Defender 90 NAS. Manual — part 51
FRONT AXLE AND FINAL DRIVE
1
SPECIFICATIONS, TORQUE
TORQUE VALUES
FRONT AXLE
Nm
. . . . . . . . . . . . . . . . ..
lbf/ft
Hub driving member to hub
65*
. . . . . . . . . . . ..
48*
Brake disc to hub
73
. . . . . . . . . . . . . . . .
55
Stub axle to swivel pin housing
65*
. . . . . . . . . .
50*
Brake caliper to swivel pin housing
82
. . . . . . . . ..
60
Upper swivel pin to swivel pin housing
65*
. . . . . . . .
48*
Lower swivel pin to swivel pin housing
25*
. . . . . . . .
18*
Oil seal retainer to swivel pin housing
11
. . . . . . . ..
8
Swivel bearing housing to axle case
73*
. . . . . . . .
55*
Differential drive flange to propeller shaft
47
. . . . . . .
35
Mudshield to bracket lower swivel pin
11
. . . . . . . ..
8
Bevel pinion nut
130
. . . . . . . . . . . . . . . .
95
Draglink to swivel pin arm
40
. . . . . . . . . . . .
30
Panhard rod to axle bracket
88
. . . . . . . . . . . .
65
Radius arm to axle bracket
190
. . . . . . . . . . . ..
140
Radius arm to chassis side member
190
. . . . . . . .
140
Track rod end
40
. . . . . . . . . . . . . . . . ...
30
Hub adjusting nut
50
. . . . . . . . . . . . . . . .
37
Road wheel nuts
130
. . . . . . . . . . . . . . . ..
95
NOTE: * These bolts to be coated with Loctite 270 prior to assembly.
STEERING
1
DESCRIPTION AND OPERATION
DESCRIPTION
The steering system incorporates a compression joint
in the lower shaft and is designed to collapse on
impact. The misalignment of the upper steering
column with the steering box and the inclusion of two
universal joints, is also designed to prevent the
column moving towards the driver under frontal
impact.
The steering box is located behind the first chassis
cross member and is connected to the road wheel
swivel housing by a 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 an 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 an
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
57
STEERING
2
DESCRIPTION AND OPERATION
Power steering box components
1. Housing complete with sector shaft bearings
2. Cover plate complete with bearing
3. Sector shaft
4. Hydraulic piston/rack
5. Worm/valve and torsion bar assembly
6. Shims for centralizing worm/valve
7. Ball race - 2 off
8. ’Teflon’ seals for valve sleeve - 3 off
9. Bearing adjuster, locknut and seal
10. Worm shaft pressure seal, circlip and dirt
excluder
11. ’Teflon’ and rubber seal for piston
12. End cover seal and snap ring
13. Adjustment components for piston/rack
14. Hydraulic pipe
15. Bleed screw
16. Sector shaft adjustment lock nut with seal
17. Cover plate bolts - 4 off
18. Cover plate seal
19. Seal, washer and backup seal
20. Circlip and dust cover
STEERING
3
DESCRIPTION AND OPERATION
Rotary valve operation
The rotary valve assembly comprises a worm (1),
valve sleeve (2), input shaft (4) and torsion bar (5).
The valve sleeve is retained inside the worm by a trim
screw (3), and incorporates valve ports in its inner
bore. The input shaft is attached to the steering wheel
via a 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 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, 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
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст