GM Service Manual Online
For 1990-2009 cars only

First Design 2004 - 2005

Important: This design, called "First Design" was used:

   • 2004: All Applications
   • 2005: Buick Rendezvous Only


Object Number: 2048145  Size: LF
    • The first design crankshaft sprocket incorporates roller timing drive chain teeth (3) with a molded-rubber cushion ring (4).
    • The first design primary timing drive uses a roller timing drive chain (1).
    • The first design intermediate drive shaft sprockets incorporate roller timing drive chain sprocket teeth (2) for the primary and secondary timing drive chains.

Second Design 2005 - 2006

Important: This design, called "Second Design" was used:

   • 2005: All Applications except Buick Rendezvous
   • 2006: All Applications


Object Number: 2048149  Size: LF
    • The second design crankshaft sprocket (5) incorporates an inverted tooth (IT) timing drive chain without a molded-rubber cushion ring.
    • The second design primary timing drive uses an inverted tooth timing drive chain (1).
    • The second design intermediate drive shaft sprockets incorporate IT timing drive chain sprocket teeth (4) for the primary timing drive chain (1) and roller timing drive chain sprocket teeth (3) for the secondary timing drive chains (2).
    • The second design IT timing drive system can be used in place of the first design roller timing drive system but all of the following primary timing drive components must be changed to the IT design:
       - Primary timing drive chain
       - Crankshaft sprocket
       - Left intermediate drive shaft sprocket
       - Right intermediate drive shaft sprocket