Ford Motor Company

My motor had been making a ticking noise for a few months. Changing the oil in it would make the noise stop and it wouldn't start back until the oil needed changed again. Which was every 3000 miles. Well yesterday the motor started making a worse noise. Like the bearing on the crankshaft where trying to come over on each other. I called the dealership and told them what was going on and they said I would need to get a new motor for it. My husband is a mechanic so he was going to rebuild it himself. Only when we started looking up the parts to rebuild it we found out that you can't order the crankshaft from ford seperatly. The only way to get it is to order a remanufacturer motor. How is this even possible that Ford doesn't sell the parts to fix the vehicle~