97 starter issue

97 XJ 4.0L auto 4x4

Starter begins to engage the flywheel and turn but disengages the flywheel but continues to free spin.

Is this directly an issue with the starter motor or the solenoid?

I will also add that I have suspected that my battery cables are just old and worn out and it could be time to replace and upgrade to bigger gauge cables.

Fix cable connections first.

While your doing the cables, check the two main bolts holding the starter on for tightness.