Gear Replacement On HXT900 Servos
#1

Get out your box of crash damaged HXT900 servos that have jammed, stripped, or broken gears and fix them. HobbyCity sells replacement gear sets for $0.99, and it only takes 5 minutes to replace them. Here's how to do it:
Step 1: Remove the servo arm. Use a small Phillips screwdriver to remove the 4 screws that attach the cap to the servo body and remove the cap.
Step 2: Remove the idler spindle and associated gears. Lay the gears out in the order removed so that the replacement gears can be exactly matched to those removed.
Step 3: Grasp the upper drive gear that the servo arm attaches to and pull it straight off. This will take a good tug. Remove the lower gear as well.
Step 4: Lubricate the replacement gears with a light coating of petroleum jelly. Some may prefer KY.
Now replace the spindle and stack the gears in the appropriate order.

Step 5: The drive gear to which the servo arm attaches must be pressed on. Align the cogs as best you can. Invert the servo and press the gear straight on against the workbench.
Step 6: Replace the cap on the servo body. Replace the 4 screws that hold them together. Replace the servo arm. Test the rebuilt servo to be sure that it works smoothly and you're done.

Last edited by Marc; 08-18-2009 at 07:11 AM.