Compatible transaxle for 2006 Pontiac Grand Prix

Just get a new front axle, there cheap enough.

Unless of course its a transaxle you require in which case you will need to make sure you get the right one. If you're buying from a reputable auto wrecker they will be able to make sure you get the right one. If a transmission shop is involved they will also make sure you get the right one. If you're a do it yourselfer wikipedia is often a good source for model numbers and years of compatability.