Crankshaft Cleaning And Inspection; Flywheel Inspection; Connecting Rods Cleaning And Inspection; Pistons, Pins And Rings Cleaning And Inspection - Ford VSG-411 Service Manual

Basic Engine
l-12
NO PITTING
t J
ALLOWED IN
THIS AREA
l/4" l/4"
DIMENSION A MINUS
DIMENSIO N B EQUALS
LOBE LIFT
A A64898
FIG.
20
Camshaft Lobe Lift Measurement -
Camshaft Removed
2. If the readings do not meet specification, replace the
camshaft.
CAMSHAFT BORES
Inspection
Check camshaft bores for size, taper, roundness, runout, and
finish. If any of these dimensions exceeds the limits given in
Specifications, install new camshaft bearings.
CRANKSHAFT
Cleaning
Handle the crankshaft with care to avoid possible fractures or
damage to the finished surfaces. Clean the crankshaft with sol-
vent, then blow out all oil passages with compressed air.
Inspection
Inspect the main and connecting rod journals for cracks,
scratches, grooves or scores. Inspect the crankshaft oil seal surface
for nicks, sharp edges or burrs that might damage the oil seal
during installation or cause premature seal wear.
Measure the diameter of each journal in at least four places to
determine an out-of-round, taper or undersize condition (Figure
21).
AVSB=
VERTICAL TAPER
CVSD= HORIZONTAL TAPER
A VS C AND B VS D = OUT OF ROUND
CHECK FOR OUT-OF-ROUND AT EACH END OF JOURNAL
A2901-1B
FIG. 21 Crankshaft Journal Measurement
FLYWHEEL
Inspection
Inspect the flywheel for cracks, heat check, or other damage
that would make it unfit for further service. Machine the friction
surface of the flywheel if it is scored or worn. If it is necessary to
remove more than 0.045 inch of stock from the original thickness,
replace the flywheel.
Inspect the ring gear for worn, chipped, or cracked teeth. If the
teeth are damaged, replace the ring gear.
With the flywheel installed on the crankshaft, check the
flywheel face runout, following the procedure under Diagnosis
and Testing.
CONNECTING RODS
Cleaning
Removing the bearings from the rod and cap. Identify the
bearings if they are to be used again. Clean the connecting rod in
solvent, including the rod bore and the back of the inserts. Do not
use a caustic cleaning solution. Blow out all passages with
compressed air.
Inspection
The connecting rods and related parts should be carefully in-
spected and checked for conformance to specifications. Various
forms of engine wear caused by these parts can be readily
identified.
A shiny surface on either pin boss side of the piston usually
indicates that a connecting rod is bent.
Abnormal connecting rod bearing wear can be caused by either
a bent connecting rod, worn or damaged crankpin, or a tapered
connecting rod bore.
Twisted connecting rods will not create an identifiable wear
pattern, but badly twisted rods will disturb the action of the entire
piston, rings and connecting rod assembly and may be the cause of
excessive oil consumption.
Inspect the connecting rods for signs of fractures and the bearing
bores for out-of-round and taper. If the bore exceeds the recom-
mended limits and/or if the connecting rod is fractured, it should
be replaced. Check the ID of the connecting rod piston pin bore. If
the pin bore in the connecting rod is larger than specifications,
install a 0.002 inch oversize piston pin. First, prefit the oversize
piston pin to the piston pin bore by reaming or honing the piston.
Then, assemble the piston, piston pin and connecting rod follow-
ing the procedures for assembly. It is not necessary to ream or
hone the pin bore in the connecting rod. Replace damaged
connecting rod nuts and bolts. Check the connecting rods for
bend or twist on a suitable alignment fixture. Follow the
instructions of the fixture manufacturer. If the bend and/or
twist exceeds specifications, the connecting rod must be
straightened or replaced.
PISTONS, PINS AND RINGS
Cleaning
Remove deposits from the piston surfaces. Clean gum or var-
nish from the piston skirt, piston pins and rings with solvent. Do
not use a caustic cleaning solution or a wire brush to clean
pistons.
Clean the ring grooves with a ring groove cleaner (Figure 22).
Make sure the oil ring slots (or holes) are clean.
Inspection
Carefully inspect the pistons for fractures at the ring lands,
skirts and pin bosses, and for scuffed, rough or scored skirts. If the
lower inner portion of the ring grooves has a high step, replacethe
piston. The step will interfere with ring operation and cause
excessive ring side clearance.
Spongy, eroded areas near the edge of the top of the piston are
usually caused by detonation or pre-ignition. A shiny surface on