95 cherokee sport won't start. Have switched starters and had newest one checked, checks okay. When i turn key to start I can hear starter drive gear ping against flywheel. Visual inspection of flywheel reveals no cracks or visual warping (removed inspection cover and starter and manually turned flywheel), reinstalled starter, still just pinged against flywheel, not engageing or spinning motor.

Sounds like its hitting the flywheel, but not engaging the ring gear. try loosening the bolts and position the starter in such a way to move the gear away from the ring gear. it may only be a small amount but enough to get the bendix to engage the ring gear correctly.