Dodge Dakota (R1). Manual — part 481

ENGINE OIL CHANGE

Change engine oil at mileage and time intervals

described in the Maintenance Schedule. This infor-
mation can be found in the owner’s manual.

TO CHANGE ENGINE OIL

Run engine until achieving normal operating tem-

perature.

(1) Position the vehicle on a level surface and turn

engine off.

(2) Hoist vehicle.
(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. Inspect drain plug threads for
stretching or other damage. Replace drain plug and
gasket if damaged.

(6) Install drain plug in crankcase.
(7) Change oil filter (Refer to 9 - ENGINE/LUBRI-

CATION/OIL FILTER - REMOVAL).

(8) Lower vehicle and fill crankcase with specified

type (Refer to LUBRICATION & MAINTENANCE/
FLUID TYPES - DESCRIPTION) and amount of
engine oil (Refer to LUBRICATION & MAINTE-
NANCE - SPECIFICATIONS).

(9) Install oil fill cap.
(10) Start engine and inspect for leaks.
(11) Stop engine and inspect oil level.

OIL FILTER

REMOVAL

All engines are equipped with a high quality full-

flow, disposable type oil filter. DaimlerChrysler Cor-
poration recommends a Mopar

t or equivalent oil

filter be used.

(1) Position a drain pan under the oil filter.
(2) Using a suitable oil filter wrench loosen filter.
(3) Rotate the oil filter counterclockwise to remove

it from the cylinder block oil filter boss (Fig. 62).

(4) When filter separates from adapter nipple, tip

gasket end upward to minimize oil spill. Remove fil-
ter from vehicle.

(5) With a wiping cloth, clean the gasket sealing

surface (Fig. 70) of oil and grime.

(6) Install new filter (Refer to 9 - ENGINE/LUBRI-

CATION/OIL FILTER - INSTALLATION).

INSTALLATION

(1) Lightly lubricate oil filter gasket with engine

oil or chassis grease.

(2) Thread filter onto adapter nipple. When gasket

makes contact with sealing surface, (Fig. 63) hand
tighten filter one full turn, do not over tighten.

(3) Add oil (Refer to 9 - ENGINE/LUBRICATION/

OIL - STANDARD PROCEDURE).

OIL PAN

REMOVAL

(1) Disconnect the negative cable from the battery.
(2) Remove engine oil dipstick.
(3) Raise vehicle.
(4) Drain engine oil.
(5) Remove exhaust pipe.
(6) Remove left engine to transmission strut.
(7) Loosen the right side engine support bracket

cushion through-bolt nut and raise the engine
slightly. Remove oil pan by sliding backward and out.

(8) Remove the one-piece gasket.

CLEANING

Clean the block and pan gasket surfaces.
Trim or remove excess sealant film in the rear

main cap oil pan gasket groove. DO NOT remove
the sealant inside the rear main cap slots.

Fig. 62 Oil Filter Removal—Typical

1 - ENGINE OIL FILTER
2 - OIL FILTER WRENCH

Fig. 63 Oil Filter Sealing Surface—Typical

1 - SEALING SURFACE
2 - RUBBER GASKET
3 - OIL FILTER

9 - 112

ENGINE 3.9L

AN

OIL (Continued)

If present, trim excess sealant from inside the

engine.

Clean oil pan in solvent and wipe dry with a clean

cloth.

Clean oil screen and pipe thoroughly in clean sol-

vent. Inspect condition of screen.

INSPECTION

Inspect oil drain plug and plug hole for stripped or

damaged threads. Repair as necessary.

Inspect oil pan mounting flange for bends or distor-

tion. Straighten flange, if necessary.

INSTALLATION

(1) Clean the block and pan gasket surfaces.
(2) Fabricate four alignment dowels from 5/16 X 1

1/2 inch bolts. Cut the head off the bolts and cut a
slot into the top of the dowel. This will allow easier
installation and removal with a screwdriver (Fig. 64)
.

(3) Install the dowels in the cylinder block (Fig.

65) .

(4) Apply small amount of Mopar

t Silicone Rubber

Adhesive Sealant, or equivalent, in the corner of the
cap and the cylinder block.

(5) Slide the one-piece gasket over the dowels and

onto the block.

(6) Position the oil pan over the dowels and onto

the gasket.

(7) Install the oil pan bolts. Tighten the bolts to 24

N·m (215 in. lbs.) torque.

(8) Remove the dowels. Install the remaining oil

pan bolts. Tighten these bolts to 24 N·m (215 in. lbs.)
torque.

(9) Lower the engine into the support cushion

brackets and tighten the through-bolt nut to the
proper torque.

(10) Install the drain plug. Tighten drain plug to

34 N·m (27 ft. lbs.) torque.

(11) Install the engine to transmission strut.
(12) Install exhaust pipe.
(13) Lower vehicle.
(14) Install dipstick.
(15) Connect the negative cable to the battery.
(16) Fill crankcase with oil to proper level.

OIL PUMP

REMOVAL

(1) Remove the oil pan (Refer to 9 - ENGINE/LU-

BRICATION/OIL PAN - REMOVAL).

(2) Remove the oil pump from rear main bearing

cap.

DISASSEMBLY

(1) Remove the relief valve as follows:

(a) Remove cotter pin. Drill a 3.175 mm (1/8 in.)

hole into the relief valve retainer cap and insert a
self-threading sheet metal screw into cap.

(b) Clamp screw into a vise and while support-

ing oil pump, remove cap by tapping pump body
using a soft hammer. Discard retainer cap and
remove spring and relief valve (Fig. 66) .
(2) Remove oil pump cover (Fig. 67) .
(3) Remove pump outer rotor and inner rotor with

shaft (Fig. 67) .

(4) Wash all parts in a suitable solvent and inspect

carefully for damage or wear.

Fig. 64 Fabrication of Alignment Dowels

1 - 5/16” X 1½” BOLT
2 - DOWEL
3 - SLOT

Fig. 65 Position of Dowels in Cylinder Block

1 - DOWEL
2 - DOWEL
3 - DOWEL
4 - DOWEL

AN

ENGINE 3.9L

9 - 113

OIL PAN (Continued)

CLEANING

Use only mild solvents to clean the oil pump. Do

not use any abrasive material to clean the oil pump
housing or rotors.

INSPECTION

Mating surface of the oil pump cover should be

smooth. Replace pump assembly if cover is scratched
or grooved.

Lay a straightedge across the pump cover surface

(Fig. 68) . If a 0.038 mm (0.0015 in.) feeler gauge can
be inserted between cover and straightedge, pump
assembly should be replaced.

Measure thickness and diameter of outer rotor. If

outer rotor thickness measures 20.9 mm (0.825 in.)
or less, or if the diameter is 62.7 mm (2.469 in.) or
less, replace outer rotor (Fig. 69) .

Fig. 66 Oil Pressure Relief Valve

1 - OIL PUMP ASSEMBLY
2 - COTTER PIN
3 - RELIEF VALVE
4 - RETAINER CAP
5 - SPRING

Fig. 67 Oil Pump

1 - INNER ROTOR AND SHAFT
2 - BODY
3 - DISTRIBUTOR DRIVESHAFT (REFERENCE)
4 - COTTER PIN
5 - RETAINER CAP
6 - SPRING
7 - RELIEF VALVE
8 - LARGE CHAMFERED EDGE
9 - BOLT
10 - COVER
11 - OUTER ROTOR

Fig. 68 Checking Oil Pump Cover Flatness

1 - COVER
2 - STRAIGHT EDGE
3 - FEELER GAUGE

Fig. 69 Measuring Outer Rotor Thickness

9 - 114

ENGINE 3.9L

AN

OIL PUMP (Continued)

If inner rotor measures 20.9 mm (0.825 in.) or less,

replace inner rotor and shaft assembly (Fig. 70) .

Slide outer rotor into pump body. Press rotor to the

side

with

your

fingers

and

measure

clearance

between rotor and pump body (Fig. 71) . If clearance
is 0.356 mm (0.014 in.) or more, replace oil pump
assembly.

Install inner rotor and shaft into pump body. If

clearance between inner and outer rotors is 0.203
mm (0.008 in.) or more, replace shaft and both rotors
(Fig. 72) .

Place a straightedge across the face of the pump,

between bolt holes. If a feeler gauge of 0.102 mm
(0.004 in.) or more can be inserted between rotors
and the straightedge, replace pump assembly (Fig.
73) .

Inspect oil pressure relief valve plunger for scoring

and free operation in its bore. Small marks may be
removed with 400-grit wet or dry sandpaper.

The relief valve spring has a free length of approx-

imately 49.5 mm (1.95 in.). The spring should test
between 19.5 and 20.5 pounds when compressed to
34 mm (1-11/32 in.). Replace spring that fails to meet
these specifications (Fig. 74) .

If oil pressure was low and pump is within specifi-

cations, inspect for worn engine bearings or other
reasons for oil pressure loss.

ASSEMBLY

(1) Install pump rotors and shaft, using new parts

as required.

(2) Position the oil pump cover onto the pump

body. Tighten cover bolts to 11 N·m (95 in. lbs.)
torque.

Fig. 70 Measuring Inner Rotor Thickness

Fig. 71 Measuring Outer Rotor Clearance in

Housing

1 - PUMP BODY
2 - OUTER ROTOR
3 - FEELER GAUGE

Fig. 72 Measuring Clearance Between Rotors

1 - OUTER ROTOR
2 - FEELER GAUGE
3 - INNER ROTOR

Fig. 73 Measuring Clearance Over Rotors

1 - STRAIGHT EDGE
2 - FEELER GAUGE

AN

ENGINE 3.9L

9 - 115

OIL PUMP (Continued)