Canon 70-200, f4: clacking noise when shaking lens?

Non IS? IS frequently can make noise depending on brand and model.

Here's an easy test to tell if it's something that's "not good".

Rather than shake it - which is really rather subjective, simply and gently turn it end over, end over.

You really shouldn't be able to "hear" anything, and at most "feel" something.

I had my hands on a 70-200 f4L frequently a few years back, and never noticed anything other than a rock solid little lens. I also discovered I needed IS really badly.

My Sigma 70-200 f2.8 OS doesn't have any movement at all inside - even when I "shake" it. My EF-S 17-85 makes a slight deep clunking and something shifts, my Sigma 17-50 f2.8 OS I can hear a bit of a super slight light sounding clunk with no movement. And I have to shake it end to end, not side to side.

I've always wondered what possesses people to shake their lens to begin with? I'm wondering how many lenses are traumatized by "shaken lens" syndrome? Was the lens crying and you tried shaking it to get it to shut up? Bad day at work?

Honestly folks, seek out help before you hurt any more optics.