They say Freeh's report, which was prepared for the university, and the NCAA's ensuing $60 million in fines unfairly punish the entire university community.
Twenty-nine past chairs of the faculty senate signed a statement posted online Tuesday that condemned the report and sanctions.
Freeh's report concluded that top university officials concealed information about sexual abuse allegations against Sandusky to avoid bad publicity. It has come under fire from ousted school president Graham Spanier, the family of late football coach Joe Paterno and others.
Freeh defended his work Tuesday in an interview with The Associated Press. He insisted his report wasn't compromised by his inability to interview key witnesses.
Sandusky was convicted in June of abusing 10 boys.