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PART 3-3-
POWER STEERING
3-33
and may be removed by hand. Re-
move any burr around the hole
in
the
torsion bar at this time to minimise
damage during assembly.
3.
The fail safe and coupling
spring can be removed if required at
this stage. Pay particular attention to
the way in which the spring is fitted,
a~
if
fitted in reverse, the sleeve will
be wrongly positioned when reas-
sembled which will cause a malfunc-
tion of the gear.
4. To remove the coupling sleeve
turn the retaining ring until one end
appears in the slot in the end of the
worm. Hook this end of the ring and
disengage it from its groove in the
worm. Withdraw the coupling sleeve
from the end of the worm, which
then allows removal of the bearing
cage.
5.
The coupling sleeve seal can
now be removed if required.
6. No further disassembly
is
pos-
sible as the torsion bar is pressed into
the worm and cannot be removed.
7. To replace the coupling sleeve
seal stretch the old seal out of the
groove in the end of the worm and
fit a new seal being careful to avoid
twisting the seal on its side or inside
out.
8. To reassemble the worm and
valve assembly replace the ball cage,
coupling sleeve and retaining ring in
that order. The seal on the end of the
worm should be smeared with a little
power steering fluid to assist the
fitment of the coupling sleeve and
after fitment, the gap in the retaining
ring should be turned to coincide
with the slot in the end of the worm.
9. Examine the seal on the end of
the torsion bar and replace it
if
it
shows any signs of deterioration or
cutting due
to
disassembly. Examine
the noise dampenin:S seal on the end
of the valve and replace if necessary.
Position the fail safe and coupling
spring on the valve exactly as it was
before removal. Position the conical
spring over the torsion bar with the
large end in the bore of the worm.
Place the split bush over the torsion
bar with the larger diameter toward
the worm. Pass the valve over the
torsion bar and locate the bush in
the end of the valve. Align the marks
made prior to removal on the valve
and torsion bar and push the valve
fully home into the lost-motion
splines of the worm. If the angular
position is correct, the master spline
on the end of the valve will line up
with the slot on the end of the worm.
The pin can now be refitted by
pressing
in,
between the jaws of a
vice.
Fitting a New Worm, Valve and
Sleeve Assembly.
If a new worm, valve and sleeve
assembly
is
to be fitted, it will be
necessary to adjust the axial position
of the assembly in the housing to
ensure that the centre point of the
worm coincides with the on centre
position of the gear. This position of
the worm valve and sleeve assembly
in the housing is adjustable by the
number of shims fitted behind the
bearing race in the housing assembly.
However, as the position of the worm
valve and sleeve assembly is varied,
so the distance the bearing spacer is
pushed into the housing must be
varied to maintain a clearance of
.010
inch between the end of the sleeve
and bearing spacer. The procedure is
as follows:-
1. Remove the sleeve from the
new worm, valve and sleeve assembly
as described above.
2. Remove the bearing race from
the housing complete with any shims
which may be fitted and refit the
bearing race without any shims using
the appropriate service tools.
3. Enter the worm and valve as-
sembly into the housing followed by
the cage assembly, race and bearing
adjusting screw. Tighten the bearing
adjusting screw sufficiently to remove
any slack (preload
is
not necessary at
this stage).
4. Refit the sector shaft assembly
and top cover (the seal from the top
cover may be removed to assist this
assembly).
5. Fit the pitman arm and nut to
the end of the sector shaft and
tighten the nut sufficiently to elimi-
nate any slack in the splines.
6. Ensure that the gear can be
rotated from lock to lock, backing
off any preload on the worm follower
if necessary, then apply preload to
the worm follower until slack is just
eliminated at one point near the on
centre position {this may not neces-
sarily be exactly on centre at this
stage).
7. Measure the actual slack at 6"
radius on the pitman arm with the
gear positioned alternatively one turn
(of the input shaft) to the left and
one turn to the right from the 'on
centre' position.
8. The clearance at the left turn
should be greater than that at the
right turn. Divide the difference be-
tween these actual readings by
5
to
obtain the correct thickness of shim
stack to be fitted.
9. Remove the sector shaft as-
sembly and worm and valve assembly
and inner race from the housing. Fit
the number of shims {as determined
above) behind the inner bearing race
and reassemble the worm and valve
assembly and sector shaft assembly
and repeat the procedure above.
10. If the difference in slack is less
than .020 inch then the shim stack is
acceptable. If the left hand slack is
greater than the right slack by more
than this amount, divide the differ-
ence by 5 and add this amount of
additional shims. If the right hand
slack is greater than the left hand by
more than .020 inch divide the dif-
ference by 5 and remove this thick-
ness of shims from the stack.
11. Confmn again that the differ-
ence in slacks are within .020 inch.
Fig. 49
Checking Steering Gear Slack
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