1958 FIAT 500 Workshop Manual

to the body and proceed as follows:
1 If the camber angle requires to be increased (see FIG
8:16) add the same number of shims S on both
screws D and E.
2 If the camber angle requires to be reduced (see FIG
8:16) remove the same number of shims from both
screws D and E.
The addition or removal of shims at the t w o points D
and E permits camber adjustment to be made without
any disturbing of the castor angle.
8:10 Modifications
Checking and adjusting castor and camber angles:
When checking the castor and camber angle the
static loading should be such that the distance between
the semi-elliptic spring mountings G (see FIG 8:16)
and the floor level to be approximately 6.81 inches, also a
distance between the lowermost portion of the sump and
the floor level of approximately 6.14 inch for the Model
500D. For the 500 Station Wagon version the distance
between centre rear bracket for jacking-up the vehicle
and the floor level should be approximately 8.90 inches.
All other front wheel alignment specifications are the
same as for the remaining 500 saloon models.
8:11 Fault diagnosis
(a) Wheel bounce
1 Tyre casing faulty
2 Uneven tyre pressures
3 Wheels out of balance
4 Semi-elliptic mounting spring worn5 Weak or seized shock absorber
6 Wheel rim or tyre misaligned
(b) Suspension noise
1 Lack of lubrication
2 Noisy or inoperative shock absorbers
3 Worn or loose wheel bearings
(c) Pull to one side
1 Low or uneven tyre pressures
2 Incorrect front wheel alignment
3 Suspension arms distorted
4 Inoperative shock absorbers
5 Brakes binding
(d) Excessive t y r e wear
1 Incorrect tyre rotation during servicing periods
2 Incorrect camber angle
3 Incorrect toe-in
4 Incorrect tyre inflation
5 Excessive play at wheel bearings
6 Wheel wobble
7 Stiff suspension arms
8 Brakes out of adjustment
(e) Wheel wobble
1 Uneven tyre pressures
2 Loose or worn wheel bearings
3 Inoperative shock absorbers
4 Loose steering knuckle or kingpin housing
5 Incorrect front wheel alignment
6 Control arm rubber bushings, or kingpin housing and
semi-elliptic spring 'estendblock' worn
96

CHAPTER 9
THE STEERING SYSTEM
9 : 5 Relay lever and support
9 : 6 Steering rods
9 : 7 Front wheel toe-in
9 : 8 Fault diagnosis 9:1 Description
9 : 2 Steering wheel removal and refitting
9 : 3 Steering box removal and refitting
9 : 4 Steering box dismantling and reassembly
9:1 Description
The steering gear fitted to the new 500 range of
vehicles is of the worm screw and sector type with a
steering ratio of 1:13. The steering gearbox is located on
the front lefthand side of the dash wall on the scuttle as
shown in FIG 9:1. The steering gear comprises a pitman
arm and relay lever pivoting on a pin supported on the
body. A central track rod connects the pitman arm to the
relay lever. T w o track rods connect the pitman arm and
relay lever to the knuckle arms.
9:2 Steering wheel removal and refitting
To remove the steering wheel proceed as follows:
1 Disconnect the battery positive terminal clamp and
remove the horn control from the steering wheel.
2 Remove the cable from the push button seating and the
cable insulation sleeve.
3 Using a suitably sized box spanner or Fiat wrench
A.8279 unscrew the steering wheel to shaft nut as
shown in FIG 9:2.
4 Using the palm of the hands against the back of the
steering wheel rim gently tap the steering wheel
forwards so releasing it from the inner shaft.
F50097 5 Reassembly is the reverse procedure to dismantling.
Care should be taken to ensure that the front wheels
are located in the straight ahead position when the
steering wheel is being replaced otherwise the steering
wheel spokes will not be correctly positioned.
9 : 3 Steering box removal and refitting
To remove the steering box from the vehicle proceed
as follows:
1 From inside the vehicle remove the steering column
clamp bolt 6 (see FIG 9 : 3) after flattening the lock-
washer 7.
2 From the underside of the vehicle remove the t w o
tie rod locking nuts from the pitman arm and then using
Fiat tool A.46006 or a suitable t w o leg puller withdraw
the pins from the seats.
3 Remove the three nuts holding the steering box to the
body panel. Ease out the worm screw from the
steering shaft and lift away the steering box.
4 To refit the steering box is the reverse procedure to
dismantling. The steering box to body mounting nuts
should be tightened to a torque wrench setting of
14 Ib/ft to 18 Ib/ft.

RIGHT HAND TIE ROD
RELAY LEVER SUPPORTINTERMEDIATE TIE ROD!
STEERING BOX!
LEFT HAND TIE ROD
FIG 9 :1 Steering box, idler member and steering linkage arrangement on vehicle
FIG 9 : 2 Securing steering wheel mounting nut
Key
to Fig 9:2(Tightening torque: 29 to 36 Ib ft)
9 : 4 Steering box dismantling and reassembly
1 Remove the steering gear housing cover complete
with the adjusting screw and locking nut and drain the
oil from the unit.
2 Using Fiat puller A.4005.1.5 or a universal t w o leg
puller remove the pitman arm.
3 Remove the cotter pin from the lower thrust bearing
adjusting nut and unscrew this nut.
4 Remove the sealing ring at the sector shaft lower end
and using Fiat tool A.8065 loosen the eccentric bush
adjuster plate bolt and remove both the bolt and the
adjusting plate. Also remove the upper sealing ring.
98
5 Lift out the sector together with the upper thrust
washer and shims.
6 Remove the steering worm screw by pulling out from
below. The two bearing inner rings will remain on the
worm screw whilst the lower bearing outer ring will
remain in the housing.
7 Remove the oil seal using Fiat tool A.10110 followed
by the worm screw upper bearing outer ring using
Fiat tool A.66040 or a suitably sized drift.
Inspection:
1 Carefully inspect the sector teeth and the worm screw
threads to see that there are no signs of seizure,
indentations or scoring. Check that the contact faces
indicate that meshing between the two parts is taking
place at the centre.
2 Check the clearance between the eccentric bush 5
(see FIG 9 : 5) and the worm sector 11 which must not
exceed .0039 inch. These items have an initial
assembly clearance of .00 to .0016 inch. It should be
noted that if the eccentric bushing to sector shaft
clearance exceeds .0039 inch a new bushing should
be installed and its inner face reamed using Fiat
reamer U.0360.20.
3 Ensure that the worm screw is not distorted. The
permissible out of true is .0019 inch.
Adjustment:
1 If the backlash between the worm screw and the
sector is excessive it should be adjusted by first dis-
connecting the pitman arm and its relevant seal.
Remove the screw 7 (see FIG 9 : 5) fixing the abut-
ment plate 6. Rotate the eccentric bush 5 by the
adjustment plate and move the sector in towards the
worm screw. The adjustment plate should be secured
again using the second fixing hole.
Should the adjustment plate already be fixed in the
second hole remove the plate from the bush and
rotate one or more serrations and re-secure.

FIG 9 : 3 Layout of steering gear components
Key to Fig 9 : 3 1 Steering wheel and column assembly 2 Nut 3 Toothed washer 4 Plain washer
5 Steering column bracket-to-instrument panel screw 6 Steering column-to-worm screw locking screw 7 Lockplate
8 Plain washer 9 Cover screw 10 Toothed washer 11 Cover 12 Gasket 13 Pin 14Nut 15 Plain washer
16 Worm sector adjusting screw 17 Worm sector and shaft assembly 18 Worm screw 19 Thrust washer 20 Shim
21 Splitpin 22 Lower sleeve, bearing retainer and worm screw adjuster 23 Roller bearing 24 Worm screw bearing
upper seal 25 Roller bearing 26 Steering gear housing 27 Oil filling and draining plug 28 Eccentric bushing
29 Upper seal 30 Worm screw-to-sector lash adjusting plate 31 Toothed washer 32 Plate screw 33 Lower seal
34 Pitman arm 35 Self-locking nut Inset: Universally-jointed column fitted from late 1971
99F500

FIG 9 : 4 Section of steering box, through worm screw
Key to Fig 9 : 4 1 Worm screw 2 Seal 3 Roller bearing
4 Worm screw adjuster and bearing retainer 5 Pitman arm
6 Worm sector
FIG 9 : 6 Steering box cutaway
100FIG 9:5 Section of steering box, through worm sector
Key to Fig 9 : 5 1 Sector adjustment screw 2 Locking
nut and plain washer 3 Sector thrust washer 4 Shim
5 Eccentric bush 6 Bush adjusting plate 7 Plate screw
and toothed washer 8 Pitman arm 9 Sector lower seal
10 Upper seal 11 Worm sector 12 Worm screw
13 Oil filler and level plug
2 If play is excessive in the worm screw rollers, screw up
the lower adjuster ring 4 (see FIG 9 : 4) . Once adjust-
ment has been completed the adjuster ring must be
secured by the cotter. The ring should be positioned
so that the hole in the steering box lines up w i t h one
of the spaces between the ring castellations.
3 Should the meshing between the worm screw and the
sector not be at the correct central position this
condition may be rectified by moving the sector
axially. To do this add or remove shims (see FIG 9 :5)
below the thrust ring of the worm sector. The final
adjustment must be carried out by using the adjust-
ment screw 1 (see FIG 9 : 5) on the cover and then
locking the screw by nuts 2. In service shims are
supplied .0039 inch thick.
The above described adjustments must eliminate
any play and back lash in the steering gear without
rendering the steering gear stiff to operate between
the t w o locks.
4 During adjustment should any seal be found to be
damaged then it should be renewed.
Reassembly:
Reassembly is the reverse procedure to dismantling
but the following points should be noted:
1 All parts should be thoroughly cleaned before

reassembling and during assembly liberally lubricated
using Fiat W90/M oil (SAE90 EP).
2 The pitman arm nut should be correctly positioned on
reassembly to the sector shaft and both are marked
with notches or a master tooth on the sector will mate
with a double tooth on the pitman arm which will
prevent incorrect reassembly.
3 The pitman arm nut must be tightened to a torque
wrench setting of 72 Ib/ft.
4 Fill the box up to the level and filler plug with SAE90 EP
gear oil.
Refitting the steering box:
To refit the steering box to the vehicle proceed as
follows:
1 Engage the w o r m screw f r o m the steering shaft by
gently manipulating the steering box.
2 Replace the steering box to body nuts and tighten to a
torque wrench setting of 14 to 18 Ib/ft.
3 Replace the t w o track rod pins in their seatings in the
pitman arm and tighten the self-locking nuts to a
torque wrench setting of 18 to 21 Ib/ft.
4 Replace the steering shaft to worm screw mounting
bolt, lock washer and nut.
9 :5 Relay lever and support
The steering idler arm is secured to the body by means
of a support bracket and a rubber bushed pivot bolt. This
is shown in FIG 9 : 7. When this unit is being serviced
the following points should be noted.
1 If there is excessive play between the pin and the
bushes the bushes must be renewed. Also check the
condition of the pin and if there are signs of excessive
wear it must be renewed.
2 To eliminate torsional stresses in the rubber bushes
during assembly the pin nut must be tightened to
torque wrench setting of 39 to 43 Ib/ft, once the
front wheel toe-in has been correctly adjusted w i t h the
wheels set in the straight ahead position.
3 The relay lever support to body mounting nuts must
be tightened to a torque wrench setting of 14 to 18
Ib/ft.
9 : 6 Steering rods (tie rods)
The steering rod is connected to the idler arm and the
drop arm by means of non-adjustable ball joints. The
track rods are connected to the right and left steering
arms by non-adjustable ball joints and comprise t w o
sleeves which are split and having internally threaded
ends. The ball joints are clamped to either end of the
sleeves. To facilitate adjustment one ball joint end has a
lefthand thread and the other a righthand thread.
Adjustment is made by loosening both the clamping bolts
and turning the central sleeve.
To remove the steering rods from the pitman arm, the
relay lever and knuckle arms Fiat pullers A.46006 and
A.6473 or universal ball joint removers should be used.
If excessive play is evident in the ball joint linkage or
the pin is damaged the complete ball joint assembly must
be renewed.
Upon reassembly the tie rod to ball pin knuckle arm
nuts must be tightened to a torque wrench setting of
18 to 21 Ib/ft.
F500101
FIG 9:7 Relay lever support section
FIG 9:8 Front wheel toe-in checking diagram
Key to Fig 9:8 A—B = 000 inch to .079 inch
It is important that all steering linkages are thoroughly
checked at regular intervals and if any parts are suspect
then they must be renewed.
9 : 7 Front wheel toe-in
To check and adjust the front wheel toe-in proceed as
follows:
1 Ensure that the tyres are inflated to the recommended
pressures. Ensure that the steering wheel is in its

normal straight-ahead position with the spokes
horizontal. Check that the wheels are in the straight-
ahead position.
2 Load the vehicle to static load conditions or with four
average size passengers.
3 Move the vehicle forwards for a distance of approxi-
mately six yards so that the suspension may settle
correctly.
4 The toe-in measurements should be taken at the same
point of the wheel rim. Measure at A (see FIG 9 : 8)
then back up the car to bring points A to the position B
and remeasure. The value obtained at A should be
equal to or greater than B within .0079 inch.
5 As previously described the steering rods are adjust-
able in length. Loosen the clamps and screw in or out
the adjusting sleeves and before tightening the clamp
ensure that the sleeve slot registers w i t h the clamp
joint. With the clamp fully tightened there should
always be a gap between the joint faces.
6 If the steering gear has been re-installed the correct
front wheel toe-in must be set. Then the relay lever pin
nut must be tightened to a torque wrench setting of 78
to 85 Ib/ft.
9 : 8 Fault diagnosis
(a) Front wheel shimmy
1 Incorrect tyre pressure
2 Incorrect front wheel alignment
3 Loose front wheel bearings
4 Wheels out of balance
5 Loose steering linkage connections
6 Loose steering gear or relay lever support at body
mountings
7 Incorrect fitting of steering worm to worm sector
(b) Hard steering
1 Incorrect tyre pressure
2 Incorrect front wheel alignment
3 Incorrect adjustment of steering worm to worm sector
(c) Hard turning when stationary
1 Incorrect tyre pressure
2 Incorrect adjustment of steering worm to worm sector
102
(d) Pull to one side
1 Incorrect tyre pressure
2 Incorrect front wheel alignment
3 Incorrect front wheel bearing adjustment
4 Distorted kingpin housing or swinging arms
5 Unequal brake adjustment
6 Semi-elliptic spring weak or broken
(e) Rattles
1 Loose steering linkage connections
2 Loose steering gear or relay lever support at body
mountings
3 Semi-elliptic spring weak or broken
4 Lack of lubrication
( f ) Loose steering
1 Incorrect front wheel bearing adjustment
2 Loose steering linkage connections
3 Loose steering gear mountings
4 Incorrect adjustment of steering worm to worm sector
(g) Jerky steering
1 Incorrect front wheel alignment
2 Incorrect front wheel bearing adjustment
3 Wheels out of balance
4 Loose steering linkage connections
5 Loose or incorrect fitting of worm to sector
(h) Side-to-side wander
1 Incorrect tyre pressure
2 Incorrect front wheel alignment
3 Loose steering linkage connections
4 Loose steering gear or relay lever support at body
mountings
5 Incorrect fitting of steering worm to worm sector
6 Distorted kingpin housing or swinging arm
7 Semi-elliptic spring weak or broken
(i) Tyre squeal on turns
1 Incorrect tyre pressure
2 Incorrect wheel alignment
3 Distorted kingpin housing or swinging arms

CHAPTER 10
THE BRAKING SYSTEM
10:1 Description
10:2 Maintenance
10:3 Front brakes
10:4 Rear brakes
10:5 Master cylinder
10:6 Wheel cylinder10:7 Self-adjusting device
10:8 Removing a flexible hose
10:9 Brake fluid reservoir
10:10 Bleeding the system
10:11 Hand parking brake
10:12 Fault diagnosis
10:1 Description
All four drum brake units are hydraulically operated by
the brake pedal and the handbrake lever operates the rear
brakes only through a mechanical linkage which normally
requires no separate adjustment (see FIG 10:1).
The brake units are of the internal expanding type with
one leading and one trailing shoe to each brake. A double
ended wheel cylinder expands both shoes into contact
with the drum under hydraulic pressure from the master
cylinder. When the brake pedal pressure is released the
shoes are retracted by means of springs.
The brake pedal is directly coupled to the hydraulic
master cylinder where pressure on the fluid is generated.
This is transmitted to the brakes by a system of metal and
flexible pipes.
The braking units fitted to the new 500 Sedan models
are equipped with a specially designed brake shoe
clearance self-adjustment device which eliminates the
need for manual adjustment of the brake shoe to drum
clearance as is normal practice w i t h a conventional
braking system. Every time the brake pedal is depressed
the self-adjustment device automatically takes up the
excess clearance which may have developed between
the lining and the drum due to normal service wear.
The brake units fitted to the 500 Station wagon model
have a normal brake adjuster which should be used when
F500103 the brake pedal travel becomes excessive. The adjuster
is shown in FIG 10:3.
On later models a dual circuit system is used. It is
described in Section 10:12
10:2 Maintenance
Brake adjustment {Station Wagon)
Jack each wheel in turn after first chocking the remain-
ing three wheels and releasing the handbrake. Depress
the brake pedal so as to force the brake shoes against the
drum and keeping the shoes in this position turn the
adjuster nuts until they contact the shoes and then back
the nuts 20 deg. This will correctly set the shoe to drum
clearance which should be checked for binding by
releasing the brake pedal and ensuring that the road wheel
revolves freely. The operation should then be repeated
on the other wheels. This adjustment will automatically
set the handbrake.
Preventative maintenance:
1 Thoroughly inspect the metal hydraulic fluid lines for
rusting, cracking or flattening and that they are
located away from any sharp edges which could cause
a failure.