Rear Hub Motor Removal and Service of Planetary Gears

Tools/ parts required:

18mm wrench
3mm hex key or T20 torx safety bit
Mallet or hammer
Wood block
Zip ties
Cutters
Grease
Tri-flow lubricant
Pliers 

Remove the chainstay pad, cut zip ties, and carefully disconnect the  main power cable from the rear hub motor.

Position the shifter in the high gear (small cog). 

Use a 18mm wrench to loosen and fully remove the axle nut and flat washer from the drive side. 

Next use a 18mm wrench to loosen and fully remove the axle nut and flat washer from the non-drive side. 

To drop the wheel out of the frames’s drop-out use a 10mm wrench (or cresent wrench) on the axle flats and slightly wiggle the axle while pulling back on the rear derailleur.

CRITICAL: remove any inside spacers, and anti-spin washers. Keep the drive-side and non-drive side spacers separate and note the order and orientation of the anti-spin washers and any spacers.

Carefully remove the six cover plate bolts from the hub shell. 

(3mm hex tool or T20 torx safety bit may be required). The free wheel does not need to be removed in order to access the motor. 

Note: If the freewheel needs to be replaced, it should be removed with a Shimano freewheel tool before the cover plate is removed. 

To remove the motor core tap firmly on the non-driveside of the 12mm hub axle with a mallet or hammer to dislodge the motor core from the hub shell.

The internal motor with power cable, and planetary gears can now be separated from the hub shell.

Note: The planetary gears and casing may stick in the hub shell when the motor is removed. The gears can be removed by hand or tap the wheel against a hard surface to dislodge the planetary gears from inside the hub shell. Ensure the metal key-way that mechanically locates the gear case on the axle is not lost. 

Examine the hub shell / motor/ gears for issues such as:

Cartridge bearing wear

Note: Bearing code on seal (i.e. 6002RS/6003RS)
The two cartridge bearings can be serviced by removing the lip seal or the complete bearing can be replaced.

Hall sensors failure
Cracked plastic sensor mounts may be fixed with epoxy. A Voltbike technician repair may be needed for sensor replacement if the motor is getting power but not turning.

Burnt or signs of corrosion
Electrical power seems ok may motor will not turn or seized. Check for burnt wiring or serious internal corrosion. Voltbike technician repair may be needed or motor replaced.

Speed Sensor magnets debonded from inside cover plate
New rare earth magnet of same shape and size can be rebonded in place using epoxy or super glue. Ensure the magnet’s polarity orientation is correct. Signs may be incorrect speed reading. 

Damaged or fluctuating power cable
Voltbike technician repair may be needed to repair or replace the main power cable through axle into the hub motor. The power cable may have a bad connection from being
twisted or cut. 

Broken or cracked nylon planetary gears wheels x 3
The gears and metal casing can be removed from the axle by firmly tapping the internal motor assembly on a wood block to drop the gears off the 12mm motor axle.
Ensure the metal key-way that mechanically locates the gear case on the axle is not lost. 

Note: If the electrical motor is working but slips, grinds, with excessive noise when under load or climbing. Examine the gears carefully for cracks or damaged teeth.

Squeaky/seized planetary gear metal case
Lubricate the center of the metal gear casing using a high quality penetrating lubricant such as Tri-Flow. The center disc only rotates one direction and will normally have some resistance. 

To reinstall a new or used set of planetary gears
Align the planetary gear casing with the key in place and firmly and evenly hand press the gears onto the axle. ( 2mm gap) Lightly grease the three nylon gears and ensure the unit seats correctly in the hub shell when reinstalling the motor. 

Note: Approximate 2mm gap between motor and gears when pressed on firmly. 

Once the repair or replacement is completed, reinstall the motor and ensure it is fully seated in the hub shell.

Reinstall the cover plate and tighten six bolts (star pattern) using the required tool.

CRITICAL: Check all washers, spacers and anti-spin washers on the drive and non-drive side are correctly positioned. 

Align the rotor with brake caliper and reinstall the rear wheel in the
frame.

Use a 10mm wrench to align the axle flats with the drop outs.

Once the wheel is seated fully in the dropouts the axle nuts can be tightened with an 18mm wrench. The rear wheel should be centered in the frame. Ensure the axle nuts are very tight and re-checked after ten hours riding time.
Align the power cable plug arrows, firmly connect, and secure the power cable with zip ties or chainstay pad.

Test ride to ensure the bike is safe and functioning properly!