Callback action from 2008 – now have had or is it still possible?

Hello 2008 different models were called back by GM due to differential sealing problems. my had probably not been brought there by the previous owner – since yesterday the diff. ;( there is possibly still a possibility to do this via cadillac? is also a US model. a used car warranty I have for luck also – only the only demanded first of course the manufacturers related recalls to try. The STS has nnun 47000 km down and is built in 2005 – the recall w r 2008. has a possibly already had experience with a late recall action? thank you