Dodge 2001 Ram 1500 Owner's Manual page 1432

BR/BE
PISTON & CONNECTING ROD (Continued)
Fig. 127 Piston Grading Measurement
REMOVAL
(1) Disconnect the battery cables.
(2) Remove the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
(3) Remove the oil pan and suction tube (Refer to 9
- ENGINE/LUBRICATION/OIL PAN - REMOVAL).
(4) Using Miller Tool 7471-B crankshaft barring
tool, rotate the crankshaft so all of the pistons are
below TDC.
(5) Before removing the piston(s) from the bore(s):
(a) Remove any carbon ridge formations or
deposits at the top of the bore with a dull scraper
or soft wire brush.
(b) If cylinder bore wear ridges are found, use a
ridge reamer to cut the ridge from the bore. DO
NOT remove more metal than necessary to remove
the ridge.
NOTE: If cylinders have ridges, the cylinders are
oversize and will more than likely need boring.
(6) Using a hammer and steel stamp, identify the
front of the piston by stamping the cylinder number
in each piston to be removed at the top of the piston
toward the front of the engine. DO NOT stamp in the
outside 5 mm (.197 in.) of the piston diameter.
ENGINE 5.9L DIESEL
(7) Mark the connecting rod and cap with the cor-
responding cylinder numbers.
(8) Remove the connecting rod bolts and rod caps.
Use care so the cylinder bores and connecting rods
are not damaged.
(9) Use a hammer handle or similar object to push
the piston and connecting rod through the cylinder
bore.
(10) Store the piston/rod assemblies in a rack.
(11) If a piston must be replaced, replace with the
same part number (grading) that was removed.
CLEANING
CAUTION: DO NOT use bead blast to clean the pis-
tons. DO NOT clean the pistons and rods in an acid
tank.
Clean the pistons and pins in a suitable solvent,
rinse in hot water and blow dry with compressed air.
Soaking the pistons over night will loosen most of the
carbon build up. De-carbon the ring grooves with a
broken piston ring and again clean the pistons in sol-
vent. Rinse in hot water and blow dry with com-
pressed air.
INSPECTION
Inspect the pistons for damage and excessive wear.
Check top of the piston, ring grooves, skirt and pin
bore. Measure the piston skirt diameter (Fig. 128). If
the piston is out of limits, replace the piston.
The upper groove only needs to be inspected for
damage. Use a new piston ring to measure the clear-
ance in the intermediate ring groove (Fig. 129). If the
clearance of the intermediate ring exceeds 0.095 mm
(0.0038 inch), replace the piston.
Use a new oil ring to measure the clearance in the
oil groove (Fig. 129). If the clearance exceeds 0.085
mm (0.0034 inch), replace the piston.
Measure the pin bore (Fig. 130). The maximum
diameter is 40.012 mm (1.5753 inch). If the bore is
over limits, replace the piston.
Inspect the piston pin for nicks, gouges and exces-
sive wear. Measure the pin diameter (Fig. 131). The
minimum diameter is 39.990 mm (1.5744 inch). If the
diameter is out of limits, replace the pin.
9 - 285