TIMS showed intermittent obstacle detected at Rear DT car 'B2' door. Staff (DBG) checked and confirm ed, train door closed with a jerking motion but door was pro ven closed. Staff (RFP) sent video to CC duty phone. ~~~~~ TIMS showed intermittent obstacle detected at Rear DT car (3612) 'B2' door. Staff (DBG) checked and confirmed, train door closed with a jerking motion but door was proven closed. Staff (RFP) sent video to CC duty phone. CE: 3612-B2 doors  opening and closing jerkiness. Bottom rail no foreign    objects. Able to closed doors.  Checked and found #3612 B2 and B4 LHS door roller damaged. Changed out door rollers. Mating strip ok, push pull force satis, DSS ok, DLS red line aligned, door cyclic and door static checks ok. Done by: Jack/Sanip/Koh 45226