1. Worn CV Boot:
- This is the most common cause. The CV boot is a rubber covering that protects the CV joint from dirt, water, and other contaminants. Over time, the boot can crack, tear, or become brittle, allowing grease to escape.
2. Damaged CV Joint:
- If the CV joint itself is damaged, it can cause grease to leak. This could be due to wear and tear, improper installation, or impact damage.
3. Excess Grease:
- Too much grease in the joint can lead to leakage. This happens when the boot is overfilled during servicing or when the wrong type of grease is used.
4. Improper Installation:
- If the CV joint was improperly installed during a previous repair, it could lead to leakage. This could include a loose boot clamp, a damaged boot, or incorrect positioning of the joint.
5. Manufacturing Defect:
- While less common, it's possible that the CV joint or boot had a manufacturing defect that caused the leakage.
To diagnose the problem, you should:
* Inspect the CV boot for cracks, tears, or other damage.
* Check for signs of grease buildup around the boot or on the wheel.
* Inspect the CV joint for any signs of damage or wear.
* If you suspect the problem is related to excess grease, check the service records to see when the last CV joint service was performed.
Important note: A leaking CV joint needs to be repaired promptly. Ignoring the problem can lead to:
* Damage to the CV joint itself, leading to a costly replacement.
* Wear on the wheel bearings.
* Loss of steering control.
It's best to take your Mazda 626 to a qualified mechanic for diagnosis and repair. They will be able to determine the root cause of the leak and recommend the appropriate solution.
