Valve Springs - All

Complete removal and replacement of all valve springs on the 8.4L V10 engine, requiring cylinder head removal, valve train disassembly, and spring compression/installation.

Warnings

Tools required

Parts

• Valve springs (intake) × 10 — Use OEM specification
• Valve springs (exhaust) × 10 — Use OEM specification
• Valve spring retainers (intake) × 10 — Use OEM specification
• Valve spring retainers (exhaust) × 10 — Use OEM specification
• Valve stem seals × 20 — Use OEM specification
• Cylinder head gaskets × 2 — Use OEM specification
• Intake manifold gaskets × 1 — Use OEM specification
• Exhaust manifold gaskets × 2 — Use OEM specification
• Valve cover gaskets × 2 — Use OEM specification
• Cylinder head bolts (if TTY specification) × 1 — Verify if torque-to-yield
• Engine coolant (Mopar HOAT 50/50) × 1 — Use OEM specification
• Engine oil (0W-40 full synthetic) × 1 — Use OEM specification

Fluids

• coolant — 19 qt
• engine_oil — 11 qt

Preparation

1. Disconnect negative battery cable and secure away from battery post
2. Drain engine coolant completely into appropriate container by opening radiator petcock and removing lower radiator hose
3. Drain engine oil and remove oil filter
4. Remove engine cover panels and plastic trim pieces to access engine bay
5. Relieve fuel system pressure by removing fuel pump relay and cranking engine until it stalls
6. Document all electrical connector positions with photos before disconnection
7. Label all vacuum lines and coolant hoses before removal for proper reinstallation
8. Support engine weight with engine hoist or support fixture to allow clearance for cylinder head removal

Procedure

1. 1

   Remove intake manifold assembly
   Disconnect throttle body electrical connector and intake air temperature sensor. Remove intake air duct assembly. Disconnect fuel rail connectors and fuel lines, capturing any residual fuel. Remove throttle body mounting bolts. Disconnect all vacuum lines from intake manifold, including brake booster and PCV system. Remove intake manifold mounting bolts gradually and evenly, working from the outer bolts toward the center to relieve load evenly. Carefully lift intake manifold assembly clear of engine, noting any remaining hoses or harnesses. Remove and discard intake manifold gaskets.
2. 2

   Remove valve covers
   Disconnect ignition coil connectors on both cylinder banks. Remove ignition coils from each cylinder by removing mounting bolts. Disconnect any breather hoses or PCV connections from valve covers. Remove valve cover mounting bolts from both banks. Carefully pry valve covers loose if sealed with RTV and lift clear of cylinder heads. Remove and discard valve cover gaskets.
3. 3

   Remove exhaust manifolds
   Disconnect oxygen sensor electrical connectors on both banks. Remove exhaust manifold-to-catalytic converter flange bolts. Remove exhaust manifold heat shields if equipped. Remove exhaust manifold mounting bolts from both cylinder heads. Remove exhaust manifolds and discard gaskets. Inspect exhaust manifold studs for damage and replace if necessary.
4. 4

   Remove rocker arm assemblies
   Remove the individual rocker arm mounting bolts, loosening evenly. Carefully lift each rocker arm from its pedestal on the cylinder heads. Place rocker arms in an organized manner preserving position and orientation. Place assemblies in organized manner preserving position and orientation. Remove pushrods from each cylinder, keeping them organized by cylinder number and intake/exhaust position. Store pushrods vertically or in numbered rack to maintain original positions.
5. 5

   Remove cylinder heads
   Disconnect coolant temperature sensors and any remaining electrical connections to cylinder heads. Remove cylinder head bolt sequence using appropriate socket, following factory removal pattern (typically from outside working inward in crossing pattern). Remove cylinder head bolts and set aside for inspection. The cylinder head bolts are torque-to-yield and must be replaced with new bolts on reassembly. Carefully break cylinder head seal using plastic pry points at designated locations on head gasket surface. Lift cylinder heads straight up and off block, using assistance if needed due to weight. Place heads on clean padded surface with combustion chambers facing up. Remove and discard cylinder head gaskets.
6. 6

   Remove valve keepers and retainers
   Position valve spring compressor tool on first valve assembly, compressing spring sufficiently to access keepers. Using magnetic retrieval tool or small needle-nose pliers, carefully remove both valve keepers from valve stem groove. Slowly release valve spring compressor tension and remove tool. Remove valve spring retainer and valve spring from cylinder head. Remove valve stem seal by carefully prying or pulling from valve guide. Repeat process for all 20 valves (10 per head), maintaining strict organization of components by cylinder and position. Inspect each valve stem for wear or damage.
7. 7

   Inspect valve train components
   Thoroughly inspect all removed valve springs for cracks, corrosion, or signs of coil binding. Measure valve spring free height and installed height against factory specifications if specifications are available. Inspect valve stem seals for deterioration or damage. Examine valve retainers for wear or cracking. Check valve stems for scoring or excessive wear. Inspect cylinder head valve seats and valve faces for pitting, burning, or excessive wear. If any valves show damage, consider full valve job including lapping or machining. Clean all valve train component mounting surfaces on cylinder heads.
8. 8

   Install new valve stem seals
   Lubricate new valve stem seals with clean engine oil. Using appropriate seal installation tool or deep socket slightly larger than seal diameter, carefully press new valve stem seal onto valve guide until fully seated. Ensure seal is not cocked or damaged during installation. Apply light coat of clean engine oil to valve stem. Repeat for all 20 valve positions across both cylinder heads.
9. 9

   Install new valve springs and retainers
   Position new valve spring over valve stem, ensuring proper orientation (if springs are directional, closer-wound coils typically face cylinder head). Place new valve spring retainer on top of spring. Position valve spring compressor tool and compress spring sufficiently to expose valve stem keeper grooves. Install both valve keepers into valve stem groove, ensuring they seat properly in groove. Slowly release spring compressor while verifying keepers remain properly seated. After releasing compressor, tap valve stem tip lightly with plastic mallet to ensure keepers are fully seated. Repeat process for all 20 valves. After all springs are installed, visually verify all keepers are properly seated and springs are not cocked or misaligned.
10. 10

    Prepare cylinder head and block surfaces
    Using plastic gasket scraper, carefully remove all old gasket material from cylinder head mating surfaces on both heads. Remove all old gasket material from engine block deck surfaces. Clean surfaces thoroughly with brake cleaner or appropriate solvent. Inspect cylinder head surfaces for warping using straight edge and feeler gauge. Check engine block deck surface for damage or debris. Ensure all bolt holes in block are clean and free of oil or coolant. Thread-chase cylinder head bolt holes if necessary to ensure proper torque readings.
11. 11

    Install cylinder heads
    Position new cylinder head gaskets on engine block, ensuring correct orientation and alignment with dowel pins. Verify gaskets are correct left/right specific design. Carefully lower cylinder heads onto block, aligning with dowel pins and ensuring gaskets remain properly positioned. Install new cylinder head bolts (if TTY specification) or cleaned original bolts hand-tight in all positions. Following factory tightening sequence (typically from center outward in crossing pattern), torque cylinder head bolts in multiple stages as specified. Apply torque angle specifications if required by factory procedure. Verify all bolts reach final specification.
12. 12

    Install pushrods and rocker assemblies
    Install pushrods in their original positions, ensuring each pushrod seats properly in lifter socket below and rocker arm socket above. Apply clean engine oil to pushrod ends and rocker arm contact surfaces. Position each rocker arm onto its pedestal in correct orientation. Install rocker arm mounting bolts hand-tight. Torque rocker arm bolts to factory specification. Rotate engine manually two complete revolutions to verify proper valve train operation and no interference. Check that all rocker arms move freely and pushrods remain seated.
13. 13

    Install exhaust manifolds
    Clean exhaust manifold mounting surfaces on cylinder heads. Install new exhaust manifold gaskets. Position exhaust manifolds onto cylinder heads, aligning studs with manifold mounting holes. Install exhaust manifold mounting bolts or nuts and torque following factory sequence (typically from center outward). Reconnect exhaust manifolds to catalytic converter flanges with new hardware if needed. Reconnect oxygen sensor electrical connectors. Install exhaust manifold heat shields if equipped.
14. 14

    Install valve covers and intake manifold
    Install new valve cover gaskets onto cylinder heads or into valve cover grooves depending on design. Position valve covers onto cylinder heads and install mounting bolts hand-tight. Torque valve cover bolts following factory sequence and specification to avoid gasket distortion. Reinstall ignition coils and torque mounting bolts. Reconnect ignition coil electrical connectors. Position new intake manifold gaskets onto cylinder heads. Carefully lower intake manifold assembly onto engine, ensuring all gaskets remain properly positioned. Install intake manifold mounting bolts hand-tight. Torque intake manifold bolts following factory sequence (typically from center outward in crossing pattern). Reconnect all vacuum lines, coolant hoses, fuel lines, and electrical connections to intake manifold and throttle body. Reconnect fuel rail and fuel lines.
15. 15

    Complete engine reassembly and fill fluids
    Reinstall engine cover panels and trim pieces. Install new oil filter and fill engine with approximately 10 quarts of 0W-40 full synthetic engine oil, verifying level on the dipstick. Close coolant drain petcock and reconnect lower radiator hose. Fill cooling system with Mopar HOAT 50/50 coolant to factory-specified capacity through radiator and overflow reservoir, verifying level. Reconnect negative battery cable. Reinstall fuel pump relay. Prime fuel system by cycling ignition key to ON position (without cranking) several times, allowing fuel pump to run and pressurize the rail each time. Start engine and check immediately for any oil, coolant, or fuel leaks. Allow engine to reach operating temperature while monitoring for leaks and proper operation. Bleed cooling system of any air pockets by running engine with radiator cap off until thermostat opens, adding coolant as needed. This engine uses hydraulic lifters and requires no valve lash adjustment; no lash setting is necessary. Road test vehicle and verify proper engine operation under load.

Reassembly

1. Torque all fasteners to factory specifications in proper sequence
2. Replace all single-use gaskets and torque-to-yield bolts
3. Verify all electrical connectors are fully seated and locked
4. Ensure all vacuum lines and coolant hoses are properly routed and secured
5. Double-check that all valve keepers are properly seated before starting engine

Verification

• Start engine and verify no oil, coolant, or fuel leaks at all connection points
• Verify engine runs smoothly at idle with no unusual valve train noise
• Check for proper oil pressure indication on instrument cluster
• Verify coolant temperature reaches normal operating range without overheating
• Test drive vehicle and verify normal engine performance under acceleration and load
• Recheck all fluid levels after test drive and top off as necessary
• Inspect for any new leaks after engine reaches operating temperature

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