Case 445/M2 - Piston Pins; Conditions for Proper Pin−Piston Coupling; Split Rings

32620
16552
32619
18857
41104
Figure 45
Figure 46
Figure 47
Figure 48
Figure 49
To measure the piston pin (1) diameter use the micrometer
(2).
Conditions for proper pin−piston coupling
Lubricate the pin (1) and its seat on piston hubs with engine
oil; the pin shall be fitted into the piston with a slight finger
pressure and shall not be withdrawn by gravity.
Use a micrometer (1) to check split ring (2) thickness.
Check the clearance between the sealing rings (3) of the 2
nd
and 3
rd
slot and the relevant housings on the piston (2), using
a feeler gauge (1).
DIAGRAM FOR MEASURING THE CLEARANCE X
BETWEEN THE FIRST PISTON SLOT AND THE
TRAPEZOIDAL RING
Since the fir st sealing ring section is trapezoidal, the clearance
between the slot and th e r in g shall be measured as follows:
make the piston (1) protrude from the engine block so that
the ring (2) protrudes half−way from the c ylinder barrel (3).
In this position, use a feeler gauge to check the clearance (X)
between ring and slot: found value shall be the specified one .
Piston pins
Split rings
SECTION 4 − OVERHAUL AND TECHNICAL SPECIFICATIONS
24
E NG I NE S
ED. FEBUARY 2003