Does grandpa have a criminal record that affects his grandson?

Legal analysis: Yes. Criminal records will affect future generations' participation in civil service examination, recruitment and political examination in banks, state-owned enterprises, institutions, military schools and police schools. You can't pass the political examination, you can't be admitted to civil servants, soldiers, banks, state-owned enterprises and institutions, and you can be admitted to military schools and police academies.

Legal basis: Article 8 of the Provisions on Political Review of Conscription in People's Republic of China (PRC), citizens under any of the following circumstances shall not be enlisted for active service (IX). Having been subjected to criminal punishment, expelled from the Party, dismissed from public office, or having serious illegal problems that have not yet been ascertained, and harboring or taking revenge.