1993

STEERING

8. Fit a new rubber ring to the piston groove.

ASSEMBLE

Warm a new white Nylon seal in hot water
and

fit

to the piston.

NOTE: When fitting replacement oil seals, these

9.

Immediately, whilst still warm, carefully insert

must

be lubricated, before fitting, with the

the piston squarely into the casing bore with

recommended steering

box fluid.

Also

ensure

the rack outwards, as illustrated, and leave

that absolute cleanliness is observed throughout

until cool.

the following assembly instructions.

Fitting input shaft oil seal

1.

Fit a new seal, lipped side first, into the
housing noting that when correctly fitted the
seal backing will seat on the first shoulder in

the bore.

2.

Insert the extrusion washer

with

the flat side

downwards facing the seal. Secure the
assembly with the circlip and

to

ensure that it

is properly located, tap the circlip into the
groove with a punch.

Rack thrust pad and adjuster

1.

Examine the rack pad adjuster for general

condition particularly the pad bearing surface.

2.

Renew the seal and if necessary the nylon

thrust pad behind the grub screw.

3. Check the thrust pad for wear in particular the

flat side which slides on the reverse side of
the piston rack.

REISSUED:

FEB

1993

15