Originally Posted by
Reynolds
Don't know about the slipping, but I have a Nexus 8 with 13000 kms and it always felt like grinding in 4th gear. No problems so far, Shimano says it's normal to hear noises in all gears in certain circumstances:
SHIMANO Dealer's Manual / User's Manual
I have a bike with 7-speed Nexus since 2007, no lubricating, no servicing, no problems...
Although, to be honest, I never rode that bike so regularly, more like once or twice a year for couple of weeks, and rest of the time it's stored in a garage.