2006 DODGE RAM SRT-10 service

Crankshaft Marking JOURNAL SIZE
SIZE mm (in.)
RSize 63.488 - 63.496 mm
(2.4995 - 2.4998 in.)
SSize 63.496 - 63.500 mm (2.4998 - 2.4999 in.)
TSize 63.500 - 63.504 mm (2.4999 - 2.501 in.)
USize 63.504 - 63.512 mm (2.5001 - 2.5004 in.)
Bearing size
Bearing Code Size Application
Upper Bearing
A.2.443 - 2.447 mm Use with crankshaft size
R
(.0961 - .0963 in.)
B2.439 - 2.443 mm Use with crankshaft
S, T
(0.960 - .0961 in.)
C2.435 - 2.439 mm Use with crankshaft
U
(.0958 - .0960 in.)
Lower Bearing Main
1and4
12.441 - 2.447 mm Use with crankshaftR, S
(.0961 -.0963 in.)
22.435 - 2.441 mm Use with crankshaftT, U
(.0958 - .0962 in.)
Lower Main Bearing
2and3
32.429 - 2.435 mm Use with crankshaftR, S
(.0956 - .0958 in.)
42.423 - 2.429 mm Use with crankshaftT, U
(.0953 - .0956 in.)
Bearing Clearances
Main
1, 4
CrankshaftR.004 - .034 mm ( .00015 - .0013 in.)
Crankshaft
S.004 - .030 mm ( .00015 - .0011 in.)
Crankshaft
T.006 - .032 mm (.0002 - .0012 in.)
Crankshaft
U.002 - .032 mm (.00007 -. 0012 in.)
Main
2, 3
CrankshaftR.016 - .046 mm (.0006 - .0018 in.)
Crankshaft
S.016 - .042 mm (.00062 - .016 in.)
Crankshaft
T.018 - .044 mm (.0007 - .0017 in.)
Crankshaft
U.014 - .044 mm (.0005 - .0017 in.)
1. Service main bearings are available in four grades. The chart identifies the four service grades available.

4. Install the lower bearing insert in the bearing cap.
Center bearing insert in connecting rod..The
lower insert must be dry. Place strip of Plastigage
across full width of the lower insert at the center of
bearing cap. Plastigage must not crumble in use. If
brittle, obtain fresh stock.
5. Install bearing cap and connecting rod on the jour-
nal and tighten bolts to 27 Nꞏm (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 (2). Refer to
Engine Specifications for the proper clearance.
Plastigage should indicate the same clearance
across the entire width of the insert. If the
clearancevaries,itmaybecausedbyeithera
tapered journal, bent connecting rod or foreign
material trapped between the insert and cap or
rod.
7. If the correct clearance is indicated, replacement of
the bearing inserts is not necessary. Remove the Plastigage from crankshaft journal and bearing insert. Proceed
with installation.
Bearing Mark SIZE USED WITH JOURNAL SIZE
.025 US.025 mm 57.883-57.867 mm
(.001 in.) (2.2788-2.2783 in.)
Std.STANDARD 57.908-57.892 mm
(2.2798-2.2792 in.)
.250 US.250 mm 57.658-57.646 mm
(.010 in.) (2.2700-2.2695 in.)
8. If bearing-to-journal clearance exceeds the specification, determinwhich services bearing set to use the bearing
sizes are as follows:
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.
10. Once you have selected the proper insert, install the insert and cap. Tighten the connecting rod bolts to 27 Nꞏm
(20 ft. lbs.) plus a 90° turn.

Slide snug-fitting feeler gauge between the connecting
rod and crankshaft journal flange. Refer to Engine
Specifications for the proper clearance. Replace the
connecting rod if the side clearance is not within
specification.
STANDARD PROCEDURE - PISTON FITTING
1. To correctly select the proper size piston, a cylinder
bore gauge (2), capable of reading in 0.003 mm (
.0001 in.) INCREMENTS is required. If a bore
gauge is not available, do not use an inside
micrometer.
2. Measure the inside diameter of the cylinder bore
(3) at a point 38.0 mm (1.5 inches) below top of
bore. Start perpendicular (across or at 90 degrees)
to the axis of the crankshaft at point A and then
take an additional bore reading 90 degrees to that
at point B.
3. The coated pistons (1,2) will be serviced with the
piston pin and connecting rod pre-assembled.
4. The coating material is applied to the piston after
the final piston machining process. Measuring the
outside diameter of a coated piston (1,2) will not
provide accurate results. Therefore measuring the
inside diameter of the cylinder bore with a dial Bore
Gauge isMANDATORY. To correctly select the
proper size piston, a cylinder bore gauge capable
of reading in 0.003 mm (.0001 in.) increments is
required.
5. Piston installation intothe cylinder bore requires
slightly more pressure than that required for non-
coated pistons. The bonded coating on the piston
will give the appearance of a line-to-line fit with the
cylinder bore.

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the engine, particularly at thearea of the suspected leak. If an oil leak
source is not readily identifiable, thefollowingstepsshouldbefollowed:
1. Do not clean or degrease the engine at this time because some solvents maycause rubber to swell, temporarily
stopping the leak.
2. Add an oil soluble dye (use as recommended by manufacturer). Start the engine and let idle for approximately 15
minutes. Check the oil dipstick to make sure the dye is thoroughly mixed as indicated with a bright yellow color
under a black light.
3. Using a black light, inspect the entire engine for fluorescent dye, particularly at the suspected area of oil leak. If
the oil leak is found and identified, repair per service manual instructions.
4. If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspec-
tion.If the oil leak source is not positively identified at this time, proceed with the air leak detection test method.
Air Leak Detection Test Method
1. Disconnect the breather cap to air cleaner hose at the breather cap end. Cap or plug breather cap nipple.
2. Remove the PCV valve from the cylinder head cover. Cap or plug the PCV valvegrommet.
3. Attach an air hose with pressure gauge and regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to more than 20.6 kPa (3 PSI) of test pressure.
4. Gradually apply air pressure from 1 psi to 2.5 psi maximum while applyingsoapy water at the suspected source.
Adjust the regulator to the suitable test pressure that provide the best bubbles which will pinpoint the leak
source. If the oil leak is detected and identified, repair per service manual procedures.
5. If the leakage occurs at the rear oil seal area, refer to the section, Inspection for Rear Seal Area Leak.
6. If no leaks are detected, turn off the air supply and remove the air hose and all plugs and caps. Install the PCV
valve and breather cap hose.
7. Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various speeds approx-
imately 24 km (15 miles). Inspect the engine for signs of an oil leak by usinga black light.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in therear seal area of the engine, a more
involved inspection is necessary. The following steps should be followedto help pinpoint the source of the leak.
If the leakage occurs at the crankshaft rear oil seal area:
1. Disconnect the battery.
2. Raise the vehicle.
3. Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light
to check for the oil leak:
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
b. Where leakage tends to run straight down, possible causes are a porous block, oil galley pipe plugs, oil filter
runoff, and main bearing cap to cylinder block mating surfaces.
4. If no leaks are detected, pressurize the crankcase as outlined in the, Inspection (Engine oil Leaks in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
5. If the leak is not detected, very slowly turn the crankshaft and watch forleakage. If a leak is detected between
the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged.
The seal area on the crankshaft could have minor nicks or scratches that canbe polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially machined to complement the function of the rear oil seal.
6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled.

OIL
STANDARD PROCEDURE - ENGINE OIL SERVICE
The engine oil level indicator (1) is located at the right
rear of the engine on the 3.7L/4.7L engines.
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil, pressure loss or oil foaming can result.
Inspect engine oil level approximately every 800 kilometers (500 miles).Unless the engine has exhibited loss of oil
pressure, run the engine for about five minutes before checking oil level.Checking engine oil level on a cold engine
is not accurate.
To ensure proper lubrication of an engine, the engine oil must be maintained at an acceptable level. The acceptable
levels are indicated between the ADD and SAFE marks on the engine oil dipstick.
1. Position vehicle on level surface.
2. With engine OFF, allow approximately ten minutes for oil to settle to bottom of crankcase, remove engine oil
dipstick.
3. Wipe dipstick clean.
4. Install dipstick and verify it is seated in the tube.
5. Remove dipstick, with handle held above the tip, take oil level reading.
6. Add oil only if level is below the ADD mark on dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals described in Maintenance Schedules.
Run engine until achieving normal operating temperature.
1. Position the vehicle on a level surface and turn engine off.
2. Hoist and support vehicle on safety stands.
3. Remove oil fill cap.
4. Place a suitable drain pan under crankcase drain.
5. Remove drain plug from crankcase and allow oil to drain into pan. Inspectdrain plug threads for stretching or
other damage. Replace drain plug if damaged.
6. Install drain plug in crankcase.
7. Lower vehicle and fill crankcase with specified type and amount of engine oil described in this section.
8. Install oil fill cap.
9. Start engine and inspect for leaks.

VALVE TIMING
DESCRIPTION
The timing drive system has been designed to provide quiet performance andreliability to support anon-free
wheelingengine. Specifically the intake valves are non-free wheeling and can be easily damaged with forceful
engine rotation if camshaft-to-crankshaft timing is incorrect. The timing drive system consists of a primary chain (6),
two secondary timing chain drives (1,4) and a counterbalance shaft drive.
OPERATION
The primary timing chain is a single inverted tooth chain type. The primarychaindrivesthelarge50toothidler
sprocket directly from a 25 tooth crankshaft sprocket. Primary chain motion is controlled by a pivoting leaf spring
tensioner arm and a fixed guide. The arm and the guide both use nylon plasticwear faces for low friction and long
wear. The primary chain receives oil splash lubrication from the secondary chain drive and designed oil pump leak-
age. The idler sprocket assembly connects the primary chain drive, secondary chain drives, and the counterbalance
shaft. The idler sprocket assembly consists of two integral 26 tooth sprockets a 50 tooth sprocket and a helical gear
that is press-fit to the assembly. Thespline joint for the 50 tooth sprocket is a non serviceable press fit anti rattle
type. A spiral ring is installed on the outboard side of the 50 tooth sprocket to prevent spline disengagement. The
idler sprocket assembly spins on a stationary idler shaft. The idler shaftis a light press-fit into the cylinder block. A
large washer on the idler shaft bolt and the rear flange of the idler shaft are used to control sprocket thrust move-
ment. Pressurized oil is routed through the center of the idler shaft to provide lubrication for the two bushings used
in the idler sprocket assembly.
There are two secondary drive chains, both are roller type, one to drive thecamshaft in each SOHC cylinder head.
There are no shaft speed changes in the secondary chain drive system. Each secondary chain drives a 26 tooth
cam sprocket directly from the 26 tooth sprocket on the idler sprocket assembly. A fixed chain guide and a hydraulic
oil damped tensioner are used to maintain tension in each secondary chain system. The hydraulic tensioners for the
secondary chain systems are fed pressurized oil from oil reservoir pockets in the block. Each tensioner incorporates
a controlled leak path through a device known as a vent disc located in the nose of the piston to manage chain

loads. Each tensioner also has a mechanical ratchet system that limits chain slack if the tensioner piston bleeds
down after engine shut down. The tensioner arms and guides also utilize nylon wear faces for low friction and long
wear. The secondary timing chains receive lubrication from a small orifice in the tensioners. This orifice is protected
from clogging by a fine mesh screen which is located on the back of the hydraulic tensioners.
STANDARD PROCEDURE
MEASURING TIMING CHAIN WEAR
NOTE: This procedure must be performed with the
timing chain cover removed.
1. Remove the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT/CHAIN
AND SPROCKETS - REMOVAL).
2. To determine if the secondary timing chains are
worn, rotate the engine clockwise until maximum
tensioner piston (2) extension is obtained. Measure
the distance between the secondary timing chain
tensioner housing and the step ledge on the piston.
The measurement at point (A) must be less than
15mm (.5906 inches).
3. If the measurement exceeds the specification the
secondary timing chains are worn and require
replacement (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT/CHAIN AND SPROCKETS -
REMOVAL).
SERVICE PROCEDURE - TIMING VERIFICATION
CAUTION: The 3.7L is a non free-wheeling design
engine. Therefore, correct engine timing is critical.
NOTE:Componentsreferredtoaslefthandor
right hand are as viewed from the drivers position
inside the vehicle.
NOTE: The blue link plates on the chains and the
dots on the camshaft drive sprockets may not line
up during the timing verification procedure. The
blue link plates are lined up with the sprocket dots
only when re-timing the complete timing drive.
Once the timing drive is rotated blue link-to-dot
alignment is no longer valid.
Engine base timing can be verified by the following
procedure:
1. Remove the cylinder head covers. Refer to the pro-
cedure in this section.

SHAFT-BALANCE
REMOVAL
1. Remove the primary and secondary timing chains.
Refer to TIMING CHAIN and SPROCKET.
NOTE: The balance shaft and gear are serviced as
an assembly. Do not attempt to remove the gear
from the balance shaft.Remove the retaining bolt
(4) from the counterbalance shaft thrust plate (2).
2. Using Special Tool 8641 Counterbalance shaft
remover/installer tool (1), remove the counterbal-
ance shaft from the engine .