MAINTENANCE
3
MAINTENANCE VEHICLE EXTERIOR
CHECK/ADJUST HEADLAMP ALIGNMENT
Check/adjust headlamp and auxiliary alignment.
CHECK FRONT WHEEL ALIGNMENT
Use recognised wheel alignment equipment to
perform this check and adjustment.
See STEERING,
Adjustment, Front Wheel Alignment
REMOVE WHEELS, CHECK TYRES
Check tyres (including spare) for compliance with
manufacturers' specification.
Check visually for cuts, lumps, bulges, uneven tread
wear and tread depth. Check road wheels for
damage.
Check/adjust tyre pressures.
CHECK/TIGHTEN TOWING BRACKET FITTINGSINSPECT BRAKE PADS FOR WEAR, CALIPERS
FOR LEAKS AND CONDITION
Check thickness of brake pads, fit new pads if
minimum thickness is less than 3,0mm. Check brake
pads for oil contamination. If new brake pads required.
See BRAKES, Repair, Front Brake Pads
or.See BRAKES, Repair, Rear Brake Pads
WARNING: When renewing brake pads, it
is essential that only genuine components
with correct grade of lining are used.
Always fit new pads as complete axle sets, NEVER
individually or as a single wheel set. Serious
consequences could result from out of balance
braking due to mixing of linings.
Refit road wheels
Fit road wheels in original hub position. Secure in
position with wheel nuts, do not fully tighten wheel
nuts at this stage, lower vehicle and finally tighten
wheel nuts to correct torque.
Alloy wheels:
130 Nm.
Steel wheels:130 Nm.
LUBRICATE ALL HINGES, DOOR CHECK
MECHANISMS, BONNET [HOOD] CATCHES AND
FUEL FILLER FLAP
12ENGINE
8
REPAIR CAMSHAFT DRIVE BELT AND GEARS
Service repair no - 12.65.18
TIMING BELT
Remove
1.Remove front cover plate.
See Front Cover
Plate
2.Position engine at TDC on No. 1 cylinder.
3.If manual gearbox: Remove blanking plug from
flywheel housing and insert timing tool
LRT-12-044. If EDC - timing tool LRT-12-085
must be used.
If automatic gearbox:Sited to the rear of the
engine sump on engine backplate is a blanking
plate. Remove 2 blanking plate bolts and insert
timing tool LRT-12-044 into the larger bolt hole.
4.Engage timing tool pin with slot in flywheel.
5.Check correct alignment of timing mark on
camshaft gear and that crankshaft key aligns
with cast arrow on housing.
6.Insert pin from special tool LRT-12-045 in
injection pump gear and through into pump
flange.
NOTE: If the camshaft gear is to be
removed during these operations its
retaining bolt should be slackened before
the timing belt is removed.
7.Slacken belt tensioner bolt.
8.Remove idler pulley.
9.Remove timing belt.
NOTE: During use, a belt develops a wear
pattern relative to its running direction, if
the original belt is to be re-used it must be
refitted so that it rotates in the original direction.
CAUTION: Belts must be stored on edge
on a clean surface and in such a manner
that bends are not less than 50 mm radius.
Do not bend belts at an acute angle or radius of
less than 50 mm, otherwise premature failure
could result.
10.Mark belt direction of rotation, using soft chalk,
to ensure correct refitment.
12ENGINE
10
REPAIR TIMING CHAIN AND CHAINWHEELS
Service repair no - 12.65.12
Remove
1.Remove front cover.
See Front Cover Gasket
2.Remove retaining bolt and washer, remove
distributor drive gear and spacer.
3.Ensure number one piston is at TDC.
4.Remove chainwheels and chain as an assembly.
See V8i Overhaul Manual.
Refit
5.Clean chainwheels and chain.
6.Fit chainwheels to chain, aligning timing marks.
7.Ensure camshaft key is fitted parallel to shaft
axis to ensure adequate lubrication to distributor
drive gear.
8.Engage chainwheel assembly on camshaft and
crankshaft keys, ensure chain wheels are fully
located.
9.Check alignment of timing marks with straight
edge.
10.Fit spacer with flange to front,
11.Fit distributor drive gear with groove towards
spacer.
12.Fit retaining bolt and washer. Tighten to
58 Nm.
13.Fit front cover.See Front Cover Gasket
FLYWHEEL
Service repair no - 12.53.07
Remove
1.Remove gearbox and clutch.
See CLUTCH,
Repair, Clutch Assembly
2.Loosen starter motor bolts.
3.Lock flywheel, remove flywheel bolts and
flywheel.
Refit
4.Clean components for reassembly.
5.Fit flywheel.
6.Clean threads, apply Loctite 270 to threads.
7.Lock flywheel, fit flywheel bolts. Tighten to
80
Nm.
STEERING
1
DESCRIPTION AND OPERATION DESCRIPTION
The power assisted steering system incorporates a
compression joint in the lower shaft, designed to
collapse on impact and for certain countries, an air
bag located in the centre of the steering wheel.
The mis-alignment of the upper steering column with
the steering box and the inclusion of two universal
joints and a compression joint in the lower shaft, is
also designed to prevent frontal impact moving the
column toward the driver.
The steering box is located behind the first cross
member of the chassis and is connected to the road
wheels by the drag link and track rod. An hydraulic
damper absorbs shocks in the steering, caused by
road wheel deflections when operating on rough
terrain.Power steering system
The power steering system comprises a hydraulic
pump which is belt driven from the engine and
supplied with fluid from a reservoir that also acts as a
cooler.
The steering box houses a self neutralizing rotary
valve which is part of the worm/valve assy and a
hydraulic piston/rack to assist the mechanical
operation.
The rotary valve which is operated by movement of
the steering wheel, directs fluid pressure to the
appropriate side of the hydraulic piston/rack to provide
assistance.
Power steering system
1. Hydraulic pump
2. Fluid reservoir
3. Steering box
4. Upper column
5. Universal joints
6. Lower shaft
7. Compression joint
8. Drag link
STEERING
5
DESCRIPTION AND OPERATION Rotary valve operation
The rotary valve assembly seen in RR3620M
comprises the worm (1), the valve sleeve (2), the input
shaft (4) and the torsion bar (5).
The valve sleeve is retained inside the worm by the
trim screw (3), and incorporates valve ports in its inner
bore. The input shaft is attached to the steering wheel
via the steering shaft and steering column and
incorporates valve ports in its outer diameter to align
with those in the sleeve. The torsion bar which is
secured to the worm and input shaft with pins (6) at
each end (later models use one pin at input shaft
end), holds the valve ports in neutral alignment when
there is no demand for assistance.No demand for assistance (Valve at neutral)
When there is no demand for assistance as seen in
RR3620M, the torsion bar holds the input shaft and
sleeve valve ports in neutral relationship to one
another, allowing equal pump pressure A to both
sides of the piston/rack (9). Any excess fluid flow from
the pump returns to the reservoir via B.
Rotary valve at neutral
57STEERING
6
DESCRIPTION AND OPERATION Demand for assistance (Valve misaligned)
When the steering wheel and input shaft is turned,
steering resistance transmitted to the worm causes
the torsion bar to be twisted and the valve ports to be
misaligned for a right or left turn. The misalignment of
the valve ports directs all fluid pressure A to one side
of the piston only and allows displaced fluid B on the
other side.When demanding maximum assistance, any
excessive fluid output from the pump due to high
pump speed, will circulate through the regulator valve
located in the pump unit, causing the temperature of
the fluid and the pump to rise rapidly.
To avoid excessive fluid temperatures which could
damage the oil seals, the steering must not be held on
full lock for more that 30 seconds in one minute.
Only when the steering wheel and the demand for
assistance is released, will the torsion bar return the
valve to neutral, allowing the fluid to circulate through
the reservoir where it is cooled.
In the unlikely event of mechanical failure of the
torsion bar, a coarse splined connection (7) between
the input shaft and worm, ensures steering control is
maintained sufficient to allow the vehicle to be
recovered.
Rotary valve misaligned
57STEERING
4
FAULT DIAGNOSIS Symptom:-
Fluid leaks from steering box seals.
CAUTION: The steering wheel must not be
held on full lock for more than 30 seconds
in one minute, as this may overheat the
fluid and cause damage to the oil seals.
1.Check fluid level.
See Repair, Power Steering
Fluid Reservoir
Check fluid pressure.See Power Steering
System - Test
2.Is pressure high?
YES - Renew pump.
See Repair, Power
steering Pump
If oil seal leaks persist after renewing the
pump.
See Overhaul, Power Steering
Box
NO -See Overhaul, Power Steering Box
Symptom:-
Insufficient power assistance - castor return
action normal.
1.Are tyres correct type and pressure?
NO -
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres
YES - Continue.
2.Is fluid level correct?
NO - Check fluid level
See Repair, Power
Steering Fluid Reservoir
YES - Check system for air locks.See Repair,
Power Steering System - Bleed
3.Is pressure correct?
NO - Check fluid pressure.
See Power
Steering System - Test
If pressure is not correct after bleeding
the system, renew pump.
See Repair,
Power Steering Pump
YES -See Overhaul, Power Steering Box
Symptom:-
Steering heavy - stiff, poor castor return action.
1.Are tyres correct type and pressure?
NO -
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres
YES - Check universal joints for seizure and
correct alignment.
See Repair, Lower
Steering Shaft and Universal Joints
Check power steering box adjustments.
See Overhaul, Power Steering Box
2.Is the power assistance satisfactory?
NO - See fault symptomInsufficient
assistance, (castor return action
normal).
YES - Disconnect drag link from drop arm and
check steering column and box for
stiffness.
See Repair, Drag Link and
Drag Link Ends
3.Is the steering stiff with the drag link
disconnected?
NO - Check steering ball joints for seizure and
axle swivels lubrication and resistance.
See Repair, Drag Link and Drag Link
Ends See FRONT AXLE AND FINAL
DRIVE, Overhaul, Front Stub Axle,
Constant Velocity Joint and Swivel Pin
Housing Non ABS See FRONT AXLE
AND FINAL DRIVE, Overhaul, Front
Stub Axle, Constant Velocity Joint and
Swivel Pin Housing ABS
YES - Disconnect the lower steering shaft and
check the column and box for stiffness.
See Repair, Lower Steering Shaft and
Universal Joints
4.Is the steering column stiff to turn when
disconnected from the box?
NO - Remove and overhaul box.
See
Overhaul, Power Steering Box
YES - Adjust steering column.See Stiff
Steering Checklist
STEERING
5
FAULT DIAGNOSIS Symptom :-
Steering excessively light/sensitive. Excessive
freeplay at steering wheel.
1.Are steering box adjustments correct?
NO -
See Adjustment, Power Steering Box
WARNING: Adjustments of steering box
should not be required while in warranty
period. If box is within warranty, it must be
returned to manufacturer. No attempt must be
made to introduce backlash.
YES - Suspect worn panhard rod or radius arm
bushes Check condition of ball joints and
the lower steering column shaft universal
joints for wear.
See Repair, Lower
Steering Shaft and Universal Joints
Symptom :-
Steering vibration, road wheel shimmy - wobble.
Vibration through the steering linkage powerful
enough to induce high frequency oscillation of the
steering wheel, is generally caused by out of balance
road wheels. However there are a number of other
possible causes of this symptom which if severe, may
be described as shimmy or wobble. Regardless of the
terminology used by the owner/driver to describe the
symptoms, the following diagnostic checks should be
carried out in the order presented.
1.Check the tyres and balance of the road wheels.
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres See
WHEELS AND TYRES, Fault diagnosis, Fault
- Symptoms See WHEELS AND TYRES,
Repair, Wheel Balancing
2.Check the steering hydraulic damper function.
See Steering Damper
3.Check steering column universal joints for wear
and correct alignment.
See Repair, Lower
Steering Shaft and Universal Joints
4.Check steering linkage ball joints for wear,
correct alignment and security, including steering
box and tie rod.
See Steering Linkage Inspect
5.Check all front suspension rubbers for wear.
Check all fixing torques, including radius arm
bushes, panhard rod and anti-roll [sway] bar.
See FRONT SUSPENSION, Repair, Panhard
Rod See FRONT SUSPENSION, Repair,
Radius Arm See FRONT SUSPENSION,
Repair, Anti-Roll[Sway] Bar Assembly See
FRONT SUSPENSION, Repair, Front Shock
Absorber
6.Fit new radius arm bushes using NTC 6860. Fit
harmonic damper if vehicle has air suspension.
Fit new nuts, bolts and washers.
7. Coil spring vehicles only- If problem persists
fit damper kit STC 241 (2 off front) and STC
1474 (2 off rear). Road test vehicle.
8.Check the power steering box adjustments and
operation.
See Overhaul, Power Steering Box
9.Check the hub bearing end floats and determine
the condition of the hub bearings. As applicable.
See FRONT AXLE AND FINAL DRIVE, Repair,
Front Hub Assembly
10.Check the resistance and condition of the
swivels.
See FRONT AXLE AND FINAL
DRIVE, Description and operation,
Description
If problem is not diagnosed: Repeat
checks starting at 1.
11.Carry out a full steering geometry check.
See
INTRODUCTION, Information, Steering