Dodge Ram Truck 1500-2500-3500. Manual — part 1293

REMOVAL

NOTE: Disconnect the battery negative cable to
prevent accidental starter engagement.

1. Remove the cylinder head cover (Refer to 9 -

ENGINE/CYLINDER

HEAD/CYLINDER

HEAD

COVER(S) - REMOVAL).

2. For rocker arm removal on cylinder No. 4, Rotate

the crankshaft until cylinder No. 1 is at BDC intake
stroke.

3. For rocker arm removal on cylinder No. 1, Rotate

the crankshaft until cylinder No. 1 is at BDC com-
bustion stroke.

4. For rocker arm removal on cylinders No. 3 and No.

5, Rotate the crankshaft until cylinder No. 1 is at
TDC exhaust stroke.

5. For rocker arm removal on cylinders No. 2 and No.

6, Rotate the crankshaft until cylinder No. 1 is at
TDC ignition stroke.

6. Using special tool 8516 Rocker Arm Remover (2) ,

press downward on the valve spring, remove
rocker arm.

SEALS - VALVE GUIDE

DESCRIPTION

The valve guide seals are made of rubber and incorporate an integral steel valve spring seat. The integral garter
spring maintains consistent lubrication control to the valve stems.

SPRINGS - VALVE

DESCRIPTION

The valve springs are made from high strength chrome silicon steel. There are different springs for intake and
exhaust applications. The exhaust spring has an external damper. The valve spring seat is integral with the valve
stem seal, which is a positive type seal to control lubrication.

REMOVAL

1. Remove the cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) -

REMOVAL).

2. Using Special Tool 8516 Valve Spring Compressor, remove the rocker arms and the hydraulic lash adjusters.

3. Remove the spark plug for the cylinder the valve spring and seal are to be removed from.

4. Apply shop air to the cylinder to hold the valves in place when the spring is removed.

NOTE: All six valve springs and seals are removed in the same manner; this procedure only covers one
valve seal and valve spring.

5. Using Special Tool 8387 Valve Spring Compressor, compress the valve spring.

NOTE: It may be necessary to tap the top of the valve spring to loosen the spring retainers locks enough to
be removed.

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ENGINE - 3.7L - SERVICE INFORMATION

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6. Remove the two spring retainer lock halves.

NOTE: the valve spring is under tension use care when releasing the valve spring compressor.

7. Remove the valve spring compressor.

NOTE: The valve springs are NOT common between intake and exhaust.

8. Remove the spring retainer, and the spring.

9. Remove the valve stem seal.

NOTE: The valve stem seals are common between intake and exhaust.

INSTALLATION

NOTE: All six valve springs and seals are removed in the same manner; this procedure only covers one
valve seal and valve spring.

1. Apply shop air to the cylinder to hold the valves in place while the spring is installed.

NOTE: The valve stem seals are common between intake and exhaust.

2. Install the valve stem seal.

NOTE: The valve springs are NOT common between intake and exhaust.

3. Install the spring retainer, and the spring.

4. Using Special Tool 8387 Valve Spring Compressor, compress the valve spring.

5. Install the two spring retainer lock halves.

NOTE: the valve spring is under tension use care when releasing the valve spring compressor.

6. Remove the valve spring compressor.

7. Disconnect the shop air to the cylinder.

8. Install the spark plug for the cylinder the valve spring and seal was installed on.

9. Using Special Tool 8516 Valve Spring Compressor, install the rocker arms and the hydraulic lash adjusters.

10. Install the cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) -

INSTALLATION).

ENGINE BLOCK

DESCRIPTION

The cylinder block is made of cast iron. The block is a closed deck design with the left bank forward. To provide
high rigidity and improved NVH an enhanced compacted graphite bedplate is bolted to the block. The block design
allows coolant flow between the cylinders bores, and an internal coolant bypass to a single poppet inlet thermostat
is included in the cast aluminum front cover.

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ENGINE - 3.7L - SERVICE INFORMATION

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STANDARD PROCEDURE - CYLINDER BORE HONING

Before honing, stuff plenty of clean shop towels under
the bores and over the crankshaft to keep abrasive
materials from entering the crankshaft area.

1. Used carefully, the Cylinder Bore Sizing Hone

C-823, equipped with 220 grit stones, is the best
tool for this job. In addition to deglazing, it will
reduce taper and out-of-round, as well as removing
light scuffing, scoring and scratches. Usually, a few
strokes will clean up a bore and maintain the
required limits.

CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.

2. Deglazing of the cylinder walls may be done if the

cylinder bore is straight and round. Use a cylinder
surfacing hone, Honing Tool C-3501, equipped with
280

grit

stones

(C-3501-3810).

about

20-60

strokes, depending on the bore condition, will be
sufficient to provide a satisfactory surface. Using
honing oil C-3501-3880, or a light honing oil, avail-
able from major oil distributors.

CAUTION: DO NOT use engine or transmission oil, mineral spirits, or kerosene.

3. Honing should be done by moving the hone up and down fast enough to get a crosshatch pattern (1). The hone

marks should INTERSECT at 50° to 60° for proper seating of rings (2).

4. A controlled hone motor speed between 200 and 300 RPM is necessary to obtain the proper crosshatch 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 crosshatch angle.

5. After honing, it 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 detergent. 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.

CLEANING

Thoroughly clean the oil pan and engine block gasket surfaces.

Use compressed air to clean out:

•

The galley at the oil filter adaptor hole.

•

The front and rear oil galley holes.

•

The feed holes for the crankshaft main bearings.

Once the block has been completely cleaned, apply Loctite PST pipe sealant with Teflon 592 to the threads of the
front and rear oil galley plugs. Tighten the 1/4 inch NPT plugs to 20 N·m (177 in. lbs.) torque. Tighten the 3/8 inch
NPT plugs to 27 N·m (240 in. lbs.) torque.

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ENGINE - 3.7L - SERVICE INFORMATION

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INSPECTION

1. It is mandatory to use a dial bore gauge to mea-

sure each cylinder bore diameter. To correctly
select the proper size piston, a cylinder bore
gauge, 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 at

three levels below top of bore. Start perpendicular
(across or at 90 degrees) to the axis of the crank-
shaft and then take two additional reading.

3. Measure the cylinder bore diameter crosswise to

the cylinder block near the top of the bore. Repeat
the measurement near the middle of the bore, then
repeat the measurement near the bottom of the
bore.

4. Determine taper by subtracting the smaller diame-

ter from the larger diameter.

5. Rotate measuring device 90° and repeat steps

above.

6. Determine out-of-roundness by comparing the dif-

ference between each measurement.

7. If cylinder bore taper does not exceed 0.025 mm (0.001 inch) and out-of-roundness does not exceed 0.025 mm

(0.001 inch), the cylinder bore can be honed. If the cylinder bore taper or out- of-round condition exceeds these
maximum limits, the cylinder block must be replaced. A slight amount of taper always exists in the cylinder bore
after the engine has been in use for a period of time.

DR/DH

ENGINE - 3.7L - SERVICE INFORMATION

9 - 2097