Suit GU TD42T & TD42TI Motors (Does not suit GQ or GU N/A motors)
This is gear that is located behind the harmonic balancer & damper on the front of the crank.
This gear sometimes needs to be replaced when the crank snaps or the harmonic balancer falls off etc.
We also sell a Harmonic Balancer, damper, keys, seal, nut and all those other kinds of bits available in our online store.