When you fit these new bevel gears, be sure to:
1. Replace both bevel gears on the TT (front and back), and also replace the counter shaft and tail rotor output shaft.
2. Please respect the placement of the TT bevel gears. The front and back TT bevel gears are not the same. The rear TT bevel gear can be identified by a series of protrusions around the face which mates against the bearing.
3. Please lubricate the gears with a silicone or lithium based grease.