Revo SX grind

My Revo SX has been making a grinding sound and can feel it when reeling it in.  I took it about and I can see where it is coming from.  One of the small gears that sits in there does not sit tight and moves around causing the two gears to grind somewhat.  Not knowing what they call this gear I can't tell you which one.  But looking at it can't see how it would get "stretched" out.  

Oh were is "The Reel Mechanic?"