Speed bumps and van squeaks

Every time I go over a speed bump, I hear a squeak sound coming from under the van.

What could this be? I purchased extended warranty and what are my chances of whatever it is being covered by warranty?

I think you are going to have to be a lot more specific about that noise. First, what year and how many miles? Next, where is the sound coming from, the front or the back?
Do you have the automatic load leveling system on your van? Does it have a trailer hitch installed?

Can you cause the sound by rocking the van when its not moving?
Some folks would be happy to have only a 'squeak' sound when they hit bumps. Its the 'clunk' sounds you want to worry about.