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Fix Your RC Car's Servo Yourself

Whether your RC Car is powered by battery (electric) or from nitro, your car will have at least one servo that will control the actions of your car. Servos need maintenance on occasion just as your RC car does. One of the most common problems you will encounter with a servo is a stripped gear set or one that has simply worn out. It's easy to tell when that happens, instead of following a radio command, the servo will not turn or you will hear a "crackling" sound when you give it radio input. You will need to change the gear set and fortunately this is a problem most people can fix themselves.

You will need a small jeweler's screwdriver or a Torx driver, depending on the type of servo your RC car has. Replacement gear set. Silicone grease. Cotton swabs and a small brush. Motor spray is handy and so is bearing oil but they are not mandatory for this procedure. It is helpful to spread out a white cloth to work on, so if you drop a small part, it can be found quickly.

First, remove the servo from your RC car and take off the servo horn or servo saver that you will see attached to the output shaft. Clean the outside of the case with a brush and knock off all the dirt and debris. Be especially diligent around the area where the shaft exits the servo case. This is so that no dirt or debris drops into the servo case when you open it.

There should be four screws that hold the case down. Simply unscrew them and then gently pull the case bottom and top apart. Press down on the servo-output shaft while you pull up on the case tabs to allow the gear set to remain intact, otherwise they will fall out. You will see the tiny shafts on which the gears themselves spin, carefully remove it and set it aside. Lay the gears out in exactly the order you take them off so when you are ready to put them back in you can simply pick them up in order.

Use a cotton swab to clean out all the grease from the interior of the case and the area around the gears. When gears "chip a tooth" the plastic will normally get imbedded in that grease, be sure to clean it all out. If you wish at this point you can add a drop or two of bearing oil to your bearings (if the RC car has them) and clean them before doing so. Lightly oil all moving parts such as the near gears, metal gears and the shaft. Use just a drop or two so the oil won't run out when you put the case back together.

Install your new gear set. The top gear normally has a notch to limit the travel of that gear within the case. Pay close attention to proper gear arrangement as you reassemble. If your servo has a rubber seal, wipe it clean, place it in the seam between the case parts, and then reinstall the screws and you're done!
 posted by  Raceway RC Cars and Trucks