Smaller Pitch Timing Chain
The 3.6L V6 VVT in the Cadillac CTS has a new timing chain with a smaller pitch (7.7 mm compared to 9.5mm previously) and more links. The chain features an inverted tooth design. The smaller links engage at a lower impact speed, which decreases the noise generated. In conjunction with the new chain, the number of teeth on the sprockets is also increased, increasing the meshing frequency and further reducing noise and vibration.
The new timing chain is a running change that will occur in all of GM Powertain’s V6 VVT engines through the course of the 2007 model year.