I loaded a youtube video showing how electric retracts can be hooked up with a gear door sequencer using 2.4 ghz controls. If you don't need doors that are sequenced to the gear omit that item and it really becomes easy.
Electric retracts plug into the receiver and behave like a servo. Flip the toggle switch on your controls and the gear goes up and down. Some of the RC car transmitter are not setup correctly to control a toggled item like retracts. The transmitters that hang on your hip have toggle switches that will work these items with no problems.
Fred