I get the chatter from mine when they are fully extended, or completly closed. Mine only does this for a second, kinda lets me know when I have gone far enough. Yours making it when you said may be an alignment problem, or something rubbing.
2010 Jayco Eagle Super Lite 31.5 FBHS
08 Chevy 2500HD LTZ Duramax /CC/SB/4x4