Balancer Chain, Sprocket and Tensioner Installation

Special Tools 

EN-50837  Timing Chain Tensioner Retraction Tool

For equivalent regional tools, refer to Special Tools .

1. Assemble the crankshaft sprocket, balancer shaft driven sprocket and balancer chain. Ensure the timing link (1) lines up with the timing mark (2) on the crankshaft sprocket. Ensure that both timing teeth (3) on the balancer shaft driven sprocket line up with the timing links (4).
   Fig 1: Timing Link Lines & Timing Mark

   Courtesy of GENERAL MOTORS COMPANY
   NOTE: Proper setup is critical to ensure correct timing when installing the sprockets and chain simultaneously onto the shafts. The timing links are heat treated blued steel.
2. Install the sprockets and chain (2) as an assembly to the crankshaft and balancer shaft assembly.
   Fig 2: Balancer Shaft Driven Sprocket And Balancer Chain

   Courtesy of GENERAL MOTORS COMPANY
   NOTE: The crankshaft keyway should be in the 12 O'clock position.
3. Install the crankshaft key (1).
4. Ensure the timing link (1) is aligned with the crankshaft sprocket timing mark (2).
   Fig 3: Timing Link Lines & Timing Mark

   Courtesy of GENERAL MOTORS COMPANY
5. Ensure the adjacent timing links (4) are aligned with both of the timing marks (3) on the balancer shaft driven sprocket.
6. Install the NEW balancer shaft driven sprocket bolt (1).
   Fig 4: Balancer Shaft Driven Sprocket Bolt

   Courtesy of GENERAL MOTORS COMPANY
   CAUTION: This vehicle is equipped with torque-to-yield or single use fasteners. Install a NEW torque-to-yield or single use fastener when installing this component. Failure to replace the torque-to-yield or single use fastener could cause damage to the vehicle or component.
7. Use an open end wrench over flat on balance shaft while tightening the balancer shaft sprocket bolt to specification. Tighten the balancer shaft driven sprocket bolt to 40 N.m (30 lb ft) plus 50 degrees.
   CAUTION: Refer to Fastener Caution .
8. Install the balancer chain guide (2).
   Fig 5: Balancer Chain Guide Bolt

   Courtesy of GENERAL MOTORS COMPANY
   NOTE: Ensure the guide is installed in the correct orientation. The long end must point toward the crankshaft and the flat edge must be adjacent to the balance chain.
9. Install the balancer chain guide bolts (1). Tighten the bolts to 10 N.m (89 lb in).
10. Install the balancer chain tensioner (2).
    Fig 6: Balancer Chain Tensioner Bolt

    Courtesy of GENERAL MOTORS COMPANY
11. Install the balancer chain tensioner bolts (1). Tighten the bolts to 10 N.m (89 lb in).
12. Remove EN-50837  retention tool to restore the tension to the balancer chain.