Timing Belt Replacement AJM Engine

Hello everyone,

The timing belt in the AJM engine needs to be replaced every 60,000 km. However, for a later model year, wasn't the interval increased to 90,000 km?
Was exactly was replaced: just a different timing belt, or also timing belt pulleys, tensioner, etc.? Can the replacement interval be extended by replacing these parts?

Best regards,
Stefan
1.9 TDI PD AJM 85kW