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This page last updated: April 20, 2014

WJ Serpentine belts

Under normal use, the serpentine drive belt should be inspected at around 45,000 miles or after 3-4 years of service. If not replaced at this time, the belt should be checked each additional year or 15,000 miles. Under severe and off-road conditions inspect the belt annually. When diagnosing serpentine drive belts, small cracks that run across ribbed surface of belt from rib to rib are considered normal. These are not a reason to replace the belt. However, cracks running lengthwise along a rib (not across) are not normal. Any belt with cracks running lengthwise along a rib should be replaced. Also replace the belt if it has excessive wear, frayed cords or severe glazing.

Warning: Spring tensioners should not be disassembled because of high spring tension. The tensioner unit is serviced as an assembly.

4.0 I-6 Engine:

serpentine belt 4.0L
serpentine belt 4.0L

4.0 Engine belt routing and tensioner release location

4.7 V-8 Engine:

serpentine belt 4.7L
serpentine belt 4.7L

4.7 Engine belt routing and tensioner release location

Belt removal and replacement:

NOTE: If anything differs between the pictures shown above and the Belt Routing Label (located in the engine compartment), use the schematic on the Routing Label.


1. Disconnect negative battery cable from battery.

2. Using a 15mm socket wrench (1/2" drive breaker bar or ratchet for the 4.0), rotate belt tensioner clockwise until it contacts its stop. Remove belt, then slowly rotate the tensioner into the freearm stop position.

3. Install new belt. Route the belt around all pulleys except the idler pulley. Rotate the tensioner arm clockwise until it contacts its stop position. Route the belt around the idler and slowly let the tensioner rotate into the belt. Make sure the belt is seated onto all pulleys. Inspect the entire belt path to make sure it is seated correctly on the pulleys.

4. With the drive belt installed, inspect the belt wear indicator (see diagram below):

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.

On 4.0L Engines, the indicator mark must be between the minimum and maximum marks. The tensioner arm has three marks. Upon installation of a new belt, the double line marks close to each other should be very close to the mark on the base. The belt should be replaced if the single line mark lines up with the mark on the base.

serpentine belt 4.0L

Serpentine belts
EnginePart #Model YearMSRP
4.0L P/N 4854033
superseded by:
P/N 4854033AB
1999-2004 $65.50
4.7L P/N 53032037AC
superseded by:
P/N 53032037AI
superseded by:
P/N 53032037AK
superseded by:
P/N 5135745AA
1999-2003 $62.35
4.7L P/N 53032037AJ
superseded by:
P/N 53013905AA
2004 $28.70
Belt tensioner assembly
Note: Replace belt when replacing tensioner
4.0L P/N 4854089AB

(Tighten bolt to 250 in. lbs. (28 Nm)

1999-2004 $102.00
4.7L P/N 53030958
superseded by:
P/N 53030958AC

(Tighten bolt to 30 ft. lbs. (41 Nm)

1999-2004 $66.70
Part numbers in bold are the recommended and/or latest part available

(Note: prices listed are for reference purposes only and may vary by dealer. MSRP prices are current as of April 2014. Parts are not available from this web site)

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