Final answer:
A press-fit harmonic balancer should be removed using a three-jaw gear puller, and a damaged keyway on a harmonic balancer should be replaced.
Step-by-step explanation:
A press-fit harmonic balancer should indeed be removed using a three-jaw gear puller. This tool is designed to safely grip the balancer and pull it off the crankshaft. It applies equal force to all three sides of the balancer, ensuring that it is pulled off evenly.
If a harmonic balancer has a damaged keyway, it should be replaced. The keyway is an important part of the balancer's connection to the crankshaft. A damaged keyway can cause the balancer to shift or rotate incorrectly, leading to engine damage.
Therefore, both statements A and B are correct. A press-fit harmonic balancer should be removed using a three-jaw gear puller, and a harmonic balancer with a damaged keyway should be replaced.