Sounds like your servo savers too tight loosen the screw that holds the arm on the servo a teeny bit.
Or you might want to try out a metal geared servo. One of the lower cost MG servos I found was the hitec 645MG there sold on ebay for $28 shipped by some dude (I bought 3 off him) I got them in my Jammin RC's and haven't stripped one yet from some pretty bad hits.