Husbands hands shake when he tries to do fine motor tasks

Hi, my husband is 57 years old he was a mechanic his who life. He has been retired from being a mechanic for 3 years. In the recent year his hands are starting to shake when he is trying to do something fine motor like screwing a screw in or putting glue on a small part. He seems to have no other symptoms. His hands don't shake at regular times. Who could it be? I assume he should see a neurologist.