Engine Flywheel Installation

Important: 

• For manual transmission applications, note the position and direction of the engine flywheel before removal. The flywheel does not use a locating pin for alignment. Mark or scribe the end of the crankshaft and the flywheel before component removal. The existing manual transmission engine flywheel must be installed to the original position and direction. The engine flywheel will not initially seat against the crankshaft flange, but will be pulled onto the crankshaft by the engine flywheel bolts. This procedure requires a three stage tightening process.
• DO NOT remove the propshaft hub or flexplate from the automatic transmission engine flywheel. The flywheel, prop shaft hub, and flex plate are balanced as an assembly. If service is required, the entire flywheel assembly should be replaced.

1. Install the manual transmission engine flywheel to the crankshaft. Refer to ENGINE BALANCING  .
   Fig 1: Installing Manual Transmission Engine Flywheel To Crankshaft

   Courtesy of GENERAL MOTORS CORP.
2. Install the automatic transmission engine flywheel to the crankshaft.
   Fig 2: Installing Automatic Transmission Engine Flywheel To Crankshaft

   Courtesy of GENERAL MOTORS CORP.
3. Apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the threads of the flywheel bolts.
   NOTE: Refer to FASTENER NOTICE .
4. Install the engine flywheel bolts.
   Fig 3: Identifying Engine Flywheel Bolts Tightening Sequence

   Courtesy of GENERAL MOTORS CORP.

   Tighten 

   1. 4.1. Tighten the engine flywheel bolts first pass in sequence to 20 N.m (15 lb ft).
   2. 4.2. Tighten the engine flywheel bolts second pass in sequence to 50 N.m (37 lb ft).
   3. 4.3. Tighten the engine flywheel bolts final pass in sequence to 100 N.m (74 lb ft).