Starter issue

The starter engages perfectly when the car is cold. However, when the car warms up, the bendix will not always engage. The starter will "free spin"and not turn the motor over. Often times, but not always, rocking the car with it in gear and then trying to start the car will work. The starter does not experience any slow down or lack of power when warm, it just doesn't always engage correctly. Time to replace the starter? Other suggestions?

Problem resolved. I climbed underneath to make sure the starter bolts were tight. I found the top bolt was missing entirely....don't you love buying a used vehicle...