Chrysler RAM TRUCK 2500 1994 Service Manual page 809

OIL RING
SPACER GAP
TOP
COMPRESSION
RING GAP
SECOND
COMPRESSION
RING GAP
OIL RING RAIL
GAP (TOP)
OIL RING RAIL
GAP (BOTTOM)
J9309-80
Fig. 5 Proper Ring Installation
Limits of taper or out-of-round on any crankshaft
journals should be held to 0.025 mm (0.001 inch).
Bearings are available in 0.025 mm (0.001 inch),
0.051 mm (0.002 inch), 0.076 mm (0.003 inch), 0.254
mm (0.010 inch) and 0.305 mm (0.012 inch) under­
size. Install the bearings in pairs. D O N O T use a
new bearing half with an old bearing half. D O
NOT file the rods or bearing caps.
INSTALLATION
(1) Be sure that compression ring gaps are stag­
gered so that neither is in line with oil ring rail gap.
(2) Before installing the ring compressor, make
sure the oil ring expander ends are butted and the
rail gaps located properly (Fig. 5).
(3) Immerse the piston head and rings in clean en­
gine oil. Slide Piston Ring Compressor Tool C-385
over the piston and tighten with the special wrench
(part of Tool C-385). Be sure position of rings
does not change during this operation.
(4) Install connecting rod bolt protectors on rod
bolts, the long protector should be installed on the
numbered side of the connecting rod.
(5) Rotate crankshaft so that the connecting rod
journal is on the center of the cylinder bore. Be sure
connecting rod and cylinder bore number are the
same. Insert rod and piston into cylinder bore and
guide rod over the crankshaft journal.
(6) Tap the piston down in cylinder bore, using a
hammer handle. At the same time, guide connecting
rod into position on crankshaft journal.
(7) The notch or groove on top of piston must be
pointing toward front of engine. The larger chamfer
of the connecting rod bore must be installed toward
crankshaft journal fillet.
(8) Install rod caps. Install nuts on cleaned and
oiled rod bolts and tighten nuts to 61 N-m (45 ft. lbs.)
torque.
(9) Install the oil pan.
(10) Install the cylinder head.
(11) Install the engine into the vehicle.
CRANKSHAFT
A crankshaft which has undersize journals will be
stamped with 1/4 inch letters on the milled flat on
the No.3 crankshaft counterweight (Fig. 6).
F O R EXAMPLE? R2 stamped on the No.3 crank­
shaft counterweight indicates that the No.2 rod jour­
nal is 0.025 mm (0.001 in) undersize. M4 indicates
that the No.4 main journal is 0.025 mm (0.001 in)
undersize. R3 M2 indicates that the No.3 rod journal
and the No.2 main journal are 0.025 mm (0.001 in)
undersize.
Undersize Journal
Identification Stamp
0.025 mm (0.001 inch) (Rod)
0.025 mm (0.001 inch) (Main)
R1-R2-R3 or R4
M1-M2-M3-M4 or M5
Z * -
(ROD)
4-(MAIN)
U L J J9309-52
Fig. 6 Location of Crankshaft Identification
When a crankshaft is replaced, all main and con­
necting rod bearings should be replaced with new
bearings. Therefore, selective fitting of the bearings
is not required when a crankshaft and bearings are
replaced.
REMOVAL
(1) Remove
(2) Remove
ing cap.
(3) Remove
(4) Remove
(5) Identify
bearing caps
(6) Lift the
(7) Remove
seals.
(8) Remove
seal.
the oil pan.
the oil pump from the rear main bear-
the vibration damper,
the timing chain cover,
bearing caps before removal. Remove
and bearings one at a time,
crankshaft out of the block,
and discard the crankshaft rear oil
and discard the front crankshaft oil
INSPECTION OF JOURNALS
The crankshaft connecting rod and main journals
should be checked for excessive wear, taper and scor­
ing. The maximum taper or out-of-round on any
crankshaft journal is 0.025 mm (0.001 inch).
Journal grinding should not exceed 0.305 mm
(0.012 inch) under the standard journal diameter. DO