1971 FIAT 500 mount

TOOL A 62039
TOOLA. 62040 PIN WRENCH A. 52022
FIG 6:15 Adjusting ring gear-to-pinion backlash and
differential bearing play, using special wrench A.52022
reading on the dial gauge should be between .0031 to
.0047 inch. The actual clearance is adjusted by
screwing in one adjusting nut and screwing out the
other by the equivalent amount using Fiat spanner
A.52022 as shown in FIG 6:15.
4 Remove Fiat tool A.62041 and using Fiat support
A.62040 mount the special dynamometer A.95697 and
adaptor on the axle shaft. Rotate the axle shaft several
turns so seating the bearings and then check using
the dynamometer the rotation torque.
5 If necessary tighten or slacken the adjusters until the
specified torque of 1.01 ± .07 lb ft is obtained. This
operation must be very carefully carried out because if
one adjuster is set differently with respect to the other,
a variation in ring gear to pinion backlash may take
place, resulting in a variation of rotation torque. After
any adjustments always recheck on the ring gear to
pinion backlash and if necessary readjust and then
repeat the rotation torque check.
6 Finally check the tooth contact between the pinion
and ring gear as detailed in the following instructions:
Check and adjustment of tooth contact between
pinion and ring gear:
1 Carefully apply to the ring gear teeth a thin layer of
engineers' blue and gently rotate the differential whilst
holding the axle shaft firmly but allowing them to slip
slightly so as to have the unit working under load
conditions.
2 A contact impression will be left on the ring gear teeth
and the contact will be correct when the drive pinion
tooth contact pattern is evenly distributed on the ring
gear teeth as shown in FIG 6:16. Should the tooth
contact be incorrect the following observations should
be noted.
Excessive contact on tooth flank. Too deep
meshing — move pinion out from ring gear by reducing
thickness of shim.
Excessive contact on tooth heel. Too slight
meshing—move pinion in towards ring gear by
increasing thickness of shim.
74
6 : 8 Replacement of gearbox—differential unit
Installation is the reverse procedure to removal of the
unit from the vehicle as described in Section 6:2.
However, the following points should be noted:
1 Ensure that the clutch driven disc hub is correctly
aligned with the clutch shaft pilot bush.
2 The complete transmission unit should be carefully
pushed towards the engine and the clutch shaft
inserted into the driven disc hub splines and finally
home into the pilot bush. Extreme care must be taken
to ensure that no weight is placed on the clutch shaft
otherwise distortion may take place.
3 Carefully connect the gearbox rear housing to the
engine crankcase by using the studs, t w o of which
have special location dowels fitted. Screw home
finger tight the gearbox/differential to body to front
support mounting screws inserting the fibre washers.
Lower the hydraulic garage jack and pull it away from
underneath the vehicle. Screw in the four lower
mounting nuts and tighten to a torque wrench setting
of between 18.1 to 21.7 Ib f t.Finally tighten the front
support screws.
4 Reconnect the gear shift control rod and the speedo-
meter drive cable. Insert the springs between the axle
shafts and wheel drive shaft and tighten the
three
mounting screws of each splined sleeve on the
flexible joint to a torque wrench setting of 20.3 Ib ft.
5 Refit the flywheel housing cover. Replace the starter
motor together with its relevant cover and tighten the
two mounting nuts to a torque wrench setting of
18.1 to 21.7 Ib ft. Reconnect the starter control rod,
the t w o starter cables, the clutch control tie rod and
hook up the return spring and secure the clutch
control cable retainer bracket to the gearbox casings.
Reconnect the cable to the battery positive terminal
post
6 Lower the vehicle to the floor gently and then give a
thorough road testing.
6 :9 Swing axle shafts and slip joints
Description:
The t w o axle shafts are connected to the differential
unit through specially designed slip joints which allow
the shafts to swing and slide in the splined housing in
the differential side gear. At the other end, the axle shafts
are connected to the wheel drive shaft flexible joints
using a sliding sleeve. Excessive contact on tooth face. Too slight
meshing—move pinion in towards ring gear by in-
creasing thickness of shim.
Excessive contact of tooth toe. Too deep meshing
—move pinion out from ring gear by reducing thickness
of shim.
With all the above detailed cases, to adjust the pinion
by replacing the shim, the differential unit and drive
pinion shaft must be dismantled. This means that when
the unit is reassembled after the necessary adjustments
have been made, the backlash and bearing rotation
torque must be repeated.

LEVER SUPPORT SCREWS BOOT MOUNTING SCREWSGEARSHIFT LEVER BOOT
GEARSHIFT LEVER
FIG 6:17 Location of gearshift lever on control passage
tunnel
Repair and inspection :
Whilst servicing the assembly thoroughly check the
condition of the slip joints sliding surfaces and the
housing in the differential side gears. If, due to wear, the
clearance is greater than .008 inch the slip joints should
be renewed or in extreme cases the differential side gears
as well.
Also check the clearance between the slip joint pivots
and runners and if it is found to be excessive the axle
shafts must be renewed as well as the runners as the
joint pivot is not supplied as a service spare part. The axle
shaft to sliding sleeve spline clearance should not exceed
.006 inch.
Check that the sliding sleeve snap ring is a snug fit in
its seating groove on the shaft.
Whenever the vehicle is being serviced the condition
of the boots, bushings and oil seals should be checked
and any damaged parts renewed.
6:10 Gear shift control mechanism
Should difficulty be experienced in obtaining correct
gear selection then the gear shift control mechanism
should be adjusted as follows:
1 Remove the screws fixing the cover to the tunnel and
raise t h e cover to t h e t o p of the gear shift lever stem.
2 Slacken the lever support mounting screws and push
the support forward if first- and third-speed engage-
ment is incorrect or backwards if second-, fourth- and
reverse-speed engagement are incorrect. Finally tighten
the mounting screws. Refit the gear shift lever boot.
Removal:
To remove the gear shift control mechanism from the
car proceed as follows:
1 Unscrew the gear shift control lever knob and the boot
fixing screws and slide the boot from the gear shift
lever.
76Key to Fig 6:18 1 Hand lever 2 Inner lever
3 Lever return spring 4 Hand lever spring 5 Ball seat
6 Inner lever-to-rod mounting screw 7 Gearshift control rod FIG 6:18 Gearshift control mechanism
6:11 Modifications
Various design modifications are incorporated on the
500 sedan (110F) and the late version of the 500 station
wagon. These are shown in FIGS 6:19 and 6:20, The gear shift handlever is removed by releasing the
lever to support mounting self-locking nut.
Check that the lever ball and socket are in good
condition and not badly pitted or worn. The inner lever
return spring and the hand lever spring should be checked
for weakness which, if apparent, should be renewed.
Reassembly is the reverse procedure to dismantling. Dismantling and inspection: 2 Remove the screws fixing the assembly to the tunnel.
Remove the tunnel front cover.
3 Disconnect the gear shift control rod at the gear
engagement control lever and pull out the assembly
from the front end.

although these do not affect the service procedures that
have been previously described.
6:12 Fault diagnosis
(a) Noisy transmission
1 Excessive backlash of gears in mesh due to gear wear
2 Gears, bearings or gear bushings damaged
3 Shafts misaligned or out of centre due to loose mount-
ing nuts
4 Dirt or metal chips in the lubricant
5 Insufficient oil level in transmission case
(b) Transmission jumps out of gear or gear
shifting is irregular
1 Improper shifting
2 Gear shift lever mounting bracket out of adjustment
3 Incorrect assembly or damage of striker rod positioning
balls and springs
4 Striker rod rollers worn or assembled incorrectly
(c) Oil leakage
1 Overfilled transmission case2 Front extension, upper cover and clutch housing nutsloose
3 Speed selector and engagement lever seal at front
extension damaged
4 Faulty bellhousing gasket
5 Gaskets, upper cover-to-case, front extension-to-case,
damaged
6 Damaged axle shaft boot or seal
(d) Transmission shifts hard
1 Defective link of gear shift lever to internal front lever
2 Internal front lever rubber bushing and plates damaged
3 Speed selector and engagement lever control rod
twisted
4 Control rod-to-speed selector and engagement lever
joint damaged
5 Speed selector and engagement lever worn
6 Striker rods binding in casing
7 Sliding sleeves and gears bound in their seats due to
the presence of dirt in splines
8 Improper quality of transmission lubricant
9 Misadjusted clutch linkage and clutch make de-
clutching impossible
78

CHAPTER 7
REAR SUSPENSION AND WHEELS
7:1
7:2
7:3
7:4Description
Removal of rear suspension assembly
Servicing swinging arms
Coil springs
7:1 Description
The rear wheels are independently sprung by means of
coil springs and V-shaped swinging arms acting on coil
springs and telescopic double acting hydraulic shock
absorbers. The swinging arms are m o u n t e d at their inner
ends on 'estendblocks', the coil spring is fitted at the outer
end of the swinging arm. At the wheel end of the suspen-
sion arm is attached a steel pressing to which the brake
backplate and wheel bearing housing are bolted so
forming a swinging unit to which is attached the road
wheel.
The inner pivots are so located vertical wheel move-
ments do not influence the drive shaft length which
means that there is no need to fit a splined joint at the
wheel end. Two taper roller bearings which are separated
by a specially designed collapsible spacer are located in
the rear wheel bearing housing and this carries the axle
shaft. The outer end of the axle shaft is flanged and it
is to this flange that the brake drum is bolted. The splined
inner end carries a rubber cushioned coupling to which
the drive shaft flange is attached.
7 : 2 Removal of rear suspension assembly
1 Jack-up the vehicle and place on firmly based stands.
Remove the road wheel on the side from which the
suspension unit is to be removed.
F50079 7:5
7:6
7:7
7:8Installation of rear suspension assembly
Checking and adjusting rear wheel toe-in
Modifications
Fault diagnosis
2 Using a garage hydraulic jack support the swinging
arm to facilitate the removal of the upper shock
absorber mounting nut which is located inside the
vehicle on the floor. To gain access to the nut remove
the rear wheel housing linings.
3 Unhook the parking brake shoe control lever return
spring.
4 Remove the three screws securing the drive shaft
flange to the flexible coupling. Pull back the sleeve and
remove the inner spring.
5 Remove the brake fluid reservoir cap, remove the filter
and plug the delivery hole in the brake f l u i d reservoir
and disconnect the flexible brake pipe from the
bracket on the body floor.
6 Disconnect the parking brake control tie rod by first
removing the cotter pin and removing the cable eye
from the pin on the shoe control lever. Release the
cable adjustment nuts and free the cable from the
fairlead on the swinging arm.
7 Using the hydraulic jack carefully lower the swinging
arm, fully retract the shock absorber by pushing in the
outer cylinder and carefully pull out the coil spring
together with its mounting rubber rings.
8 Remove the self-locking nut securing the swinging
arm to the internal support welded on the floor.
Extract the mounting pin and note the number and
arrangement of shims between the bushings and the
bracket. This will facilitate reassembly.

FIG 7 : 1 Rear suspension assembly
Key to Fig 7 : 1 1 Brake shoe control cable and sheath 2 Coil spring 3 Oil boot 4 Axle shaft 5 Bumper
6 Flexible joint 7 Swinging arm 8 Cable adjusting nut 9 Swinging arm-to-front bracket mounting pin
10 Swinging arm front bracket-to-underbody mounting screw 11 Engine front support crossmember 12 Swinging arm
rear self-locking nut 13 Shock absorber-to-swinging arm lower nut 14 Sleeve screws 15 Axle shaft-to-flexible joint sleeve
9 Remove the three swinging external support fixing
bolts securing the outer suspension arm bracket to the
vehicle floor and remove the rear suspension assembly.
Remove the special rubber pad located between the
support bracket and the vehicle floor.
7 : 3 Servicing swing arms
Dismantling:
1 Remove the cotter pin and release the nut fixing the
flexible joint to the wheel shaft. Remove the plain
washer and the joint.
2 Using Fiat tool A.40005.1.9 or a universal two-leg
puller, remove the wheel shaft and brake drum.
Extract the t w o oil seals and both the outer and inner
bearing inner rings, thrust ring of the joint and the
resilient spacer.
3 Using Fiat tool A.6511, remove the t w o bearing outer
rings.
4 Disconnect the brake hydraulic line at the wheel
cylinder and remove the swinging external support.
The bearing housing and brake housing flange may
then be removed.
Inspection :
Thoroughly clean all the parts and install the swinging
arm on Fiat fixture A.66064 as shown in FIG 7 : 4. If the
80
swinging arm has not been distorted its installation on the
fixture should be straightforward. Tighten the clamp
screws 1 (see FIG 7 : 3) on the road wheel brake drum,
connect the swinging arm inner member to the seating
2 on the fixture and finally fit the swinging arm external
support holes on the fixture pins 3. Should difficulty be
experienced in either one of these three operations then
this is an indication that the swinging arm is distorted and
should be straightened or a new assembly fitted. If this
check is satisfactory proceed as follows:
1 Check that the 'estendblocks' are a snug fit in their
respective seatings in the swinging arm and that the
mounting pin slides in freely w it h ou t excessive play.
To renew the 'estendblocks' use Fiat tool A.66056
which is suitable for both their removal and installation.
2 Check that the inner and outer bearing outer rings have
no play in their seatings and that the rollers and cages
are not broken, cracked, show signs of overheating
or are worn.
3 Ensure t h a t the o i l seals f i t snugly on the wheel shaft,
also on the joint spacer or shoulder ring and on the
hub seats. If the oil seals should show any signs of wear
then these should be renewed.
4 Inspect the resilient spacer for signs of hair line cracks,
which if not evident the spacer may be used again as
it is not permanently distorted during assembly.
Should, however, new bearings or bearing housings
be fitted it is considered good practice to fit a new
spacer.

FIG 7 :2 Right rear suspension assembly, sectioned through brake drum and arm mountings
5 Check the mating surface of the bearing inner rings on
the wheel shaft and ensure that it is perfectly smooth.
Also check that the shaft splines to flexible joint
splines are not distorted or show signs of excess wear.
The maximum permissible wear backlash is .0059 inch.
6 Ensure that the f l e xible joint is not damaged where the
rubber is bonded to the metal. If signs of strain are
indicated a new joint must be fitted.
F50081
Reassembly:
Reassembly of the swinging arm unit is the reverse
procedure to dismantling. The following points should
be noted:
1 Always use Fiat tool A.66056 to install 'estendblock'
on the swing arm.
2 The mounting nuts for the bearing housing to the
brake housing flange should always be tightened to a

high bearing preload. To reset remove the wheel shaft
and fit a new resilient spacer. Repeat the rotation
torque test.
Swinging arm adjustment:
To adjust the swinging arm use Fiat fixture A.66064 as
shown in FIG 7 : 3 and proceed as follows:
1 At points A and B as indicated in FIG 7 : 4 between the
'estendblock' and the swinging arm to body front
mounting bracket fit three shims on each side. To
ensure that the shims are correctly centred use Fiat
alignment bar A.66057.
2 Whilst removing the alignment bar, carefully slip in the
mounting pin and screw on the nut. Once the rear
wheel geometry adjustment has been completed this
nut should be tightened to a torque wrench setting
of 43.4 to 50.6 Ib ft.
3 At points C and D (see FIG 7 : 4) , insert the number of
shims required to fill in the gap between the 'estend-
block' and the two fixture shoulders. Having deter-
mined the number of shims required both at locations
C and D, these must later be fitted between the
'estendblock' and the shoulders on the swinging arm
to body mounting bracket.
7 : 4 Coil springs
The coil springs should be thoroughly cleaned and all
traces of rust removed. Inspect the spring coils for hair
line cracks, which if evident, a new pair of springs must
be fitted to ensure correct vehicle height and stability.
Check the free
height and the height under loading of
the coil springs and these must correspond to the figures
quoted in Technical Data.
7:5 Installation of rear suspension assembly
To replace the rear suspension assembly proceed as
follows:
1 Insert the swinging arm inner end in the mounting
bracket which is welded onto the body floor. Place
between the 'estendblock' and bracket the number of
adjustment shims as previously determined using Fiat
fixture A.66064 as shown in FIG 7 : 4. Insert the Fiat
alignment bar A.66057 through 'estendblock' and
shims, aligning them with the holes in the mounting
bracket. Firmly hold the entire assembly using a garage
hydraulic jack if necessary, and carefully remove the
alignment bar and at the same time ease in t h e
mounting pin. Secure the nut which once the rear
wheels geometry has been checked must be tightened
to a torque wrench setting of 43.4 to 50.6 Ib/ft.
2 Screw in finger tight the three swinging arm external
bracket to body floor mounting screws together w i t h
the plain and spring washers. The screws will have to
be tightened to a torque wrench setting of 28.9 to
36.2 Ib/ft once the rear wheel geometry has been
adjusted.
3 Carefully insert the coil spring, lower insulator ring
onto the swinging arm, insert the spring on the shock
absorber which should be previously secured to the
arm and position the spring onto its seat on the arm.
Place the upper insulator ring onto the spring, raise the
suspension assembly using a garage hydraulic jack and
insert the spring onto its seating under the body floor.
F50083 4 Ensure that the shock absorber to floor rubber ring has
been correctly fitted and extend the shock absorber
until its upper mounting pin protrudes into the vehicle
through the hump in the floor panel. Secure the shock
absorber by its mounting nut and lockwasher having
first inserted the rubber ring and plain washer.
5 Refit the rear wheel housing in place, reconnect the
brake line to the connection on body floor and remove
the plug from the output hole in the brake fluid
reservoir. Bleed the hydraulic brake system as
described in Chapter 10.
Key to Fig 7:8 k Distance of centre rear bracket, for
jacking up the vehicle, from floor level (8.90 inch)
Half-track = 22.264 inch ±.059 inch
FIG 7 : 8 Position of rear suspension f o r rear wheel
toe-in inspection and adjustment ('500 Station Wagon') FIG 7 : 7 Adjusting rear wheel toe-in angle
Key to Fig 7 : 7 Rear wheel plane must be perpendicular to
ground and parallel to car longitudinal centerline with a
tolerance of 0° 10'
To adjust rear wheel geometry, move suitably the swinging arm
outer support. Slight movements are permitted by the play
existing between the support holes A and the mounting screws.
Screws B must be tightened to 28.9 to 36.2 Ibft (4000 to 5000
kg mm). Nuts C must be tightened to 43.4 to 50.6 Ib ft (6000
to 7000 kgmm), after adjustment has been carried out. (These
directions and specifications are also applicable to 500 Station
Wagon).

FIG 7:9 Adjusting rear wheel toe-in on '500 StationWagon'
FIG 7:10 Checking left rear wheel toe-in
84
6 Insert the inner spring between the axle shaft and the
wheel shaft and couple the spline sleeve to the joint
and tighten the screws to a torque wrench setting of
20.3 Ib/ft.
7 Reconnect the parking brake tie rod and adjust the
position of the cable using the two stretchers.
8 Refit the wheels and draw up the mounting screws to
a torque wrench setting of 32.5 to 39.8 Ib/ft. Carefully
lower the vehicle to the floor.
7 :6 Checking and adjusting rear wheel toe-in
This check should be carried out by a Fiat agent as
special setting equipment is necessary. However, details
of this check are given for reference purposes:
To check and adjust the rear wheel geometry proceed
as follows:
1 Place the vehicle on firmly based stands and remove
the front and rear wheels.
2 Install Fiat fixtures A.66062 as shown in FIG 7:12 to
enable correct spring compression and wheel location
in the vertical position.
3 Lift the rear suspensions by compressing the coil
springs and shock absorbers using garage hydraulic
jacks. Screw on the fixture lower shank until the
index registers with the mark 'Nuova 500' stamped on
the bracket. In this position the wheel plane is vertical
and the centre O (see FIG 7 : 6) of wheel shaft results
at 5.00 inch from the buffer stop bracket.
4 Secure Fiat support C.696/3 to the wheel drum and
connect gauge C.696 to the support. Tighten the two
clamping screws as shown in FIG 7:12.
5 Apply at the front of Fiat gauge C.696 bracket
numbered C.696/3 as shown in FIG 7:11.
6 Check that the pin mounted on the front end of the
bracket C.696/3 is in touch with the front suspension
swinging arm pin (see FIG 7:11). If these conditions
are not complied with, proceed with item 7.
Wheel toe-in angle
will vary by 0° 10' under
a movement of some 7/32 inch measured at 72.476 inch
from wheel centre for Model 500D, and at 76.413 inch
from wheel centre for 500 Station Wagon NOTE - - that the toe-in angle
Key to Fig 7 : 9 A Front support B Screw holes for
fixing support to underbody C Swinging arm pin nuts