Dodge RAM 1500 1998 Owner's Manual page 1273

9 - 50 ENGINE - 3.7L
PISTON & CONNECTING ROD (Continued)
(3) Use piston ring compressor and Guide Pins
Special Tool 8507 (Fig. 48) to install the rod and pis-
ton assemblies. The oil slinger slots in the rods must
face front of the engine. The "F"'s near the piston
wrist pin bore should point to the front of the engine.
Fig. 48 Piston and Connecting Rod -Installation -
1 - "F" TOWARD FRONT OF ENGINE
2 - OIL SLINGER SLOT
3 - RING COMPRESSOR
4 - SPECIAL TOOL 8507
(4) Install the lower bearing insert in the bearing
cap. Center bearing insert in connecting rod (Fig. 47).
The lower insert must be dry. Place strip of Plasti-
gage across full width of the lower insert at the cen-
ter of bearing cap. Plastigage must not crumble in
use. If brittle, obtain fresh stock.
(5) Install bearing cap and connecting rod on the
journal and tighten bolts to 27 N·m (20 ft. lbs.) plus a
90° turn. DO NOT rotate crankshaft. Plastigage will
smear, resulting in inaccurate indication.
(6) Remove the bearing cap and determine amount
of bearing-to-journal clearance by measuring the
width of compressed Plastigage (Fig. 49). Refer to
Engine Specifications for the proper clearance. Plas-
tigage should indicate the same clearance
across the entire width of the insert. If the
clearance varies, it may be caused by either a
Typical
tapered journal, bent connecting rod or foreign
material trapped between the insert and cap or
rod.
Fig. 49 Measuring Bearing Clearance with
Plastigage
1 - PLASTIGAGE SCALE
2 - COMPRESSED PLASTIGAGE
(7) If the correct clearance is indicated, replace-
ment of the bearing inserts is not necessary. Remove
the Plastigage from crankshaft journal and bearing
insert. Proceed with installation.
(8) If bearing-to-journal clearance exceeds the
specification, determin which services bearing set to
use the bearing sizes are as follows:
Bearing SIZE
Mark
.025 US .025 mm
(.001 in.)
Std. STANDARD
.250 US .250 mm
(.010 in.)
CAUTION: Connecting Rod Bolts are Torque to
Yield Bolts and Must Not Be Reused. Always
replace the Rod Bolts whenever they are loosened
or removed.
(9) Repeat the Plastigage measurement to verify
your bearing selection prior to final assembly.
DR
USED WITH
JOURNAL SIZE
57.883-57.867 mm
(2.2788-2.2783 in.)
57.908-57.892 mm
(2.2798-2.2792 in.)
57.658-57.646 mm
(2.2700-2.2695 in.)