I have a 2.2L automatic cobalt sedan and the axle replacement isn’t going as planned. The axle shaft that connects the passenger axle to the transmission is not coming off of the old one. Is there any place that sales the axle shaft separate from the axle itself.

 

Welcome from Florida. They aren't that expensive so it's better to get a new one or a rebuilt one. You can also take yours into a axle shop and have your rebuilt.