28mm f/2 lens-ring w/aperture setting dot loose, moves ~15deg each way.

[disambiguated]

I'm experiencing a weird problem w/my 28mm f/2 lens - the foremost 'ring' of the lens, where the aperture setting dot is located, now has ~15 degrees or so of play in it, left-to-right.

Has anyone run into this before? The lens still seems to function and aperture setting is correct, even if the aperture dot is a bit cockeyed, but this obviously isn't optimal - especially as the hood for this lens is large, and having it sitting at an angle both looks dumb and can take up more space in the lower-right corner of the viewfinder.

Is this something an ordinary mortal can somehow fix, or does it require repair by a Leica lens specialist?

Clue greatly appreciated, many thanks!

 

[disambiguated]

Never mind, I figured it out - there are three tiny flat-blade screws on the foremost ring, and they'd somehow slipped loose. I simply aligned the ring properly so that the aperture dot was 90' vertical, then tightened each of the screws with a Philips Head 1.4 screwdriver, and that fixed it.

 

[GrahamWelland]

This is a very common problem with the 28/2 front element. The other is that the lens hood has a tendency to fall apart also where the plastic front element will detach or loosen against the mounting ring. This happened to both myself and another friend with the 28mm. There's also some school of thought that it's the lens hood also that contributes to the front element coming loose too - are you using the hood and/or fixing filters regularly?

I would recommend checking your lens for ultimate sharpness after your fix. I had a local shop tighten the front element and noticed some degradation in the performance of the lens compared to another copy (when pixel peeping). I decided to send mine to Leica for CLA & critical adjustment as it was still under warranty.