Helping a friend with his 91 Olds Bravada that has a "ting" noise

There is a ting noise that seems to be coming from the bell housing area. There is no pattern to the noise. When the engine is reved, the noise is more freqent and pronounced. Upon removing the cover it appears that the starter might not be disenganging enough. You really can’t hear the noise from the top side. I thought I had found the problem until the AC was turned on. While ideling and AC on, the noise becomes louder and more freqent.

might be a broken flywheel.