Engine Flywheel Installation

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Important:

The flywheel does not use a locating pin for alignment, and will not initially seat against the crankshaft flange or spacer, if applicable, but will be pulled onto the crankshaft by the engine flywheel bolts. This procedure requires a three stage tightening process.
Certain applications, the 4.8L manual transmission and all 6.0L, require a spacer and longer bolts for proper flywheel position.

Install the spacer, if applicable, onto the rear of the crankshaft.
A longer flywheel bolt must be used on applications using a flywheel spacer.

Fig 1: Installing Spacer Onto Rear Of Crankshaft
Courtesy of GENERAL MOTORS CORP.
Install the automatic transmission engine flywheel to the crankshaft, if applicable.
Important: A longer flywheel bolt must be used on applications using a flywheel spacer.
Apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the threads of the flywheel bolts.

Fig 2: Installing Engine Flywheel
Courtesy of GENERAL MOTORS CORP.

CAUTION: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
Install the engine flywheel bolts.
Tighten
1. Tighten the engine flywheel bolts first pass in sequence to 20 N.m (15 lb ft).
2. Tighten the engine flywheel bolts second pass in sequence to 50 N.m (37 lb ft).
3. Tighten the engine flywheel bolts final pass in sequence to 100 N.m (74 lb ft).
  
  Fig 3: Tightening Engine Flywheel Bolts In Sequence
  Courtesy of GENERAL MOTORS CORP.