What was found
DURING CLIMB OUT, AT 16000 FT, RECEIVED A ALT DISAGREE MESSAGE ON SCREEN. CONFIRMED MORE THAN 200 FT (230-300FT). LUBRICATED AT FL 280 AFTER READING QRH. CANX ITSELF AT 120. PERFORMED FIM 34-12-T804 , PERFORMED ADC CHECK & ALTIMETER & AOA CHECK, NO FAULTS NOTED. REPLACED RIGHT ADC AS A PRECAUTION. OK TO CONTINUE. ACCOMPLISHED TEST 30. TEST PASSED PER 22-00-02. NO FAULT NOTED.