Before purchasing:
* Check Service History: Obtain the service history of the vehicle the transmission was used in to ensure it has been properly maintained.
* Request a diagnostic report: If possible, ask the seller to provide a diagnostic report to identify any potential error codes or problems.
Upon personal inspection:
* Check the automatic transmission oil: Check the oil for a burning smell, metal shavings, or discoloration. Pure red or rose oil is a sign of good condition.
* Inspect the automatic transmission pan: The automatic transmission pan should be clean without any leaks or damage.
* Check the output shaft: Turn the output shaft by hand. It should rotate smoothly without any sign of play or noise.
* Check the condition of the connectors: Make sure that all electrical connectors of the automatic transmission are clean and free of corrosion.
*Test Drive (If Possible): If possible, test drive with the transmission installed. Check for smooth gear shifting and no vibration or noise.
When installing:
*Use New Oil and Filter: Be sure to use new ATF (automatic transmission fluid) oil and a new filter when installing a new transmission.
* Reset transmission adaptations: Some car models require transmission adaptations to be reset after replacing it.
* Re-test: After installation, re-test to ensure there are no problems.
Other tips:
* Buy a contract gearbox from a reliable supplier.
*Get a written warranty on your transmission.
* Consider having the transmission installed by a qualified mechanic.