Nikon 300mm F2.8 VRII Grinding Noise
#1. "RE: Nikon 300mm F2.8 VRII Grinding Noise" | In response to Reply # 0briantilley Nikonian since 26th Jan 2003Mon 04-Feb-13 07:39 AM
The VR system tends to make what I would call a "whirring" noise when activated, not grinding, but descriptions of sounds are notoriously difficult to analyse.
First, you might try to have someone with experience listen to the lens to verify whether the noise is normal. Second, just to make sure that it's the VR and not AF that is making the noise, switch VR off at the lens and see if the noise goes away.
But if this noise has only just started happening, it may be time to have your lens looked at by a service shop.