AF-S Nikkor 17-55/2.8G fix?

[Dreadnought]

Hey guys,

I've got a 17-55 f/2.8 with a sticky aperture rotator. I've disassembled the lens down to the rear optics barrel, but I don't see anything obvious thats causing the slow moving aperture. The blades move very freely, and theres no oil residue Anyone ever have something similar to this happen or know any lens maintenance forums/resources?

Thanks!

Brian

[jdepould]

The 17-55 doesn't have an aperture ring ...

[Dave C.]

Originally Posted by jdepould

The 17-55 doesn't have an aperture ring ...

+1 this is exactly correct

[Dreadnought]

Im talking about the internal one...

If you remove the rear mount, and the rear lens, there is a ring for the aperture held in place by a snap ring. I removed the snap ring and the aperture moved quite freely after that. I did manage to find one of the aperture return springs out of place. I didn't know if anyone had any internal lens maintenance experience here.

[OsmosisStudios]

Not likely.

[RLucas]

Since you seem to be much like me, and don't mind taking expensive stuff apart and going the DIY route, here is a link to a pdf for that particular lens. I was hoping to find a free one, but this was the only one I could find. Hope this helps!
Nikon AF-S DX ED Zoom Nikkor 17-55mm f 2.8G IF Service Manual Repair Guide - Download Technical

[jdepould]

How did you diagnose the slow aperture in the first place?

[Dreadnought]

Luke, thats awesome!

I was getting overexposed images at anything higher than say f/5.6. While the lens was removed, i flicked the aperture control lever on the back on open it up, and saw that it very slowly returned to closed. I figured there was something gumming up the works.

I actually managed to fix this lens. A good Q-tip and alcohol fixed the f-stop issue for the most part, along with re-seating the aperture ring and the return spring (one of the two wasn't connected properly). the lens had been banged around quite a bit by its previous user and the focus ring was near impossible to turn. a hammer and a punch got the focus ring from an oval to a circle again. the whole lens functions like a new one now. pro glass is tough, but definitely not bullet proof...

thanks again for the data luke, it was invaluable!

[jdepould]

That's crazy! Were you able to check the condition of the weather sealing? I'd be worried about dust and moisture.

[Dreadnought]

the seals looked to be intact on the lens mount ring, and the final optic glass, but there arent any between the focus and zoom rings, just really close tolerance machining..

when you adjust the focal length, you can feel air blowing in your eye through the viewfinder, so dust is going to get in there eventaully. I reckon it just takes regular preventative maintenance to keep it from accumulating. I dont think it would get into the optics barrel, but it would probably make its way into the focus/zoom assembly.

BTW...the AF-S drive doesnt seem to be any more that a rather large stepper motor. It looked to be pretty robust, with the control electronics associated with it probably being more prone to failure. Overall, a pretty good design. This lens had a pretty rough life, so under the circumstances, im really surprised thats all that was malfunctioning.