Shimano Nexus 7 (sg-7c22) servicing...

[El C]

I have a little problem with that hub, it´s making a pretty loud rattling noise now and then.
Brakes ok and even pedaling is pretty much ok most of the time, but the rattling says that something´s not right. And I don´t mean the rattle that the gearing makes, that´s the normal noise.
When I hold the pedals stationary and move the tyre as I was backing it jumps every now and then.
What do you think it is?
That one ring looks like it's broken and a piece is missing.
Pics show how it looks like.

 

[RustyGold]

I have three bikes with nexus 7 speeds, and they all feel like they jump teeth when rolling backward with forward pressure on the pedal. I assumed this is normal as they all do it, and it doesn't jump/skip under normal riding conditions no matter how hard I get on it (assuming properly adjusted). It could be that they are all bad as they all came on used bikes that were 15-20 years old when I got them .

 

[Starnger]

Rattling while going backwards with the slight tension on the chain is normal for Nexus 7, it is even mentioned in the manual. So don't you worry