Flywheel And Starter Ring Gear; The Oil Pump; Engine Lubrication Diagram; Pump Removal And Reassembly - Fiat 500L Workshop Manual

After the crankshaft has been reground it is important
that all traces of swarf are removed by constant washing
and then drying with a non-fluffy rag.
The clearance between the main bearings and journals
3
must be checked before installing the crankshaft in the
engine. It should also serve as a recheck after the
crankshaft has been reground.
Measure the maximum
diameter and the minimum journal diameter using
accurate measuring equipment. The clearance must not
exceed .0039 inch otherwise the journals must be
reground and undersize bearings fitted.
Undersize bearings with .0394 inch stock on the
internal diameter are also supplied unmounted. They
must be press fitted in the supports, the recommended
interference fit being .00039 to .00197 inch. After
pressing the bearing into the support, a hole is drilled in
the bearing in line with the location dowel hole in the
support. The hole is finished with a suitable expanding
reamer, such as Fiat U.0334, and the dowel pressed in,
noting that the hollow dowel fits in the flywheel end
support.
The next stage is to heat the assembly in an oven or
oil bath for a period of one hour at 150°C (302°F).
When the assembly has cooled to room temperature,
the bearing is reamed in a lathe to match the crankshaft
journal size.
Crankshaft oil seals:
Two inner spring rubber oil seals are located, one in a
special seat in the timing gear cover and the other in the
flywheel end of the crankshaft support and provide oil
tightness. These seals are shown in FIGS 1 :3 and 1 :34.
Whenever the engine is dismantled for overhaul these
seals should be carefully inspected for correct seating and
that the inner seal surface is not worn and that the contact
area is perfect both on the crankshaft and on the fan and
generator drive pulley hub.
Clutch shaft pilot bushing:
A self-lubricating bronze bush is fitted in the end of the
crankshaft as shown in FIG 1 :34 and provides a bearing
for the clutch shaft. Should the bush be worn use Fiat
puller A.40006/1 /2 to remove the worn bush. A new bush
should be fitted using a suitably sized drift.

1:12 Flywheel and starter ring gear

The flywheel should be inspected for wear at the clutch
driven plate contact area. It should be flat and have a
smooth finish.
The ring gear teeth should be cheeked for damage
which if evident, the ring gear must be replaced. To facili-
tate the fitting of a new ring gear on the flywheel, the new
ring gear should be heated in an oil bath to a temperature
of 80°C (176°F). Using a press gently ease the expanded
ring gear over the flywheel and press fully home.

1:13 The oil pump

Sedan :
A helical-spur gear type oil pump is driven by the cam-
shaft through a front dog drive coupling. The gears are
F500
main bearing internal
FIG 1:36

Engine lubrication diagram

Key t o Fig 1 :36
2
Rocker shaft
4
Ducts, cylinder head oil drain
6
Oil pressure relief valve
to centrifugal filter
9
Centrifugal oil fitter
with central oil gallery
12 Sump cooling air conveyor
indicator sending unit
located in a special housing in the timing gear cover and
held in place by a cover plate. The oil pressure relief valve
is mounted on the drive gear shaft guide.
A pump suction scoop fitted with a filter screen is
secured in the crankcase and connects to a duct in the
timing gear case as shown in FIG 1 :36.

Pump removal and reassembly:

To remove the pump from the engine proceed as
follows:
Remove the engine rear central support from the timing
1
gear casing. Remove the filter cover pulley and lift
away the drive belt.
Release the hollow screw attaching the slinger and the
2
mounting flange of the filter on the crankshaft. Also
release the nuts fixing the timing gear cover to the
crankcase.
3 Remove the timing gear cover together with the oil
pump assembly and the pressure relief valve.
4
Lift out the oil pump suction scoop with the filter
screen attached from the sump.
5
Reassembly of the pump to the engine is the reverse
procedure to dismantling.
Oil filler with vent valve
1
3 Line, oil delivery to rocker shaft
5 Level indicator rod
7 Gear pump
8 Oil duct
10 Crankshaft
Oil pump intake screen filter
11
13 Low oil pressure
25