Nikkor 20-35mm f/2.8 loose barrel repair?

<p>My trusty old Nikon 20-35 zoom has developed a serious problem. I had it out on a hike in the mountains, and seemingly for no reason, the barrel developed a significant amount of free play which has rendered it unusable. Nothing happened, it never took a hit or fall. Just walking with it over a few days, I started feeling a knocking in the barrel which upon closer examination, is free play from the focal ring onward. With the lens mounted, I can rock the whole lens barrel up and down (a little under 1mm of play at the end) , as well as torsionally. The mount is tight to the camera, but as I said the play starts at the focal ring onward. It is so loose I cannot get a lock on autofocus. I suspect that a retaining ring somewhere may have come loose.<br>

Does anyone here have the same lens and had a similar problem and could shed some light? I can send it out to Nikon but my budget is tight, and I have some experience with disassembling manual focus lenses although autofocus lenses I'm a bit more wary of meddling in.<br>

Thanks,<br>

Greg</p>

<p>My best guess is that one or some of the lens internal frame screws has got loose. I had a similar issue in another lens (af-d) - from the day one. Finally several years after I tightened that screw. Meanwhile Nikon authorized service said that the lens is in specifications - no it was not, but I trusted them, then.<br>

You can allways send the lens in for service. It is also possible to open the mount side of the lens to see what you can do. Zoom lenses are beyond my limit though.</p>

<p>Back in the day, not so many years ago, when we had a competent repair person in our college town, the one thing he refused to touch were zoom lenses.<br>

I think this might be a clue that "home repairs" on such critters is ill-advised.</p>

<p>Lenses, even zoom lenses, are actually quite easy to take apart. That's not the problem.</p>

<p>Thanks for the response! I'm relieved, just found the problem and it's fixed. In all of 30 seconds. I was about to remove the mount and start checking inside, and found that every mount screw was loose, each by about a half turn. Was not expecting it to be that simple, but I'll take it :)<br>

It's interesting that with the mount loose, the mount end of the lens including aperture dial were 100% tight on the camera body, but the play started at the focal ring to the end. I'm not the first owner of this lens and I wonder if the previous owner had it apart for some reason and didn't properly tighten the mount screws. I've been using it about a year with no problem, and it only suddenly loosened up over a few day trip.</p>

<p>By trade I'm a master certified auto tech for 15 years (I know, that's not the same thing as a camera technician) but I'll admit I can be a bit stubborn to be defeated by ANYTHING in need of repair, lol. I have ended up in over my head in the past, now I'm a bit more careful to take my time and know when to stop with modern lenses, but I got lucky this time!</p>

<p>Good for you!</p>