My jacks don't creak (yet), but there was a fair amount of movement (wobble) in the chassis whenever someone was walking around. I quit using the stabilizer jacks in the back of the fifth wheel, replacing there function with heavy duty automobile jack stands - I still had a fair amount of wobble. My neighbor said that he found some light duty screw jacks and installed them midway along the chassis frame and they worked great for reducing the wobble. I found these screw jacks at a RV supply store (rated for 3 tons, for stabilization use only). They came 2 to the box for about $26.00. After installing them, there is hardly any wobble at all when someone is moving around the interior and much less movement when someone is using the entrance stairs. So, if you are up the creak, you might want to try this...
Tom