The spacers come with the RR and the RTRs. They are small, black, rectangle, plastic spacers. They go under the servo ears. So they'd be between the servo and the radio tray, lifting the servos up. check both servos when you pull the radio tray. It's too easy to do, so don't skip it. I'm not sure if the manuals mention servo spacing or not, but I don't remember seeing it. At any rate, the trucks are supposed to come with the spacers in a small back with a few other little items.