Overfilling the oil fixes a big problem

Surely this '99 Expedition has an auto transmission. How does pushing or coasting the thing help start it??
Mountainbike " What’s probably happening is that by rolling the car and then popping the clutch the tranny is turning the flywheel to get the missing tooth area past the starter motor and the starter can then grab normally".

If the thing HAS a clutch, rolling the car, turning on the ignition, putting it in gear, and popping the clutch would start the engine, with or without teeth missing.

I suggest you check the idler pulley bearing to see if it is worn out. It is the device that puts tension on the fan belts. When the bearings get dry they can squeal. The pulley will also wobble if the bearing is worn.