Timing Chain Tensioner

Replace the timing chain tensioner on a 2005 Dodge Viper 8.3L V10, requiring removal of front fascia components, cooling system access, and partial timing cover disassembly to access the tensioner assembly.

Warnings

Tools required

Parts

• Timing chain tensioner assembly × 1 — Use OEM specification
• Timing cover access gasket × 1 — Use OEM specification
• Tensioner cap crush washer × 1 — Use OEM specification
• Engine coolant (Zerex G-05 HOAT 50/50) × 1 — Mopar coolant or equivalent

Fluids

• Zerex G-05 HOAT 50/50 — 3 qt

Preparation

1. Park vehicle on level ground and engage parking brake.
2. Disconnect negative battery cable and secure away from terminal.
3. Allow engine to cool completely (minimum 2 hours after operation).
4. Raise front of vehicle and support securely on jack stands.
5. Remove engine cover if equipped.
6. Place drain pan under radiator drain cock.

Procedure

1. 1

   Drain Cooling System
   Open radiator drain cock at bottom of radiator and drain approximately 3 quarts of coolant into drain pan. This provides clearance to work without complete system drainage. Close drain cock when coolant level drops below upper radiator hose connection.
2. 2

   Remove Upper Radiator Hose
   Loosen hose clamps at radiator and thermostat housing connections on upper radiator hose. Twist hose to break seal, then remove hose and position aside. Allow any remaining coolant to drain into pan.
3. 3

   Remove Drive Belt
   Rotate belt tensioner clockwise using a breaker bar on the tensioner pulley bolt to release tension. Slide belt off pulleys and remove from engine bay. Inspect belt condition and replace if worn or cracked.
4. 4

   Remove Harmonic Balancer Bolt
   Use harmonic balancer holding tool or strap wrench to prevent crankshaft rotation. Remove harmonic balancer center bolt (verify socket size against OEM service data; high torque). Bolt is standard right-hand thread. Set bolt aside for reinstallation.
5. 5

   Remove Harmonic Balancer
   Install appropriate harmonic balancer puller onto balancer hub. Tighten puller center bolt to draw balancer off crankshaft snout. Do not hammer or pry on balancer. Once removed, inspect crankshaft key and keyway for damage.
6. 6

   Remove Timing Cover Access Section
   Consult OEM service data for the correct front timing cover removal procedure on the 8.3L V10; this engine does not use a separate bolt-on tensioner access panel and the full timing cover with its sealant/gasket interface must be addressed. Verify exact bolt count and pattern before proceeding.
   Torque spec

   Timing Cover Access Bolts12 Nm (9 lb-ft)
7. 7

   Inspect Timing Chain and Guides
   With access cover removed, visually inspect timing chain for wear, slack, and proper engagement on sprockets. Inspect chain guides and rails for wear grooves or cracks. Document condition before proceeding. Verify engine is at TDC cylinder 1 by observing timing marks if visible.
8. 8

   Remove Tensioner Cap
   Locate tensioner cap/plug on the tensioner assembly. Use appropriate socket to remove tensioner cap. Note presence of crush washer under cap and discard. This releases hydraulic pressure from tensioner.
   ⚠Tensioner may contain residual oil pressure. Have shop towel ready to catch any oil seepage.
   Torque spec

   Tensioner Cap/Plug30 Nm (22 lb-ft)
9. 9

   Remove Tensioner Housing Bolts
   Remove 2 tensioner housing bolts securing tensioner assembly to engine block. Support tensioner body as you remove final bolt, as tensioner is spring-loaded and will attempt to extend.
   ⚠Control tensioner during removal. Internal spring tension may cause sudden movement.
   Torque spec

   Tensioner Housing Bolts25 Nm (18 lb-ft)
10. 10

    Remove Tensioner Assembly
    Carefully withdraw tensioner assembly from engine block. Inspect mounting bore for debris or damage. Clean mounting surface with plastic scraper if needed. Inspect old tensioner for wear, scoring, or hydraulic fluid leakage.
11. 11

    Install New Tensioner Assembly
    Verify new tensioner is compressed and pinned or locked for installation per manufacturer instructions. Insert new tensioner into mounting bore, aligning bolt holes with block. Install 2 tensioner housing bolts finger-tight, ensuring tensioner seats fully against block.
    Torque spec

    Tensioner Housing Bolts25 Nm (18 lb-ft)
12. 12

    Torque Tensioner Housing Bolts
    Tighten tensioner housing bolts in a cross-pattern sequence to ensure even seating. Torque both bolts to specification. Verify tensioner is fully seated with no gaps between housing and block.
    Torque spec

    Tensioner Housing Bolts25 Nm (18 lb-ft)
13. 13

    Install Tensioner Cap
    Install new crush washer onto tensioner cap. Thread cap into tensioner housing and torque to specification. This completes tensioner hydraulic system seal.
    Torque spec

    Tensioner Cap/Plug30 Nm (22 lb-ft)
14. 14

    Release Tensioner Lock
    If new tensioner is equipped with shipping lock pin or clip, remove it now to allow tensioner to apply pressure to timing chain. Verify tensioner plunger extends and contacts chain guide or directly contacts chain per design. Timing chain should now have proper tension with no excessive slack.
15. 15

    Install Timing Cover Access Section
    Clean all old gasket material from timing cover access section and block mating surfaces using plastic scraper. Install new timing cover access gasket. Position access cover onto block, aligning all bolt holes. Install 6 timing cover access bolts finger-tight, then torque in a star pattern to specification.
    Torque spec

    Timing Cover Access Bolts12 Nm (9 lb-ft)
16. 16

    Install Harmonic Balancer
    Clean crankshaft snout and inner bore of harmonic balancer. Verify crankshaft key is properly seated in keyway. Align balancer keyway with crankshaft key and slide balancer onto snout. Balancer should slide on smoothly without force. Install a new harmonic balancer bolt and torque to OEM specification (verify whether a torque-plus-angle sequence and single-use bolt are required for this engine) using a holding tool to prevent rotation.
17. 17

    Install Drive Belt and Upper Radiator Hose
    Route drive belt around all pulleys per belt routing diagram. Rotate tensioner clockwise and slip belt onto final pulley. Release tensioner to apply proper tension. Reconnect upper radiator hose to radiator and thermostat housing. Position hose clamps properly and tighten securely.
18. 18

    Refill Cooling System
    Pour approximately 3 quarts of fresh Zerex G-05 HOAT 50/50 coolant into radiator or coolant reservoir until system reaches proper level. Leave radiator cap off for bleeding process.
19. 19

    Reconnect Battery and Initial Start
    Reconnect negative battery cable. Start engine and allow to idle. Monitor for coolant leaks at radiator hose connections and timing cover. Listen for unusual timing chain noise which could indicate tensioner issue. Engine should idle smoothly without rattling from timing chain area.
20. 20

    Bleed Cooling System
    With engine at idle, watch coolant level in radiator. Add coolant as level drops during bleeding. Run engine until thermostat opens and upper radiator hose becomes hot. Rev engine gently to 2000 RPM several times to purge air pockets. Top off coolant and install radiator cap. Allow engine to reach operating temperature and verify no leaks.

Reassembly

1. Reinstall engine cover if equipped.
2. Lower vehicle from jack stands.
3. Verify all tools and parts removed from engine bay.
4. Check coolant level after engine cools and top off if needed.
5. Dispose of used coolant according to local regulations.

Verification

• Start engine and verify smooth idle with no timing chain rattle or unusual noise from front cover area.
• Verify no coolant leaks at radiator hose connections, timing cover, or tensioner cap.
• Observe drive belt operation for proper tracking on all pulleys.
• Road test vehicle and listen for any abnormal engine noises during acceleration and deceleration.
• Recheck coolant level after first heat cycle and top off if necessary.
• Monitor for coolant leaks and timing noise for first 100 miles of operation.

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