Why does a Nissan Stanza Auto gear shift move normally but car does not go into any gears you can see the shaft slide into the transmission but car always acts as if it were in park or neutral?

Why does a Nissan Stanza Auto gear shift move normally but car does not go into any gears you can see the shaft slide into the transmission but car always acts as if it were in park or neutral?
If I remeber corectly the shifter shaft in the Transmision rotates,not go in and out.

But regardless of that this transmision has a serious internalproblem.

It could be as easy as the linkage inside the transmision hasfallen apart or the whole inside of the Transmision is ruined.

BUT FIRST: Check the automatic transmision fluidlevel!