Chrysler RAM TRUCK 2500 1994 Service Manual page 724

• ENGINES 9 - 3
provide a satisfactory surface. Using honing oil
C-3501-3880 or a light honing oil available from ma­
jor oil distributors.
CAUTION: DO NOT use engine or t r a n s m i s s i o n oil,
mineral spirits or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a Crosshatch pattern.
The hone marks should INTERSECT at 50° to 60°
for proper seating of rings (Fig. 1).
Fig. 1 Cylinder Bore Crosshatch Pattern
(4) A controlled hone motor speed between 200 and
300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50° to 60°
angle. Faster up and down strokes increase the cross-
hatch angle.
(5) After honing, i t is necessary that the block be
cleaned to remove all traces of abrasive. Use a brush
to wash parts with a solution of hot water and deter­
gent. Dry parts thoroughly. Use a clean, white, lint-
free cloth to check that the bore is clean. Oil the
bores after cleaning to prevent rusting.
MEASURING WITH PLASTIGAGE
CRANKSHAFT MAIN BEARING CLEARANCE
Engine crankshaft bearing clearances can be deter­
mined by use of Plastigage, or equivalent. The follow­
ing is the recommended procedures for the use of
Plastigage:
(1) Remove oil film from surface to be checked.
Plastigage is soluble i n oil.
(2) The total clearance of the main bearings can
only be determined by removing the weight of the
crankshaft. This can be accomplished by either of two
methods:
M E T H O D - 1 (PREFERRED)—Shim the bear­
ings adjacent to the bearing to be checked. This will
remove the clearance between upper bearing shell
and the crankshaft. Place a minimum of 0.254 mm
(0.010 inch) shim between the bearing shell and the
adjacent bearing cap. Tighten the bolts to 18 N-m (13
ft. lbs.) torque.
• CHECK N O . l BEARING? Shim No.2 main bear­
ing.
• CHECK NO.2 B E A R I N G ; Shim N o . l and No.3
main bearing.
• CHECK NO.3 BEARINGs Shim No.2 and No.4
main bearing.
• CHECK NO.4 BEARINGs Shim No.3 main bear­
ing (3.9L). Shim No.3 and No.5 main bearing (5.2L,
5.9L, 8.0L and 5.9L-Diesel).
• CHECK NO.5 BEARINGs Shim No.4 main bear­
ing (5.2L and 5.9L). Shim No.4 and No.6 main bear­
ing (8.0L and 5.9L-Diesel).
• CHECK NO.6 B E A R I N G : Shim No.5 main bear­
ing (8.0L). Shim No.5 and No.7 main bearing (5.9L-
Diesel).
• C H E C K NO.7 B E A R I N G : Shim No.6 main bear­
ing (5.9L-Diesel).
R e m o v e a l l s h i m s before a s s e m b l i n g e n g i n e .
M E T H O D - 2 (ALTERNATIVE)—The weight of
the crankshaft is supported by a jack under the coun­
terweight adjacent to the bearing being checked.
(3) Place a piece of Plastigage across the entire
width of the bearing cap shell (Fig. 2). Position the
Plastigage approximately 6.35 mm (1/4 inch) off cen­
ter and away from the oil holes. I n addition, suspect
areas can be checked by placing the Plastigage i n
that area. Tighten the bearing cap bolts of the bear­
ing being checked to 115 N-m (85 ft. lbs.) torque. D O
N O T rotate t h e c r a n k s h a f t o r t h e P l a s t i g a g e
m a y b e s m e a r e d , g i v i n g i n a c c u r a t e r e s u l t s .
L90
Fig. 2 Placement of Plastigage in Bearing Shell
(4) Remove the bearing cap and compare the width
of the flattened Plastigage with the scale provided on
the package (Fig. 3). Plastigage generally comes i n 2
scales (one scale is i n inches and the other is a met­
ric scale). Locate the band closest to the same width.
This band shows the amount of clearance. Differ­
ences i n readings between the ends indicate the
amount of taper present. Record all readings taken
(refer to Engine Specifications).