Chrysler RAM TRUCK 2500 1994 Service Manual page 755

FEELER GAUGE
J 9 2 0 9 - 1 3 6
Fig. 4 Measuring Piston Ring Side Clearance
(d) Pistons with insufficient or excessive side
clearance should be replaced.
(3) Orient the rings:
(a) Arrange top compression ring 90° counter­
clockwise from the oil ring rail gap (Fig. 5).
(b) Arrange second compression ring 90° clock­
wise from the oil ring rail gap (Fig. 5).
OIL RING
S P A C E R G A P
TOP
COMPRESSION
RING GAP
SECOND
COMPRESSION
RING GAP
OIL RING RAIL
GAP (TOP)
OIL RING RAIL
GAP (BOTTOM) J9309-80
Fig. S Proper Ring Installation
CONNECTING ROD BEARINGS
Fit all rods on a bank until completed. DO NOT al­
ternate from one bank to another, because connecting
rods and pistons are not interchangeable from one
bank to another.
The bearing caps are not interchangeable and
should be marked at removal to ensure correct as­
sembly.
Each bearing cap has a small V-groove across the
parting face. When installing the lower bearing shell,
make certain that the V-groove i n the shell is i n line
with the V-groove i n the cap. This provides lubrica­
tion of the cylinder wall i n the opposite bank.
The bearing shells must be installed so that the
tangs are i n the machined grooves i n the rods and
caps.
Limits of taper or out-of-round on any crankshaft
journals should be held to 0.025 mm (0.001 inch).
Bearings are available i n 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. DO NOT use a
new bearing half with an o l d bearing half. DO
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 i n 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. A t 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. Be sure connecting rod, con­
necting rod cap and cylinder bore number are the
same. 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 near the notch of the
No.6 crankshaft counterweight (Fig. 6).
F O R E X A M P L E : R2 stamped on the No.6 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.
When a crankshaft is replaced, all main and con­
necting rod bearings should be replaced with new