The four have violated team rules, according to an official release.
Reynolds was the most productive of the four last year, ranking third on the team with 41 receptions for 715 yards and five touchdowns.
He led the team with his 17.4 yards per reception.
Franks caught 22 passes for 196 yards, and Jackson finished with 12 receptions for 165 yards.
Hayes was the least productive of the three, participating in eight games as a member of the special teams unit and recording three tackles.
Jackson announced the other day on his Twitter that he was leaving OU for Texas A&M: "Embracing my last week as a Sooner; as I've chose to transfer and further my education and football career at Texas A&M."
But facts surfaced that contact had not been made by either party to make that happen before these four were suspended from the team.