Fiat 55 Automobile User Manual


 
6 Remove the spring seat (photo).
7 Discard the valve stem oil seal and fit a new
one (photo).
8 Remove the remaining valves in a similar
way and keep the components in their
originally fitted sequence.
9 Reassembly is a reversal of removal. Refit
the components to their original positions, but
renew the valve springs if their free length is
less than that of a new spring or if the
springs have been in operation for more than
80 000 km (50 000 miles).
10 The original valve clearance adjusting
shims will no longer provide the correct
clearances if the valves have been ground in
or the seats recut. Only where dismantling of
a valve was carried out to renew a spring is
there any purpose in returning the shims to
their original locations. Try to obtain the loan
of eight thin shims from your dealer and insert
them into the tappets (cam followers) before
assembling the cam followers to the carrier,
where they should be retained with thick
grease (photo).
11 Fit the camshaft carrier, complete with
cam followers and shims to the cylinder head.
12 Adjust the valve clearances as described
in Section 26.
40 Examination and renovation
4
1 The procedures are similar to those
described in Section 18 covering the
following:
Cylinder block and crankcase
Crankshaft and bearings
Pistons and piston rings
Flywheel
2 The following additional items must also be
examined.
Oil pump
3 Carefully, clamp the pump housing in a
vice, shaft downwards.
4 Take off the pump cover, with the suction
pipe. This will release the oil pressure relief
valve inside. Also inside is a filter.
5 Remove the internal cover plate.
6 Take out the driveshaft and the gears.
7 Clean and examine all the parts. Measure
the clearances against the Specifications. The
end clearance is measured by putting a
straight-edge across the cover face.
8 The oil pump should only need
replacements after very long mileage, when
the rest of the engine is showing great signs
of wear.
9 The length of a new gear can be measured
against the old gear to see if a new gear will
restore the end clearance to the Specifica-
tions. Otherwise the housing must be
changed.
10 The driven gear shaft is mounted in the
housing with an interference fit. If there is any
slackness, a new housing (which will come
with shaft fitted) must be used.
11 The oil pump shares its drive with the
distributor.
Camshaft, cam followers and
shims
12 The camshaft journals and cams should
be smooth, without grooves or scores.
13 Wear in the camshaft carrier bearings can
only be rectified by renewal of the carrier.
14 Cam follower wear is usually very small
and when they show slackness in their bores,
it is probably the light alloy of the camshaft
carrier which has worn.
15 Always measure the thickness of the valve
clearance shims using a metric micrometer.
Any grooving or wear marks in the shims
should be rectified by renewal with ones of
similar thickness.
Auxiliary shaft
16 The shaft journals, the fuel pump
eccentric, and the drivegear for the distributor
and oil pump should be smooth and shiny. If
not, the shaft will have to be renewed.
17 The bushes should still be tight in the
cylinder block, their oil holes lined up with
those in the block.
18 Measure the bearing clearance. If
excessive, the bushes will have to be
renewed. They are a press fit, and require
reaming with a special reamer after fitting.
This is a job best done by a Fiat agent with the
special tools.
19 Ensure the new bushes are fitted with the
oil holes lined up.
20 Also check the driven gear and its bush.
21 It is recommended a new oil seal is fitted
in the endplate. Hold the shaft in a vice, and
remove the pulley. Fit the new oil seal in the
endplate, lips inwards.
Timing belt tensioner
22 Check the bearing revolves smoothly and
freely, and has no play. Do not immerse it in
cleaning fluid, as it is partially sealed. Wipe
the outside, and then smear in some new
general purpose grease.
23 The action of the spring will have been felt
when the belt was taken off. It should be
cleaned, and oiled, to prevent seizure through
dirt and rust.
24 Note the circlip on the engine right-hand
mounting bracket. This retains the timing belt
tensioner plunger.
1116 cc and 1301 cc engine 1•29
39.6 Valve spring seat39.5 Removing a valve39.4B Double valve springs
39.10 Cam followers fitted to camshaft
carrier
39.7 Valve stem oil seal
1