57STEERING
4
OVERHAUL Sector shaft cover assembly
31.Inspect cover and bearing. If worn or damaged,
replacement parts are not available, fit a new
steering box.
Sector shaft adjuster locknut
32.The locknut is also a fluid seal. Fit new nut at
overhaul.
Valve and worm assembly
33.Examine bearing areas for wear. The areas must
be smooth and not indented.
34.Examine worm track which must be smooth and
not indented.
35.Check for wear on torsion bar assembly pin. No
free movement should exist between input shaft
and torsion bar or between torsion bar and
worm.
NOTE: Any sign of wear makes it essential
to fit new valve and worm assembly.
36.Examine valve rings for cuts, scratches and
grooves. The valve rings should be free to rotate
in grooves.
37.If required, replace all three rings, using ring
expander LRT-57-019. The expander will not
pass over rings already fitted. Remove rings to
allow access without damaging seal grooves.
38.Warm rings and expander tool to aid assembly.
Fit rings to expander, slide expander over valve
and worm assembly. In turn fit rings to their
grooves. Remove expander, slide valve and
worm assembly into ring compressor
LRT-57-020 and allow to cool.
Ball bearing and cage assemblies
39.Examine ball races and cups for wear and
general condition.
40.If ball cage has worn against bearing cup, fit
replacements.
41.Bearing balls must be retained by cage.
42.Bearing and cage repair is carried out by
complete replacement of assembly.
57STEERING
6
OVERHAUL
61.Fit new worm adjuster sealing ring.
62.Loosely screw adjuster into casing.
63.Fit locknut, do not tighten.
64.Turn in worm adjuster until end float is almost
eliminated. Ensure bearing cages are seated
correctly.
65.Measure maximum rolling torque of valve and
worm assembly, using a torque wrench and
spline socket LRT-57-025.
66.Turn in worm adjuster while rotating shaft to
increase figure measured in instruction 65. to
0.56 Nm.
67.Back off worm adjuster 1/4 turn. Turn in worm
adjuster to increase reading at 65. by 0.21 - 0.34
Nm with locknut tight,
100 Nm.Use worm
adjusting wrench LRT-57-006 and locknut
wrench LRT-57-028.Fitting rack and piston
68.Screw slave bolt into piston to aid assembly.
69.Fit piston and rack so piston is 70 mm from outer
end of bore.
Fitting sector shaft
70.Fit sector shaft using seal saver LRT-57-021.
Align roller with cut out in casing - see
RR3934M. Push in sector shaft while rotating
input shaft to allow sector roller to engage worm.
Fitting rack adjuster
71.Fit rack adjuster and thrust pad to engage rack.
Back off half turn on adjuster.
72.Loosely fit new nylon pad and adjuster set screw
assembly.
STEERING
7
OVERHAUL Fitting sector shaft cover
73.Fit new sealing ring to cover.
74.Align cover with casing.
75.Screw cover assembly fully on to sector shaft
adjuster screw.
76.If necessary back off sector shaft adjuster screw.
Tap cover in place to allow cover to joint fully
with casing.
NOTE: Before tightening fixings, rotate
input shaft to ensure sector shaft roller is
free to move in valve worm. If initial
resistance is left, turn adjuster screw
approximately two turns in a clockwise direction.
77.Fit cover bolts. Tighten to
75 Nm.
Fitting cylinder cover
78.Fit new square section seal to cover.
79.Remove slave bolt fitted at instruction 68. Press
cover into cylinder just to clear retainer ring
groove.
80.Fit retaining ring to groove with one end of ring
positioned 12 mm from extractor hole.
Adjusting sector shaft
NOTE: Refit drop arm and tighten nut
sufficiently to ensure that no backlash
exists between drop arm and sector shaft.
81.To set worm on centre, rotate input shaft to full
inner-lock (full right lock for a left hand drive
vehicle, full left lock for a right hand drive
vehicle). Rotate input shaft back towards centre
two full turns.
82.The box is now on centre and can be adjusted.
57STEERING
8
OVERHAUL 83.Hold input shaft and rock drop arm to establish
backlash is present. Continue rocking and slowly
turn sector shaft adjusting screw clockwise.
Continue rotating adjuster screw until backlash
has almost been eliminated.
84.Refit locknut and tighten.
NOTE: It is important steering box is
centralised before any adjustments are
made.
85.Check maximum rolling torque one and a quarter
turns either side of centre position, using a
torque wrench and spline socket LRT-57-025.
Rotate adjuster screw to obtain across centre
torque of 0.34 Nm plus torque figure at one and
a quarter turns. Tighten adjuster locknut to
60
Nm.
Adjusting rack adjuster.
86.Turn in rack adjuster to increase figure
measured in instruction 85. by 0.23 - 0.34 Nm.
The final figure may be less, but must not
exceed 1.35 Nm.
87.Lock rack adjuster in position with grub screw.
Tighten to
5 Nm.
Torque peak check
With input shaft rotated from lock to lock, rolling
torque figures should be greatest across centre
position and equally disposed about centre position.
The condition depends on value of shimming fitted
between valve and worm assembly inner bearing cup
and casing. The original shim washer value will give
correct torque peak position unless major components
have been replaced.Procedure
88.With input coupling shaft toward the operator,
turn shaft fully counter-clockwise.
89.Check torque figures obtained from lock to lock
using torque wrench and spline socket
LRT-57-025.
90.Check also for equal engagement either side of
centre.
Adjustments
91.Note where greatest figures are recorded
relative to steering position.If greatest figures are
not recorded across centre of travel (steering
straight-ahead), adjust as follows:
If torque peak occursbeforecentre position,addto
shim washer value; if torque peak occursaftercentre
position,subtractfrom shim washer value,
refer to
fitting valve and worm assembly
.
Shim washers are available as follows:
0.03mm, 0.07mm, 0.12mm and 0.24mm.
NOTE: Adjustment of 0.07mm to shim
value will move torque peak area by 1/4
turn on the shaft.
CAUTION: When reshimming valve and
worm, extreme caution must be exercised
to prevent seal damage during
reassembly.
STEERING
1
SPECIFICATIONS, TORQUE STEERING PUMP
Make/type - V8i ZF 'Unicorn'................................................................
Make/type - Tdi Hobourn Eaton 500 series................................................................
Operating pressure - straight ahead position - at idle 7 bar, 100 lbf/in
2maximum ......
Full lock (left or right) at idle 28 bar, 400 lbf/in2minimum .............................................
Full lock (left or right) 1000 rev/min 70-77 bar, 1000-1100 lbf/in2..................................
57STEERING
2
SPECIFICATIONS, TORQUE TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
Ball joint nuts 40..............................................................................................
Clamp bolt nuts 14..........................................................................................
Steering column bracket nuts 22....................................................................
Steering wheel nut 50.....................................................................................
Tie bar to mounting nut 110.............................................................................
Universal joint pinch bolt 25............................................................................
PAS box
Adjuster locknut 60.................................................................................
Drop arm nut 176....................................................................................
Sector shaft cover to steering box 75.....................................................
Steering box to chassis 81.....................................................................
Steering box fluid pipes 14mm thread 15...............................................
Steering box fluid pipes 16mm thread 20...............................................
Tie bar 81...............................................................................................
PAS pump
High pressure fluid pipe 20.....................................................................
Power steering pump mounting 35.........................................................
Pulley bolts, power steering pump 10....................................................
Hose clamp 3........................................................................................
Front mounting plate bolts 9..................................................................
PAS reservoir
Hose clamp 3........................................................................................
* Torque values below are for all screws and bolts used except for those that are specified otherwise.
METRIC Nm
M5 6......................................................................................................
M6 9......................................................................................................
M8 25.....................................................................................................
M10 45...................................................................................................
M12 90...................................................................................................
M14 105..................................................................................................
M16 180..................................................................................................
UNC / UNF
1/4 9......................................................................................................
5/16 24...................................................................................................
3/8 39.....................................................................................................
7/16 78...................................................................................................
1/2 90.....................................................................................................
5/8 136....................................................................................................
FRONT SUSPENSION
1
REPAIR SELF LOCKING NUTS
WARNING: Where self locking nuts are
removed, they must be replaced with new
nuts of same specification.
PANHARD ROD
Service repair no - 60.10.07.
Remove
1.Remove fixings at mounting arm.
2.Remove fixings at axle bracket.
3.Remove Panhard rod.
4.Press out flexible bushes. Ensure the steel
tubing locates on the outer edge of the bush and
not on the rubber inner.
Refit
5.Fit replacement bushes.
CAUTION: Apply pressure to outer edge of
bush, and not rubber inner.
6.Reverse removal procedure. 1 to 4. Tighten to
88Nm
RADIUS ARM
Service repair no - 60.10.16.
Remove
1.Loosen road wheel retaining nuts.
2.Raise front of vehicle. Support chassis on stands
and remove wheel.
3.Support front axle weight with jack.
4.Remove radius arm to chassis side member
fixings.
5.Disconnect track rod at ball joint.
6.Remove fixings, radius arm to axle.
7.Lower radius arm front end to clear axle and
remove from vehicle.
FRONT SUSPENSION
3
REPAIR 7.Withdraw lower seating washer, rubber bush and
cupwasher.
8.Remove fixings, shock absorber to mounting
bracket.
9.Withdraw mounting bracket.
10.Lift off top seating washer, rubber bush and
cupwasher.
Refit
11.Reverse removal procedure. 1 to 10.FRONT ROAD SPRING
Service repair no - 60.20.11.
Remove
1.Remove front shock absorber.
See Front
Shock Absorber
CAUTION: Avoid over stretching brake
hoses. If necessary loosen hose connector
locknuts to allow hoses to follow axle.
2.Lower axle sufficient to free road spring.
3.Withdraw road spring.
4.Withdraw shock absorber bracket securing ring.
Refit
5.Fit shock absorber bracket retaining ring. Retain
in position with a nut.
6.Reverse 2 and 3.
7.Remove nut retaining securing ring.
8.Fit front shock absorber.