Main Bearings

Complete replacement of main bearings requires engine removal, disassembly, crankshaft inspection, and installation of new bearings with precise torque specifications.

Warnings

Tools required

Parts

• Main bearing set (standard or appropriate undersize) × 1 — Use OEM specification
• Main bearing thrust washers × 1 — Use OEM specification
• Engine oil and filter × 1 — Use OEM specification
• Lower crankcase gasket × 1 — Use OEM specification
• Oil pan gasket × 1 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• New main cap bolts (TTY) × 10 — Use OEM specification
• RTV silicone sealant (Honda Bond HT) × 1 — 08718-0004
• Engine coolant × 1 — Honda Type 2 Blue

Fluids

• Honda Genuine 0W-20 — 4 qt
• Honda Type 2 Coolant (Blue) — 6 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable and wait 3 minutes for SRS system discharge
3. Drain engine oil completely and remove oil filter
4. Drain cooling system completely at radiator drain plug and lower radiator hose
5. Remove engine cover and hood (mark hinge positions for reinstallation)
6. Relieve fuel system pressure by removing fuel pump fuse and cranking engine until it stalls
7. Disconnect fuel lines, vacuum lines, and all electrical connectors from engine (label all connections)
8. Remove air intake system, battery, and battery tray
9. Disconnect radiator hoses and remove radiator with cooling fans
10. Remove accessory drive belt, alternator, A/C compressor (leave hoses attached and secure aside), and power steering pump (no fluid system)
11. Disconnect exhaust system at manifold/turbocharger connection
12. Support transmission with jack and remove engine mount bolts
13. Attach engine hoist with load leveler to engine lifting points

Procedure

1. 1

   Remove engine from vehicle
   Perform final check that all hoses, wires, and connections are disconnected. Carefully lift engine while watching clearances around firewall, brake master cylinder, and A/C lines. Tilt engine as needed using load leveler. Once clear of engine bay, lower onto engine stand and secure with appropriate mounting bolts.
   Torque spec

   Mounting Bolts45 Nm (33 lb-ft)
2. 2

   Remove external components and timing system
   With engine on stand, remove valve cover, timing chain cover, timing chain tensioner, timing chain guides, timing chain, and crankshaft sprocket. Remove oil pan and oil pickup tube. Keep all components organized for inspection and potential reuse. Remove turbocharger and exhaust manifold assembly.
   Torque spec

   Cover Bolts15 Nm (11 lb-ft)
3. 3

   Remove cylinder head
   Remove cylinder head bolts in reverse of tightening sequence (from outer bolts toward center in multiple passes). Lift cylinder head off block carefully. This provides access to pistons and allows complete crankshaft removal. Inspect head gasket surface for warping or damage.
   ⚠Cylinder head is heavy and awkward. Use assistance or lifting device to prevent dropping and damaging surfaces.
4. 4

   Mark and remove connecting rod caps
   Mark each connecting rod cap with its cylinder number and orientation using permanent marker or stamps. Remove connecting rod cap bolts and caps. Push pistons up into bores to clear crankshaft journals. Cover rod bolts with rubber hose to prevent scratching crankshaft journals during removal.
   ℹ️Connecting rod and cap pairs are matched sets and must be reinstalled in original positions and orientations.
5. 5

   Remove main bearing caps and crankshaft
   Mark all main bearing caps with position numbers and directional arrows indicating front of engine. Remove main cap bolts in sequence from outer caps toward center. Carefully remove each main bearing cap, keeping upper and lower bearing shells with their respective caps. Using crankshaft support fixture or careful lifting, remove crankshaft from block. Remove upper bearing shells from block, marking position of each.
   ⚠Crankshaft weighs approximately 40 lbs. Use proper lifting technique and support to avoid injury or damage to journals.
6. 6

   Inspect and measure crankshaft journals
   Clean all crankshaft journals thoroughly with brake cleaner and lint-free towels. Using micrometer, measure each main journal diameter at multiple points to check for out-of-round (max 0.0002 inch) and taper (max 0.0002 inch). Inspect journals for scoring, heat discoloration, or damage. Standard main journal diameter is 52.000-52.013 mm. If journals are damaged or out of specification, crankshaft must be ground to next undersize or replaced.
   ⚠Do not proceed with bearing installation if crankshaft journals are damaged or out of specification. This will result in immediate bearing failure.
7. 7

   Inspect and measure main bearing bores
   Clean all main bearing saddles in block and bearing caps with brake cleaner. Using dial bore gauge, measure each main bearing bore diameter with caps installed and torqued to specification (without bearings installed). Check for out-of-round and proper sizing. Bearing bores must be within 0.0008 inch of specification.
   ℹ️Use new main cap bolts for this measurement step as they will be torqued and angle-tightened. These bolts cannot be reused after final assembly.
   Torque spec

   Main Cap Bolts75 Nm (55 lb-ft) + 56°
8. 8

   Install new main bearings and check clearance with Plastigage
   Install new upper bearing shells into block saddles and new lower bearing shells into bearing caps, ensuring oil holes align correctly and tang locks into notch. Clean journals again. Place Plastigage strip across each main journal parallel to crankshaft centerline. Carefully install crankshaft. Install bearing caps in correct positions with arrows pointing toward front of engine. Install new main cap bolts and torque to specification plus angle. Do not rotate crankshaft.
   ⚠Do not rotate crankshaft with Plastigage installed. This will give false readings and damage the measuring material.
   Torque spec

   Main Cap Bolts75 Nm (55 lb-ft) + 56°
9. 9

   Measure bearing clearances and verify specifications
   Remove main cap bolts and carefully remove bearing caps without rotating crankshaft. Using Plastigage scale, measure width of flattened Plastigage on each journal. Specified main bearing clearance is 0.0007-0.0014 inch (0.018-0.036 mm). If clearance is too tight, verify correct bearing size. If clearance is too loose, next undersize bearings are required. Record all measurements. Remove all Plastigage material completely from journals and bearings.
   ⚠️If bearing clearances are not within specification, do not proceed with assembly. Operating with incorrect clearances will cause rapid bearing failure and engine destruction.
10. 10

    Perform final main bearing installation
    Clean all bearing surfaces and crankshaft journals one final time with lint-free towels and brake cleaner. Verify all oil passages in block and crankshaft are clean and clear. Apply thin coat of clean engine oil to all bearing surfaces and crankshaft journals. Install upper bearing shells in block and lower shells in caps with tabs properly seated. Carefully install crankshaft into block. Install thrust washers in correct position (typically center main bearing). Install main bearing caps in correct positions with directional marks toward front.
    ℹ️Bearings must be absolutely clean and dry before oil application. Any contamination will cause premature failure.
11. 11

    Torque main bearing caps to final specification
    Install new main cap bolts finger tight. Torque all main cap bolts in sequence from center bearing outward to 29 Nm (21 lb-ft). Using angle gauge, tighten each bolt an additional 56 degrees in same sequence. Verify crankshaft rotates freely by hand with no binding. Check crankshaft end play with dial indicator (specification 0.004-0.014 inch). Apply additional light coat of oil to journals.
    ⚠Main cap bolts are torque-to-yield and this is their final installation. Bolts cannot be loosened and retightened.
    Torque spec

    Main Cap Bolts75 Nm (55 lb-ft) + 56°
12. 12

    Reinstall connecting rods and pistons
    Lubricate rod bearings and crankshaft rod journals with clean engine oil. Remove protective hose from rod bolts. Guide each piston back into its original cylinder bore using ring compressor. Align connecting rod with crankshaft journal and install rod cap in original orientation. Torque connecting rod bolts to Honda specification (not provided in this dataset - refer to service manual). Verify each rod has appropriate side clearance on crankshaft journal.
    ℹ️Rod caps must be installed in exact original positions and orientations to maintain proper bearing clearances.
13. 13

    Install lower crankcase and oil pan
    Clean all gasket surfaces on block and lower crankcase thoroughly. Install new lower crankcase gasket and apply small bead of RTV sealant at corners where specified by service manual. Install lower crankcase and torque gasket bolts to specification in sequence from center outward. Clean oil pan mating surface and install new gasket. Install oil pan and torque bolts to specification. Install oil pickup tube with new O-ring.
    Torque spec

    Gasket Bolts19 Nm (14 lb-ft)
14. 14

    Reinstall cylinder head and timing components
    Install new head gasket ensuring proper orientation with UP mark facing cylinder head. Carefully position cylinder head onto block. Install new cylinder head bolts and torque in proper sequence per Honda specification (not provided in this dataset). Install timing chain components including crankshaft sprocket, timing chain, guides, and tensioner per timing marks. Install timing chain cover with new gasket and torque cover bolts to specification. Install valve cover with new gasket.
    Torque spec

    Cover Bolts15 Nm (11 lb-ft)
15. 15

    Complete engine assembly and reinstall in vehicle
    Install all external components including turbocharger, exhaust manifold, sensors, and accessories. Verify all sensors are properly connected and torqued to specification where applicable. Remove engine from stand and carefully lower into engine bay using hoist and load leveler. Align engine mounts and install mounting bolts to specification. Reconnect all electrical connectors, fuel lines, vacuum lines, cooling hoses, and exhaust. Install radiator, battery tray, battery, and air intake system. Install hood using marked positions.
    Torque spec

    Mounting Bolts45 Nm (33 lb-ft)

    Sensor Bolts10 Nm (8 lb-ft)

Reassembly

1. Torque specifications with angle measurements must be followed precisely as main bearing failure will occur with improper torque
2. All main bearing cap bolts are torque-to-yield (TTY) and must be replaced with new bolts - never reuse
3. Main bearing caps must be installed with directional arrows or marks pointing toward front of engine
4. Thrust bearing position controls crankshaft end play and must be installed in correct location (typically center main)
5. Oil all moving parts before initial startup to prevent dry-start damage
6. Double-check that all timing marks align correctly before installing timing cover

Verification

• Fill engine with 4 quarts Honda Genuine 0W-20 oil and install new oil filter
• Fill cooling system with 6 quarts Honda Type 2 Blue coolant and bleed air from system
• Reconnect negative battery cable and perform PCM idle learn procedure
• Start engine and immediately verify oil pressure light extinguishes within 2-3 seconds
• Listen for any abnormal knocking, ticking, or grinding noises during initial startup
• Allow engine to warm to operating temperature while monitoring for leaks at oil pan, timing cover, and lower crankcase
• Check for coolant leaks at all hose connections and head gasket
• Verify no check engine lights or error codes are present
• Perform test drive and monitor oil pressure, engine temperature, and listen for any unusual noises under load
• After 20-30 minutes of operation, shut down engine, allow to cool, and recheck oil level and all fluid levels
• Inspect for any new leaks and verify all fasteners remain tight
• Change engine oil and filter after 500 miles of break-in driving

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