G-73 provides an absolute replacement matrix. Immediate replacement is mandatory if:

for the maintenance of the running gear and tapered roller bearings. Indian Railway

Draft revised particular specification No. G-73(1).pdf - RDSO

: Step-by-step instructions for mounting bearings, operating shafts, and door levers. Maintenance Schedules : Specific checks required during (Routine Overhaul) and (Periodic Overhaul). Troubleshooting