Seat Ibiza gearbox clunks

Checked the ATF ? May just be wear and tear on a car of that age .

What does ATF mean in your answer.
Regards Stuart

How do I check the auto gearbox oil level on this car

ATF - auto transmission fluid .It's supposedly a sealed for life unit , but checking aint easy .

" Depending on the type of gearbox there are one or two drain plugs. Remove one and drain the oil. Remove the second one and drain the rest of the oil. Remove the filter (sited on top of the gearbox) and replace with new. Refit one of the drain plugs. Fit a special oil fill tool to the second drain port and fill with oil til it overflows, then stop. Leave the drain port open and connect either a dealers diagnostic system or VCDS to the cars OBD port. Access some measuring blocks and start the engine. Run until the gearbox oil hits specific temperature, during which time excess oil will be discharged through the still open drain port. Once the gearbox oil hits critical temperature, switch off the engine and reconnect the drain plug.

This gives the correct fill level at running temperature and must be done to ensure that the oil is nether under filled or overfilled. Both are bad for the gearbox. "