Difficult to turn aperture ring

[jfoote]

I just got a nikkor 24 f/2.8 ais. Glass looks great, focus is buttery smooth, the aperture ring turns fine when it is not on the camera. However, when I mount it, it needs more force than my other ais lenses, is more difficult to remove but most problematical, the aperture ring is very difficult to turn when on the camera. My other ais lenses work fine - no issues with turning at all.

I've tried it on an F3, FM and N90s. No problem with any other lenses on any of the cameras.

It seems if I could shave off 1mm of the aperture ring, it would be fine. (I am not about to do that.)
Any suggestions for a fix?

 

[John Koehrer]

It could very well be the lens was dropped and the mount slightly bent. This would make mounting/dismounting more difficult.
When the lens is mounted, the lens mount may push it forward just enough to bind.
I'd check the distance from each of the ears on the mount to the forward surface. Pretty easy IF you have a caliper. If no caliper,
a precision scale may work not to get a measurement but to compare the gaps.

 

[Alan Gales]

Are the screws nice and tight on the lens mount ring? If the head of a screw is sticking out just a wee bit it would affect things I would think.

Since it only happens when the lens is on the camera I'm thinking John may be correct and it's the mount.

 

[David Lyga]

Yes, are the screws tight?

Or ... something is hitting the mount chrome and I think that it is probably a slight bend in the aperture ring that is causing the friction with the camera's mount chrome. Take a magnifying glass and inspect the mount area on that lens very carefully. - David Lyga