GM Service Manual Online
For 1990-2009 cars only

    Object Number: 412520  Size: SH

    Important: If the balance shafts are not properly timed to the engine, the engine may vibrate or make noise.

  1. Install the balance shaft drive chain with the colored links lined up with the marks on the balance shaft drive sprockets and the crankshaft sprocket. There are three colored links on the chain. Two links are of matching colors, and one link is of a unique color. Use the following procedure to line up the links with the sprockets:
  2. Orient the chain so that the colored links are visible.

  3. Place the uniquely colored link (1) so that it lines up with the timing mark on the intake side balance shaft sprocket.
  4. Working clockwise around the chain, place the first matching colored link (2) in line with the timing mark on the crankshaft drive sprocket. (approximately 6 o'clock position on the crank sprocket)
  5. Place the chain (3) on the water pump drive sprocket (alignment is not critical).
  6. Align the last matching colored link (4) with the timing mark on the exhaust side balance shaft drive sprocket.