Staff Feedback to OCC: Train 229 external display was showing wrong number. To add on, in rear DT, t here was an unusual knocking and creaking soung from the und ercarriage when train was in motion. Staff(NOV) checked and ~~~~~ 3525 checked visually & found no abnormalities. During depot shunting, found abnormal noise was present. Suspect #3525 semi-permanent coupler draft gear faulty. Notif 2220838 raised to RSW for rectification. Unable to check on wrong train number. Both cab train number display units are in working condition.  Sarma. 18/11/2020. Notif 2220838. Name:Kana(Team 7/RSD/UPD) Date of Occurrence:18/11/2020 Last Service Date:Nil EMU / Equipment / Location:525/526/Semi Permanent Coupler/#3525                             End 2 Equipment Serial No. (if any):Nil Description of fault /cause:Rubber cushion drawgear having                                   cracking noise during movement.