* Worn gears: This is the most common cause. Over time, the gears inside the transmission wear down, producing metal particles that migrate to the pan. This is often accelerated by low transmission fluid levels, harsh driving, or age.
* Worn bearings: The bearings that support the rotating parts of the transmission can also wear out, generating metal debris. This often leads to noisy operation before significant shaving accumulation.
* Failed clutches or bands: The clutches and bands within the automatic transmission are responsible for engaging and disengaging gears. Failure of these components can release significant metal particles.
* Damaged synchronizers (manual transmission): If the Aerostar has a manual transmission (less likely), damaged synchronizers can cause metal shavings.
* Contaminated fluid: While less likely to produce *large* shavings, extremely dirty transmission fluid can contribute to abrasive wear, leading to smaller particles.
In short: The metal shavings are a symptom of internal damage within the transmission. It's not something that can be ignored. The transmission likely needs significant repair or replacement. The severity depends on the amount of shavings and other symptoms (e.g., slipping, harsh shifting, noise). A professional transmission mechanic should inspect the transmission to determine the exact cause and necessary repairs.
