Futaba 9253
Click on the small pictures for a larger view

Repair Futaba gearsets  
Some servos are very expensive, so when you break one, it's nice to be able to fix it yourself. Most servos have gears and servo cases available. This can save you a lot of money. It's nice to know what you're up against when you crack the case open. I hope this helps.

Replacing the gears is the easiest repair by far. Just take the top off, carefully remove the gears, clean up, regrease and reassemble.

  • John Rice suggests counting the number of turns when removing the screws. This is to prevent stripping out the holes in the servo top. Whether you count or not, be careful.

We do have servo grease in the Tools/Lubricants section of the store, so it's best to thoroughly clean the gears before reassembly. Warm water, dishwashing soap and a toothbrush work well for this. Be sure to stop the drain hole in your sink, just in case you drop a gear. Don't use hot water, as it could warp the gear.

Replacing the whole case is more complicated. Typically, it's only the top that needs to be replaced. Be careful not to ruin the rubber seal when you remove the top and bottom of the servo. Some of components are a little difficult to remove, but it can be done. Be careful not to ruin the rubber seal when you remove the top and bottom of the servo. See the Tip below.

The gear train.

This is what you see when you pry the bottom off a 9253.

Tip

When reassembling the servo, roll the rubber seals over the center section of the case. Then put the screws back in and run them in, but not all the way. Leave enough room for the seal. Roll the seal up or down into the groove, then tighten the screw.

The white material appears to be a white silicone sealer. I would think that it would be wise to renew this when you reassemble the servo after changing the servo case. Don't just go down to the hardware store and buy some bathtub sealant! Some silicone sealers are very corrosive. You need to get electronics grade silicone sealer.
This is the top of the servo after all the gears are removed. Note 9151 is molded into this 9253 case. Quite a few parts are interchangeable between Futaba servos, but be careful.

This is the top of the replacement case for the 9253. Note 9203 is molded into the case. Quite a few cases are used for more than one servo model. However, they aren't necessarily interchangeable across models. For example, the 9203 case might not work with the 9151 servo, however, a 9252 case top is compatible with the 9251.

The gears below are available separately from the online store.

Caution

If your servo doesn't act just like a new one after you work on it, you should find out why, or send it in for professional repair.

9253 1st Gear

9253 2nd Gear

9253 3rd Gear