Main Bearings

Complete replacement of main bearing shells and inspection of crankshaft journals, requiring engine removal and full disassembly of the lower end of the 8.4L V10 engine.

Warnings

Tools required

Parts

• Main bearing set (upper and lower shells) × 1 — Use OEM Mopar specification for 8.4L V10
• Thrust bearing set × 1 — Use OEM Mopar specification for 8.4L V10
• Main cap bolts (if torque-to-yield) × 1 — Verify with dealer if reusable
• Rear main seal × 1 — Use OEM Mopar specification
• Front crankshaft seal × 1 — Use OEM Mopar specification
• Oil pan gasket × 1 — Use OEM Mopar specification
• Windage tray gasket/seals (if equipped) × 1 — Use OEM specification
• Engine oil and filter × 1 — 0W-40 full synthetic
• Coolant × 1 — Mopar HOAT 50/50
• RTV silicone sealant (high-temp) × 1 — Mopar Engine RTV or equivalent
• Engine assembly lubricant × 1 — Moly-based assembly lube

Fluids

• 0W-40 full synthetic engine oil — 11 qt
• Mopar HOAT coolant 50/50 — 19 qt

Preparation

1. Ensure vehicle is on level ground with parking brake applied and transmission in park/neutral
2. Disconnect negative battery cable and isolate from battery terminal
3. Allow engine to cool completely (minimum 4 hours after running)
4. Remove engine cover panels
5. Drain engine oil completely and remove oil filter
6. Drain cooling system completely from radiator and block drains
7. Relieve fuel system pressure by removing fuel pump fuse and cranking engine until it stalls
8. Photograph and label all electrical connectors, vacuum lines, and hose routing for reassembly reference
9. Place fender covers to protect paint during engine removal

Procedure

1. 1

   Remove hood and front accessories
   With an assistant, remove hood by unbolting hinges at cowl. Mark hinge positions for reinstallation alignment. Remove front fascia if needed for radiator clearance. Disconnect upper and lower radiator hoses, transmission cooler lines (if automatic), and remove radiator support/radiator assembly. Remove drive belts, then unbolt and remove alternator, A/C compressor (do not disconnect refrigerant lines, support aside), and power steering pump (support aside with lines attached).
2. 2

   Disconnect engine electrical and fuel systems
   Disconnect all engine harness connectors including PCM connectors, injector harness, coil pack connectors, cam/crank sensors, oxygen sensors, and ground straps. Label each connection. Disconnect throttle body linkage and cruise control cable if equipped. Disconnect fuel supply and return lines at fuel rail using quick-disconnect tool. Cap open fuel lines to prevent contamination.
3. 3

   Remove intake and exhaust systems
   Remove complete intake manifold assembly including throttle body and fuel rails. Disconnect exhaust system at manifold flanges or remove complete exhaust manifolds with catalytic converters depending on clearance requirements. On Viper, side-exit exhaust typically requires disconnection at slip joints or removal of complete pipes.
4. 4

   Separate transmission from engine
   Support transmission with transmission jack. Remove transmission-to-engine bellhousing bolts (count and note locations as bolt lengths vary). On manual transmission, remove clutch hydraulic line at bellhousing. Carefully separate transmission rearward ensuring input shaft clears clutch disc and pressure plate. Lower transmission and remove from under vehicle or leave supported if engine will be lifted out from above.
5. 5

   Remove engine mounts and extract engine
   Attach engine hoist with lifting chains to factory lift points or secure lifting brackets to cylinder heads. Take up slack in hoist. Remove engine mount through-bolts at frame mounts (typically 2 per side). Verify all hoses, wires, and brackets are disconnected. Carefully lift engine while checking for any remaining connections. Tilt engine as needed to clear firewall and frame rails. Once clear of vehicle, transfer engine to engine stand by bolting stand adapter to bellhousing bolt pattern.
6. 6

   Remove external engine components
   With engine on stand, remove remaining accessories: starter motor, flywheel/flexplate (use flywheel holding tool and remove bolts), front harmonic balancer using puller (do not hammer), timing chain cover, timing chain and gears, cylinder heads (if access to main caps requires), oil pump pickup tube, and windage tray if equipped. Remove all items that interfere with oil pan or main cap access.
7. 7

   Remove oil pan and inspect lower end
   Remove oil pan bolts (count approximately 18-20 bolts around perimeter). Carefully pry pan free using plastic scraper at gasket seams, not at machined sealing surfaces. Inspect connecting rod bearings visually for scoring, discoloration, or wear patterns indicating problems. Check for metal debris in pan. If rod bearings show damage, main bearings are likely also damaged. Clean all old gasket material from pan and block sealing surfaces.
8. 8

   Mark and remove main bearing caps
   Using permanent marker or number stamps, clearly mark each main bearing cap with its position number (1-5 from front to rear) and orientation arrow pointing toward front of engine. Main caps are machined in place and must return to exact original position. Check for existing factory marks. Remove main cap bolts in reverse of tightening sequence (typically loosening outer bolts first, working toward center in multiple passes). Carefully lift main caps straight up without cocking sideways. Keep caps in order.
9. 9

   Remove bearing shells and inspect crankshaft
   Remove upper and lower bearing shells from main saddles and caps. Note thrust bearing location (typically center main, #3). Keep bearings in order if inspection is needed. With bearings removed, carefully lift crankshaft straight up out of block using assistance due to weight. Inspect all main journal surfaces for scoring, discoloration, out-of-round wear, or damage. Using micrometer, measure each journal diameter at multiple points (measure at 90-degree intervals and at several points along journal length). Compare measurements to factory specification. Journals must be within 0.001 inch of specification and show no taper or out-of-round exceeding 0.0005 inch. If journals are scored or out-of-spec, crankshaft requires grinding by machine shop.
10. 10

    Inspect main bearing saddles in block
    Clean all bearing saddles thoroughly with brake cleaner and lint-free rags. Inspect saddle surfaces for scoring, galling, or damage. Check oil passages in block are clear by spraying brake cleaner through passages. If dial bore gauge is available, measure saddle bore diameter and alignment. Any saddle damage requires machine shop line-boring or align-honing. Clean crankshaft journals with brake cleaner and verify all oil passages in crankshaft are clear.
11. 11

    Install new upper bearing shells
    Wipe bearing saddles clean and dry. Install new upper bearing shells (with oil holes) into block saddles. Bearing tabs must engage notches in saddles. Do not file or force bearings. Apply thin coat of assembly lubricant to bearing surfaces. Ensure thrust bearing halves (wider bearings) are installed in correct main position, typically center main (#3). Verify oil holes in bearings align with oil passages in block.
12. 12

    Install crankshaft and verify bearing clearance
    Carefully lower crankshaft into bearing saddles, aligning all journals. Install lower bearing shells into main caps (shells without oil holes go in caps). Apply assembly lubricant to lower bearing surfaces. Before final installation, verify bearing clearance using Plastigage: place strip of Plastigage across each journal, install cap and torque to specification, then remove cap and measure crushed Plastigage width against package scale. Clearance should be 0.001-0.003 inches for most applications. Record clearances for all main bearings. If clearance is tight (under 0.001) or excessive (over 0.004), verify bearing size and journal diameter.
13. 13

    Install main bearing caps and torque to specification
    After verifying clearances, remove Plastigage residue completely. Apply fresh assembly lubricant to all bearings. Install main caps in correct positions with orientation marks facing forward. Install main cap bolts and tighten following factory sequence and specification. Typical sequence starts at center main and works outward alternately. First stage torque is typically 20-25 ft-lbs, followed by final torque of 50-65 ft-lbs, then additional angle torque of 60-90 degrees. After torquing, verify crankshaft rotates smoothly by hand. Any binding indicates problem with bearing clearance, cap alignment, or thrust bearing position. Check crankshaft endplay using dial indicator or feeler gauge between thrust bearing and crankshaft thrust surface. Typical spec is 0.004-0.012 inches.
14. 14

    Install rear main seal and oil pump components
    Install new rear main seal using seal driver or appropriate socket to press seal squarely into bore. Seal lips face toward engine interior. Apply small amount of RTV to outer edge of seal housing if required by design. Install oil pump pickup tube with new O-ring, ensuring screen is positioned correctly in oil pan area and tube is torqued to specification. Install windage tray if equipped, using new gaskets or seals.
15. 15

    Install oil pan and prepare for engine assembly
    Clean oil pan and block sealing surfaces completely. Apply thin bead of RTV silicone to block sealing surface following factory pattern (typically 1/8 inch bead inboard of bolt holes, with beads around timing cover junction and rear main seal area). Install oil pan gasket if design uses formed gasket in addition to RTV. Install oil pan and start all bolts by hand. Torque pan bolts in crisscross pattern from center outward to specification (typically 10-15 ft-lbs). Allow RTV to cure per manufacturer instructions (typically 1 hour minimum before oil fill, 24 hours before full operation). Install front crankshaft seal, then reinstall timing components (chain, gears, cover), cylinder heads if removed, and all external accessories in reverse order of removal.
16. 16

    Install engine into vehicle
    With all external components reinstalled on engine, reverse engine removal procedure. Use hoist to lower engine into engine bay, aligning with transmission bellhousing (rotate crankshaft as needed to align input shaft splines). Install engine mount bolts and torque to specification. Install all bellhousing bolts and torque in star pattern. Reconnect exhaust system, intake manifold, all electrical connectors, fuel lines, cooling system hoses, and drive belts. Reinstall radiator assembly and hood.
17. 17

    Fill fluids and perform initial startup
    Install new oil filter and fill engine with 11 quarts of 0W-40 full synthetic oil. Fill cooling system with 19 quarts of Mopar HOAT 50/50 coolant. Reconnect battery. Before starting, disable ignition and crank engine with starter for 15-20 seconds to prime oil system and build oil pressure. Verify oil pressure gauge shows pressure during cranking. Enable ignition and start engine. Check immediately for oil pressure (should show pressure within 2-3 seconds). Listen for abnormal noises. Check for leaks around oil pan, rear main seal, and all connections. Allow engine to warm to operating temperature while monitoring temperature gauge and checking for coolant leaks. Shut down and allow to cool, then recheck oil level and coolant level, adding as necessary.

Reassembly

1. Install all components in reverse order of removal, ensuring proper torque values for all fasteners
2. Use new gaskets and seals throughout - do not reuse main bearing cap bolts if they are torque-to-yield design
3. Prime oil system before starting by cranking with ignition disabled
4. Verify all electrical connections are secure and properly routed
5. Bleed cooling system completely to remove air pockets after filling

Verification

• Oil pressure should register within 2-3 seconds of startup and maintain 25+ PSI at hot idle, 40-60 PSI at 2000 RPM
• No oil leaks from oil pan, main seal, or any gasket surfaces after warmup and cool-down cycle
• Engine runs smoothly with no unusual noises, knocking, or vibration
• Coolant temperature remains in normal range (190-220°F) during operation
• Crankshaft endplay was verified at 0.004-0.012 inches during assembly
• All bearing clearances were within 0.001-0.003 inches as verified by Plastigage
• After 500 mile break-in, change oil and filter and inspect for metal debris in filter media

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