What was found
STEEERING INOP CAUTION MSG IN FLT. RESET SW FROM ARMED TO OFF TO ARMED PER QRH MSG REMAINED. GEAR WAS UP. EXTENDED GEAR ANDED WITHOUT INCIDENT ATTEMPTED SW RESET AGAIN NO FIX. TAXIED TO GATE WITH BRAKES AND THROTTLES. CW FIM FAULT RESET WITH CB RESET NO FIX. STEERR INOP MSG REAPEARS AND THERE IS NO AUDIBLE CLUNK WITH #3 HYD PRESURED ***AIRCRAFT REMOVED FROM SERVICE*** INSP AND FOUND RH RVDT OUT OF RIG, R&R RH RVDT IAW AMM 32-50 OPS CHECK GOOD.