Depress the button on the seat belt buckle. If the belt does not fully retract, pull it out and check for kinks or twists. Then make sure it remains untwisted as it retracts.

NOTE
If a belt does not fully retract, inspect it for kinks and twists. If it is still not retracting properly, have it inspected at an Authorized Mazda Dealer.
Fastening the Seat Belt
Front Shoulder Belt AdjusterMazda 6 Owners Manual: Oil seal (differential) replacement
1. On level ground, jack up the vehicle and support it evenly on safety
stands.
2. Drain the oil from the transaxle.
3. Remove the front wheels and splash shields.
4. Separate the drive shaft and joint shaft from the transaxle. (See DRIVE
SHAFT REMOVAL/INSTALLATION.) (See JOINT SHAFT REMOVAL/ ...
Mazda 6 Owners Manual: Expansion valve removal/installation
1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. (See RECOVERY.) (See CHARGING.)
Caution
If moisture or foreign material enters the refrigeration cycle,
cooling ability will be lowered and abnormal noise will occur. Always
immediately plug open fitt ...