* Worn output shaft bearings: These bearings support the output shaft. Wear and tear, or lack of lubrication, will cause excessive play. This is a very common cause.
* Damaged output shaft: The shaft itself might be bent, fractured, or severely worn, preventing a secure fit within the bearings and the transmission case.
* Worn or damaged output shaft bushing: Some transmissions use bushings instead of, or in addition to, bearings. These can wear out, leading to looseness.
* Improper installation: If the transmission was recently rebuilt or replaced, incorrect assembly could leave the output shaft loose. This includes improper bearing seating or incorrect torque on fasteners.
* Case damage: A cracked or damaged transmission case could affect the alignment or support of the output shaft, leading to looseness. This is less likely but possible.
* Deteriorated seals: While not directly causing looseness, severely deteriorated seals can allow fluid leakage, leading to insufficient lubrication and accelerated wear of bearings, exacerbating the problem.
It's crucial to understand that a loose output shaft indicates significant internal transmission problems. Trying to fix this yourself without proper mechanical knowledge and tools is extremely risky and could lead to further damage or injury. You should take your Thunderbird to a qualified transmission specialist or mechanic for diagnosis and repair. Attempting to drive with a loose output shaft will likely cause further damage and potential catastrophic failure.
