The impacts were a snap-on battery-powered and pneumatic, powered by a 100 lb/ 6 CFM compressor.
When I used the starter method, I had the breaker bar resting on top of the frame on the driver side. When I started the motor, I heard the starter rev, then the sound of the broken breaker bar hitting the ground.
I have the tool itself covered, but it's the inner ring of the harmonic balance itself that's now spinning loose. It's the part that has the two holes that receive the tool you illustrated.