Position the gauge body (2) and dial indicator (1) in
order to measure the piston height above the cylinder
block. Slowly rotate the crankshaft in order to determine
when the piston is at the highest position. Record this
dimension. Compare this dimension with the dimension
that is given in Specifications, "Pistons and Rings".
Inspection Of Connecting Rods
These procedures determine the following characteristics of
the connecting rod:
the length of the connecting rod
the distortion of the connecting rod
the parallel alignment of the bores of the connecting rod
NOTE: If the crankshaft or the cylinder block are
replaced, the piston height for all cylinders must
be measured. The grade of length of the
connecting rods may need to be changed in order
to obtain the correct piston height.
If the grade of length must be changed, one of the following
actions must be taken:
New connecting rod assemblies that are the correct
grade of length must be installed. Refer to "Length Of A
New piston pin bearings must be bored after installation
in the original connecting rods. Refer to "Piston Pin
NOTE: When the piston pin is installed, always install
new retaining rings on each end of the piston pin.
If the piston pin cannot be removed by hand, heat
the piston to a temperature of 45 ° ± 5 ° C
(113 ° ± 9 ° F) in order to aid the removal of the
piston pin. Heating the piston to this temperature
may also aid the installation of the piston pin.
There is a recess on the face of the connecting
rod. The recess is for the piston pin. The recess
must always face the same side as the bore for
the journal bearing.
Length Of A Connecting Rod
CRL is the length of the connecting rod. Refer to Table 22 for
each grade of length of connecting rod.
In order to ensure that the piston height above the cylinder
block is correct, six grades of length of connecting rods are
used. The grade of length is identified by a letter or a color
which is marked on the side of the connecting rod. The
longest grade is marked with the letter "F". The shortest grade
is marked with the letter "L". The difference in length between
each grade of connecting rods is the following value: 0.046 mm
The grade of length of a connecting rod is determined in the
factory by machining an eccentric hole in a semi-finished
piston pin bushing. Therefore, the grade of length is
determined by the position of the center of the hole in the
piston pin bearing. There is a hole that is in the connecting rod
for the piston pin bearing. The grade of length is not
determined by the position of the hole that is in the connecting
rod for the piston pin bearing.
If the connecting rod must be replaced, a new connecting rod
assembly must be purchased and installed. Refer to Table 22
for more information.
A new piston pin bearing is installed in the new connecting rod
at the factory. The bore of the piston pin bearing is reamed to
the correct eccentricity.
Piston Pin Bearings
NOTE: This procedure requires personnel with the
correct training and the use of specialized
equipment for machining.
If the piston pin bearing requires replacement but the original
connecting rod is not replaced, the following procedures must
Determine the grade of length of the connecting rod.
Use one of the following characteristics:
Measuring the length
NOTE: The length of the connecting rod is measured
when the following items are completed: Remove
the bearing for the crankshaft journal. Install the
original piston pin bearing in the connecting rod.
Refer to "Measure The Length Of A Connecting
Ensure that the connecting rod is aligned parallel and
that the connecting rod is not distorted. Refer to
"Distortion Of A Connecting Rod" in this service manual.