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SERVO GEAR REPLACEMENT
 for the HSR-8498HB
 

As you can see from this picture (above), the teeth on this gear are nearly gone. This obviously needs to be fixed. I have drawn up a small step-by-step guide for those who have never replaced a servo gear-set before. Looking under the cover, the array can look very intimidating. Don't worry, it's not so bad. You'll be up and running in no time.

Things that will help: A #1phillips screwdriver, a flat-head jewelers screwdriver, a pair of angled needle nose pliers, a good light source, and a clean table.

NOTE:  By viewing this page, you (the viewer) agree to, not in any way hold me (Matt Bauer) accountable for any discrepancies you may have encountered as a result of following this tutorial. Thanks.

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Fist things first:
- Remove the servo from the bracket.
- Remove the servo horn (disk) from the drive gear (the numbered horn that does not freely spin).
- Unscrew the cover, and remove the gear casing by carefully pulling the two apart while pushing down with a free finger on the drive gear. This should come apart with the gears stacked in their original positions, apart from the case cover. If this doesn't work quite the same, you're still okay. Just take the gears out.
- In most cases the two steel axel pins will remain inside the gear-case no matter what. Remove them using the needle-nose pliers.
- As you remove each gear, look to check the extent of the damage. A badly damaged servo (like the one I had) is a good indication that you may have a lot of debris to accompany a stripped gear. Look over the entire interior, and dispose of any gear particles that remain. The slightest crumb may find its way between the teeth of a pair of gears and severely damage them - resulting in having to do this all over again.
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- It is best to just replace all the gears. Just because you didn't notice a flaw, doesn't mean there's not one there. The teeth are tiny, and any imperfection can affect a servo's precision.
-The little white plastic horn (see picture below) connects one of the gears to the potentiometer (pot). In some cases, it may still be inside the gear. If not, remove it from the pot shaft.
-The removal of the bottom-most gear, also requires the removal of the bearing that slightly overlaps it. I have yet to clip my nails, so I was able to pry it off with my fingers. If you don't have the luxury of grotesquely long man-nails, then I suggest using a jewelers flat screwdriver to carefully pry it off.

- Place the new thin flat gear against the teeth of the motor-gear.
- Re-secure the bearing over the pot-housing.
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- Place the next gear assembly on (see picture above).
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- Insert the two steel gear-pins through the gear holes and into the casing. You may have to hunt around a little for the holes, but the pins will fit securely into place once correctly positioned.

- Push the little white pot-horn into the next gear assembly.
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- The last two gear assemblies need to be inserted together. One over the pin, and the other correctly lined up with the pot-shaft (see picture below/left). Notice that the gear that fits over the pot has a two stops on the gear assembly (see picture below/right). Those stops will face outward, away from the rest of the gears. Don't worry, it will only go on one way.
 

-Be sure the white plastic horn is correctly lined up over the pot-shaft, and press it into place.
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- Apply a modest amount of grease onto the teeth of each gear. It doesn't have to be too thorough, the grease will work itself to all the teeth eventually during operation.

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- Remount the gear casing over-top the newly installed gear set. Before completely pressing the housings together, be sure the gear pins are in alignment with the spaces provided for them inside the casing.
- screw everything back together and remount the servo onto the brackets from which they came.

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