Rear DT wheel slip/slide intermittent. ~~~~~ Checked on Tims and found #3648 having FC 327 BCU speed probe 4 fault. Measured #3648 no 4 probe-2ohms fluctuating. Replaced tacho, measured impedance-934ohm ok. Conducted limited movement and depot shunting ok. #3648-#4 tachogen-Old: 1504472. New: 9928022. Not:2272981 Raised. Done by Sanip/Omar. 30/04/21.