My HUb is a Nexus SG-8R31, 7 years and 3500 miles (5600Km) old. It has just developed a loud "clicking" noise when going forward, This happens both on and off the bike. It sounds like a broken ball bearing or pawl spring but I haven't dismantled it (yet). Has anyone experienced the same problem and found the cause of this clicking? Is it repairable or do I have to replace the whole internal assembly?
it has never had an oil dunk - but it is just about to get one. I have found out the cause of the broken hub! I decided to dismantle the hub and found the cause almost immediately - it is a completely shattered ball bearing cage on the non-drive side of the hub. Cost of a new one - less than a fiver. Great relief. So relieved in fact I have decided to service the hub myself and have sent for the special Shimano hub grease and "dunking" kit - at a cost of over £80! It looks pretty straight forward (hopefully not famous last words).