Checking The Piston Pin

CONNECTING RODS AND PISTONS

2. Install:                                             2. Measure:
 • Piston ring                                           • Piston pin outside diameter “a”
   (into the cylinder)                                     Out of specification → Replace the piston pin.
NOTE:
                                                                   Piston pin outside diameter
Level the piston ring into the cylinder with the                    18.991–19.000 mm (0.7477–
piston crown.                                                       0.7480 in)
                                                                   Limit
                                                                    18.971 mm (0.7469 in)

  a. 5 mm (0.20 in)
3. Measure:
 • Piston ring end gap                                  3. Measure:
   Out of specification → Replace the piston             • Piston pin bore diameter “b”
   ring.                                                   Out of specification → Replace the piston.
NOTE:
                                                                   Piston pin bore inside diameter
The oil ring expander spacer’s end gap cannot                       19.004–19.015 mm (0.7482–
be measured. If the oil ring rail’s gap is exces-                   0.7486 in)
sive, replace all three piston rings.                              Limit
                                                                    19.045 mm (0.7498 in)
           Piston ring
            Top ring
              End gap (installed)
               0.35–0.45 mm (0.0138–0.0177
               in)
              Limit
               0.70 mm (0.0276 in)
            2nd ring
              End gap (installed)
               0.75–0.85 mm (0.0295–0.0335
               in)
              Limit                                     4. Calculate:
               1.20 mm (0.0472 in)                        • Piston-pin-to-piston-pin-bore clearance
            Oil ring                                        Out of specification → Replace the piston pin
              End gap (installed)                           and piston as a set.
               0.20–0.60 mm (0.0079–0.0236
               in)                                       • Piston-pin-to-piston-pin-bore clearance =
                                                           Piston pin bore diameter “b” -
                                                           Piston pin outside diameter “a”
EAS24440

CHECKING THE PISTON PIN
The following procedure applies to all of the pis-                 Piston-pin-to-piston-pin-bore
ton pins.                                                          clearance
1. Check:                                                           0.004–0.024 mm (0.00016–
  • Piston pin                                                      0.00094 in)
    Blue discoloration/grooves → Replace the
    piston pin and then check the lubrication sys-
    tem.

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