Dodge Dakota (R1). Manual — part 252
It is not necessary to adjust belt tension on the
4.7L engine. These engines are equipped with an
automatic belt tensioner (Fig. 4). The tensioner main-
tains correct belt tension at all times. Due to use of
this belt tensioner, do not attempt to use a belt ten-
sion gauge on 4.7L engines.
OPERATION
The automatic belt tensioner maintains belt ten-
sion by using internal spring pressure, a pivoting
arm and pulley to press against the drive belt.
REMOVAL
On 4.7L engines, the tensioner is equipped
with an indexing tang on back of tensioner and
an indexing stop on tensioner housing. If a new
belt is being installed, tang must be within
approximately 24 mm (.94 inches) of indexing
stop. Belt is considered new if it has been used
15 minutes or less.
If the above specification cannot be met, check for:
• The wrong belt being installed (incorrect length/
width)
• Worn bearings on an engine accessory (A/C com-
pressor, power steering pump, water pump, idler pul-
ley or generator)
• A pulley on an engine accessory being loose
• Misalignment of an engine accessory
• Belt incorrectly routed.
NOTE: A used belt should be replaced if tensioner
indexing arrow has moved to the minmum tension
indicator. Tensioner travel stops at this point.
(1) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY
DRIVE/DRIVE
BELTS
-
REMOVAL).
(2) Remove tensioner assembly from mounting
bracket (Fig. 5).
WARNING: BECAUSE OF HIGH SPRING PRES-
SURE, DO NOT ATTEMPT TO DISASSEMBLE AUTO-
MATIC TENSIONER. UNIT IS SERVICED AS AN
ASSEMBLY EXCEPT FOR PULLEY ON TENSIONER.
(3) Remove pulley bolt. Remove pulley from ten-
sioner.
INSTALLATION
(1) Install pulley and pulley bolt to tensioner.
Tighten bolt to 61 N·m (45 ft. lbs.) torque.
(2) An indexing slot is located on back of tensioner.
Align this slot to the head of the bolt on the front
cover. Install the mounting bolt. Tighten bolt to 41
N·m (30 ft. lbs.).
(3) Install accessory drive belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(4) Check belt indexing marks (Fig. 4).
Fig. 4 Automatic Belt Tensioner
1 - AUTOMATIC TENSIONER ASSEMBLY
Fig. 5 Automatic Belt Tensioner—4.7L Engine
1 - TIMING CHAIN COVER
2 - BOLT TORQUE TO 41 N·m (30 FT LBS)
3 - AUTOMATIC BELT TENSIONER
7 - 20
ACCESSORY DRIVE
AN
BELT TENSIONERS - 4.7L (Continued)
DRIVE BELTS - 2.5L
DIAGNOSIS AND TESTING—ACCESSORY
DRIVE BELT
VISUAL DIAGNOSIS
When diagnosing serpentine accessory drive belts,
small cracks that run across the ribbed surface of the
belt from rib to rib (Fig. 6), are considered normal.
These are not a reason to replace the belt. However,
cracks running along a rib (not across) are not nor-
mal. Any belt with cracks running along a rib must
be replaced (Fig. 6). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Refer to ACCESSORY DRIVE BELT DIAGNOSIS
CHART for further belt diagnosis.
NOISE DIAGNOSIS
Noises generated by the accessory drive belt are
most noticeable at idle. Before replacing a belt to
resolve a noise condition, inspect all of the accessory
drive pulleys for alignment, glazing, or excessive end
play.
ACCESSORY DRIVE BELT DIAGNOSIS CHART
CONDITION
POSSIBLE CAUSES
CORRECTION
RIB CHUNKING (One or more
ribs has separated from belt
body)
1. Foreign objects imbedded in pulley
grooves.
1. Remove foreign objects from
pulley grooves. Replace belt.
2. Installation damage
2. Replace belt
RIB OR BELT WEAR
1. Pulley misaligned
1. Align pulley(s)
2. Abrasive environment
2. Clean pulley(s). Replace belt if
necessary
3. Rusted pulley(s)
3. Clean rust from pulley(s)
4. Sharp or jagged pulley groove tips
4. Replace pulley. Inspect belt.
5. Belt rubber deteriorated
5. Replace belt
BELT SLIPS
1. Belt slipping because of insufficient
tension
1. Inspect/Replace tensioner if
necessary
2. Belt or pulley exposed to substance
that has reduced friction (belt
dressing, oil, ethylene glycol)
2. Replace belt and clean pulleys
3. Driven component bearing failure
(seizure)
3. Replace faulty component or
bearing
4. Belt glazed or hardened from heat
and excessive slippage
4. Replace belt.
Fig. 6 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
AN
ACCESSORY DRIVE
7 - 21
CONDITION
POSSIBLE CAUSES
CORRECTION
LONGITUDAL BELT CRACKING
1. Belt has mistracked from pulley
groove
1. Replace belt
2. Pulley groove tip has worn away
rubber to tensile member
2. Replace belt
9
GROOVE JUMPING
9
(Belt does not maintain correct
position on pulley)
1. Incorrect belt tension
1. Inspect/Replace tensioner if
necessary
2. Pulley(s) not within design tolerance
2. Replace pulley(s)
3. Foreign object(s) in grooves
3. Remove foreign objects from
grooves
4. Pulley misalignment
4. Align component
5. Belt cordline is broken
5. Replace belt
BELT BROKEN
(Note: Identify and correct
problem before new belt is
installed)
1. Incorrect belt tension
1. Replace Inspect/Replace
tensioner if necessary
2. Tensile member damaged during
belt installation
2. Replace belt
3. Severe misalignment
3. Align pulley(s)
4. Bracket, pulley, or bearing failure
4. Replace defective component and
belt
NOISE
(Objectionable squeal, squeak,
or rumble is heard or felt while
drive belt is in operation)
1. Incorrect belt tension
1. Inspect/Replace tensioner if
necessary
2. Bearing noise
2. Locate and repair
3. Belt misalignment
3. Align belt/pulley(s)
4. Belt to pulley mismatch
4. Install correct belt
5. Driven component induced vibration
5. Locate defective driven
component and repair
TENSION SHEETING FABRIC
FAILURE
(Woven fabric on outside,
circumference of belt has
cracked or separated from body
of belt)
1. Tension sheeting contacting
stationary object
1. Correct rubbing condition
2. Excessive heat causing woven
fabric to age
2. Replace belt
3. Tension sheeting splice has
fractured
3. Replace belt
CORD EDGE FAILURE
(Tensile member exposed at
edges of belt or separated from
belt body)
1. Incorrect belt tension
1. Inspect/Replace tensioner if
necessary
2. Belt contacting stationary object
2. Replace belt
3. Pulley(s) out of tolerance
3. Replace pulley
4. Insufficient adhesion between
tensile member and rubber matrix
4. Replace belt
7 - 22
ACCESSORY DRIVE
AN
DRIVE BELTS - 2.5L (Continued)
REMOVAL
Correct drive belt tension is required to ensure
optimum performance of the belt driven engine acces-
sories. There are different types of adjustment
gauges for checking either a serpentine or a V-type
belt. Refer to the instructions supplied with the
gauge. Use the correct gauge when checking belt ten-
sion. Place gauge in the middle of the section of belt
being tested (between two pulleys) to check tension.
Do not allow the gauge (or gauge adapter) to contact
anything but the belt.
Belt tension is adjusted at the power steering
pump bracket and idler pulley assembly.
(1) Disconnect negative battery cable from battery.
(2) Loosen idler pulley bolt (Fig. 7).
(3) Loosen tension adjusting bolt (Fig. 7) and
remove accessory drive belt.
BELT SCHEMATICS
The belt routing schematics are published from the
latest information available at the time of publica-
tion. Vehicles not equipped with Power Steering have
an idler pulley in place of the power steering pump
pulley. If anything differs between these sche-
matics and the Belt Routing Label, use the
schematics on Belt Routing Label. This label is
located in the engine compartment.
Refer to (Fig. 8) or (Fig. 9) for correct belt routing,
or refer to Belt Routing Label located in the vehicle
engine compartment.
Fig. 7 Power Steering Pump Bracket and Idler
Pulley—2.5L
1 - ADJUSTMENT BOLT
2 - IDLER BOLT/ANCHOR BOLT
3 - ACCESSORY DRIVE BELT
Fig. 8 2.5L – With A/C
1 - GENERATOR PULLEY
2 - AIR CONDITIONER COMPRESSOR PULLEY
3 - IDLER PULLEY
4 - POWER STEERING PUMP PULLEY
5 - WATER PUMP AND FAN PULLEY
6 - IDLER PULLEY
7 - CRANKSHAFT PULLEY
Fig. 9 2.5L Engines – Without A/C
1 - GENERATOR PULLEY
2 - IDLER PULLEY
3 - WATER PUMP AND FAN PULLEY
4 - POWER STEERING PUMP PULLEY
5 - IDLER PULLEY
6 - CRANKSHAFT PULLEY
AN
ACCESSORY DRIVE
7 - 23
DRIVE BELTS - 2.5L (Continued)
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