- Serpent S4113.0 - Sean Williams - Serpent Differential Build -

For a super smooth, bind free Serpent differential, Please follow my below Serpent Differential Build tutorial.

1. Dremel (Using the sanding drum w/light grit), Sand or file the sides of the Moon gears and bevel the lower half of the moon gears as shown. Spray Clean with motor spray to remove all dust and sanded debris.

2. Lightly ream both halves of the diff case as shown, just ream the outside of the diff half not the inside. Place the diff outdrive in the diff half to confirm it moves freely. Again one light rotation with a reamer should be all it takes to make the outdrive spin freely. Spray Clean with motor spray to remove any debris.

3. Replace the Black X-Rings with a 5x2mm Silicon O-ring, any 5x2mm silicon O-ring will work, your choice. Lightly lubricate then install.

4. Dremel (Using the sanding drum w/light grit) or cut about .5mm of material from the diff axel / x-shaft, bevel the ends as depicted in my below picture with a light sand. You want the x-shaft to move around somewhat freely in the diff housing, out of the box the x-shaft doesn't move at all. Clean with motor spray to remove all dust and sanded debris.

5. Take the 4 idler gears and lightly sand or dremel the edges of these idler gears as well to remove any burs at the edge as depicted in my picture, do not sand the bottom of the idler gears. Clean with motor spray to remove all dust and sanded debris.

6. Assemble as shown in instructions, fill diff half about half full and spin gears to work oil through out the diff half, fill remainder of diff oil to top of x-shaft and complete the assembly.