Hi There, here you go:
53462 : TA04 Alu Diff Pulley
53489 : TA04 Alu Center One Way Pulley (15T)
53474 : TA04 Alu Center Pulley (15T)
53510 : TA04 Hard Center Pulley SHaft
Use the last 3 part in combination and the first part as a replacement for the plastic diff pulley..... problem solved. Try Towerhobbies for purchase (for example).
If you need to see pictures etc go to www.tamiya.nl
click tamiya logo go to Spare parts & hopups and see.... a list of the tuningstuff for the different chassis.