What was found
R ENG OIL PRESSURE WARNING ON CLIMB OUT FOLLOWED QRH / REMOVED RH ATS IAW CRJ 900 AMM 80-11-01-000-801-A01 AND FOUND O-RING ON SPLINED SHAFT TO BE INSTALLED INCORRECTLY, FOUND OIL ON UNDERSWIDE OF THE HOUSING SEEPING OUT FROM THE GEAR BOX. REMOVED AND REINSTALLED RH ATS IAW CRJ 900 AMM 80-11-01-400-801-A01-PSA REV E. SERVICED RH ATS IAW CRJ 900 AMM 80-11-01-610-802-A01-PSA. OPS CHECK GOOD. NO FURTHER DEFECTS NOTED.