videoranger
Wore out three sets of tires already!
I had this inquiry as a private message, but thought I might as well start a thread about ND DD and D conversion 2 speed service so others can share their experience with these hubs also. When these hubs are in good condition they work very well but there are some parts that are prone to wear. I've included some pictures and a scan of the ND info with parts list. If you are working on one of these for the first time it helps to look at the parts list to become familiar with the assembly before taking it apart. These are pretty simple, but it might help to lay the parts out on the bench in order of assembly as you take apart for easy reference. No special tools are needed except for the one that fits the sprocket set nut as pictured. After cleaning all the parts inspect all bearings and races for excessive wear. always replace damaged or pitted bearings if needed. Inspect the sliding gear that moves with the push rod and look for damaged gear teeth. The teeth can show wear and chipping especially where the gear engages with the driver. The toothed part of the driver that engages with the sliding gear can also become excessively worn. These conditions can cause slipping under load and damaged gears should be replaced. The push rod has very tiny fine threads that hold the slider gear parts to the rod and these can become damaged also. The push rod has a tapered lower end to fit the 2 gear holder parts as pictured and over time this can wear so that there is excessive play in the gear on the rod. The axle will also wear as the gear slides and excessive wear will cause a poor fit of the gear on the axle. Inspect the three planetary gears for any damage as well as the driver toothed surface that engages with the planetary gears. chipped gear teeth require replacement. Note in the ND diagram that the coaster brake parts are the same as the single speed and are serviced the same. The reaction disc is also pictured and is needed to be in place on the sprocket side of the hub to keep the internal parts from getting too tight during normal use and braking. Make sure the slider gear can fully engage with the driver when the rod is pushed in by the rod and can fully disengage with the inner toothed bearing race that is on the axle. Wear on the push rod taper can cause the gear to not fully disengage from the bearing race gears and this will cause poor operation and damage the slider gear and the teeth on the axle bearing race. I hope this makes sense. Parts of course are getting real hard to find. If anyone has some other repair advice, please add to this thread. These hubs should have positive shifts with no jumping out of low gear when pulling hills. The shift cable should not be real tight when the bell crank is not pushing in the rod and the spring inside the cable adjuster keeps excessive load off the rod when pushed in. If the hub is in good repair and not subjected to harsh use it can last for many miles.Onewheelsqueel said:
