Yamaha replacement parts carry a one year warranty, but they do not include labor to diagnose or to replace them.
If the gears were the original ones with the motor, and not replacement parts, then they may be covered by the engine warranty if it is still in effect. Make sure the propshaft is not bent, the skeg shows no signs of bottom hitting or impact damage, and that the prop is in good shape. Damage from underwater impacts are not covered by warranty but may be by your insurance company.
Last edited by seahorse; 08-13-2012 at 11:23 PM.