Inspection—Measuring Timing Chain Stretch; Measuring Timing Chain Wear And Stretch - Dodge 2001 Ram 1500 Owner's Manual

9 - 58 ENGINE 3.9L
TIMING BELT/CHAIN AND SPROCKETS (Continued)
INSPECTION—MEASURING TIMING CHAIN
STRETCH
NOTE: Timing chain tensioner must be removed for
this operation.
(1) Place a scale next to the timing chain so that
any movement of the chain can be measured.
(2) Place a torque wrench and socket over cam-
shaft sprocket attaching bolt. Apply torque in the
direction of crankshaft rotation to take up slack; 41
N·m (30 ft. lbs.) torque with cylinder head installed
or 20 N·m (15 ft. lbs.) torque with cylinder head
removed. With torque applied to the camshaft
sprocket bolt, crankshaft should not be permitted to
move. It may be necessary to block the crankshaft to
prevent rotation.
(3) Hold a scale with dimensional reading even
with the edge of a chain link. With cylinder heads
installed, apply 14 N·m (30 ft. lbs.) torque in the
reverse direction. With the cylinder heads removed,
apply 20 N·m (15 ft. lbs.) torque in the reverse direc-
tion. Note the amount of chain movement (Fig. 76).
Fig. 76 Measuring Timing Chain Wear and Stretch
1 - TORQUE WRENCH
2 - 3.175 MM
(0.125 IN.)
(4) Install a new timing chain, if its movement
exceeds 3.175 mm (1/8 inch).
INSTALLATION
(1) If tensioner assembly is being replaced, install
tensioner and mounting bolts. Torque bolts to 24 N·m
(210 in. lbs.).
(2) Place both camshaft sprocket and crankshaft
sprocket on the bench with timing marks on an exact
imaginary center line through both camshaft and
crankshaft bores.
(3) Place timing chain around both sprockets.
(4) Lift sprockets and chain (keep sprockets tight
against the chain in position as described).
(5) Slide both sprockets evenly over their respec-
tive shafts and verify alignment of timing marks
(Fig. 77) with a straight-edge if necessary.
Fig. 77 Alignment of Timing Marks
1 - TIMING MARKS
(6) Install the camshaft bolt. Tighten the bolt to 68
N·m (50 ft. lbs.) torque.
(7) Remove tensioner pin. Again, verify align-
ment of timing marks.
(8) Install timing cover (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- INSTALLATION).
(9) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(10) Connect battery negative cable.
(11) Start engine and check for oil and coolant
leaks.
BR/BE