Did i lose my Stratocasters whammy bar/ tremolo spring?

I bought a new standard strat and i have been playing it for a few weeks without the whammy bar screwed on. I finally tried to put it on the other day and it just screwed and screwed with out much resistance until it was so low that it wouldnt screw anymore because it was hitting the volume knob. At this point i got out the owners manuel and i saw that it said that when not using the whammy bar you should put a piece of tape over the hole where the whammy bar goes into the guitar because there was a little spring that could fall out and get lost. I tried to look in the hole but I dont think I see any spring. Did I lose this little spring or am I just doing something wrong? Also if I do need another spring where can I get one? Thanks