In the cup that your dogbone set's in, look in there.....ok seee there is a little round rubber O ring, That is a O ring.

Plus you can not I repeat can NOT go by the parts book they gave you, I ran into the same thing and what they was calling for was way longer then what I needed, what I would do is go to the redcat forums and tell them what your looking for, and they will get you what you need. http://www.rcuniverse.com/forum/foru...smode_1/tt.htm