Variable Valve Timing Actuator

This procedure replaces the variable valve timing (VVT) actuator (cam phaser) on the 6.7L Cummins diesel engine, requiring removal of the front timing cover and timing components.

Warnings

Tools required

Parts

• VVT actuator (cam phaser) × 1 — Use OEM Mopar specification
• Timing cover gasket × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Front crankshaft seal × 1 — Use OEM specification
• Timing chain tensioner O-ring × 1 — Use OEM specification
• RTV silicone sealant (Mopar approved) × 1 — Use OEM specification

Fluids

• Mopar 5W-20 Synthetic Blend — 2 qt

Preparation

1. Ensure engine is completely cold
2. Disconnect both battery cables (negative first, then positive)
3. Raise and securely support vehicle on jack stands
4. Remove engine skid plate if equipped
5. Drain engine coolant into appropriate container by removing lower radiator hose
6. Drain engine oil and replace oil filter
7. Remove serpentine belt and tensioner
8. Remove cooling fan and shroud assembly
9. Remove air intake system and turbocharger inlet piping
10. Position drain pan under front of engine

Procedure

1. 1

   Remove valve cover
   Disconnect fuel injector harness connectors and set aside. Remove valve cover bolts in reverse sequence (outside to inside pattern). Carefully lift valve cover away from cylinder head. Clean any residual gasket material from mating surfaces.
2. 2

   Remove crankshaft pulley
   Remove crankshaft pulley bolt using impact wrench or holding tool to prevent crankshaft rotation. Use harmonic balancer puller to remove crankshaft pulley from front of crankshaft. Do not hammer or pry on pulley as this will damage it.
   ⚠This bolt is extremely tight (133 lb-ft). Ensure tool is properly seated to avoid damage.
3. 3

   Remove timing cover
   Remove all timing cover bolts, noting different lengths for proper reinstallation. The 8mm bolts require specific torque specifications. Carefully separate timing cover from engine block using non-marring pry points. Remove and discard timing cover gasket and front crankshaft seal.
4. 4

   Verify and mark timing positions
   Before loosening any timing components, verify timing marks on crankshaft gear and camshaft phaser align with marks on engine block and cylinder head. Take photos for reference. Install camshaft locking tool if available. Mark timing chain direction of rotation with paint marker.
   ⚠️Document all timing positions before proceeding. Incorrect reassembly will cause severe engine damage.
5. 5

   Release timing chain tension
   Locate timing chain tensioner on front of engine. Remove tensioner mounting bolt and carefully withdraw tensioner assembly. Note the position of tensioner shoe and guide. Keep tensioner clean and inspect for wear or damage.
6. 6

   Remove VVT solenoid
   Disconnect electrical connector from VVT solenoid located on front of cylinder head. Remove VVT solenoid mounting bolt and withdraw solenoid from cylinder head. Inspect solenoid screen for debris or blockage.
7. 7

   Remove cam phaser
   Use camshaft holding tool or large wrench on camshaft hex (located behind phaser) to prevent rotation. Remove cam phaser bolt from front of camshaft. Carefully pull cam phaser and timing chain forward off camshaft. Note relationship between timing chain and crankshaft sprocket for reassembly.
   ⚠Do not allow camshaft to rotate during removal. Hold firmly with appropriate tool.
8. 8

   Install new VVT actuator
   Inspect camshaft nose and oil passages for damage or debris. Install timing chain onto new cam phaser, ensuring chain direction matches previous marking. Align cam phaser timing marks with cylinder head marks and slide assembly onto camshaft. Verify timing marks on crankshaft sprocket still align correctly.
   ⚠️Triple-check all timing marks before proceeding. Camshaft mark must align with cylinder head mark, and crankshaft must be at TDC.
9. 9

   Install and torque cam phaser bolt
   Apply medium-strength threadlocker to cam phaser bolt threads as specified. Hold camshaft stationary using holding tool on hex. Install cam phaser bolt and torque to specification. Verify timing marks remain aligned after tightening.
   ℹ️Threadlocker application is critical. Bolt loosening will cause catastrophic failure.
10. 10

    Install timing chain tensioner
    Compress timing chain tensioner and install retaining pin or clip to hold in compressed position. Install new O-ring on tensioner body if applicable. Install tensioner into engine block, ensuring tensioner shoe engages timing chain properly. Install and torque tensioner bolt, then remove retaining pin to activate tensioner. Verify chain has proper tension.
    ⚠Tensioner must be compressed and pinned before installation to prevent chain jumping.
11. 11

    Install VVT solenoid
    Clean VVT solenoid mounting area and inspect screen in cylinder head oil passage. Install VVT solenoid with new O-ring if required. Torque mounting bolt to specification and reconnect electrical connector.
12. 12

    Reinstall timing cover
    Install new front crankshaft seal into timing cover using seal driver. Clean all gasket surfaces thoroughly. Apply thin bead of RTV sealant to corners where cover meets engine block and oil pan. Install new timing cover gasket and position timing cover onto engine. Install all timing cover bolts finger-tight, then torque 8mm bolts to specification in proper sequence (refer to service manual for sequence pattern).
13. 13

    Reinstall crankshaft pulley
    Clean crankshaft snout and inside of pulley hub. Install crankshaft pulley onto crankshaft, ensuring it seats fully. Install crankshaft pulley bolt and torque to specification using impact wrench or holding tool. Verify pulley does not wobble and is seated completely.
14. 14

    Reinstall valve cover
    Install new valve cover gasket onto valve cover. Position valve cover onto cylinder head, ensuring injector harness routing is correct. Install valve cover bolts and torque in proper sequence (center outward pattern) to specification. Reconnect all injector harness connectors.

Reassembly

1. Reinstall turbocharger inlet piping and air intake system
2. Reinstall cooling fan and shroud assembly
3. Reinstall serpentine belt and tensioner, ensuring proper belt routing
4. Reinstall engine skid plate if equipped
5. Refill engine with proper quantity and specification of engine oil (13 quarts 5W-20)
6. Refill cooling system with Mopar OAT Purple coolant and bleed air from system
7. Reconnect battery cables (positive first, then negative)

Verification

• Before starting engine, manually rotate crankshaft two complete revolutions and verify all timing marks realign correctly
• Check for any unusual resistance while rotating crankshaft by hand
• Start engine and listen for any abnormal timing-related noises (rattling, ticking)
• Monitor oil pressure gauge - should rise to normal within 5 seconds
• Check for oil and coolant leaks around timing cover and valve cover
• Verify no diagnostic trouble codes related to VVT system using scan tool
• Test drive vehicle and verify normal engine performance, especially during acceleration
• Monitor for proper engine oil pressure during operation and VVT system operation with scan tool
• Recheck all fastener torques after first test drive

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