Engine not starting?

Yes, if the starter is cracked it will cause it not to work. I would use a breaker bar on the front of the engine to make sure it turns by hand, then replace the starter motor. It could have just fatigued and let go. Here is how to change it out in case you need it. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.