Nikon zoom probs?

[Blighty]

Fellow Apuggers,
I was using my 20-35mm f2.8 AFD Nikkor the other day. When I switched the lens back to manual focus (using the button on the lens), the focussing ring refused to engage with the focus gear. The focus ring just kept turning and turning. Normally, a quick twist either way of the ring engages the focus mechanism. Eventually. it worked, but now I'm in the position of not wanting to use it on AF again, just in case the same happens again. Anyone had a similar problem? Regards, Blights.

 

[fschifano]

No but it sure sounds like the lens needs some repair. Any chance that it is still under guarantee?

 

[Steve Muntz]

I had that lens but no problems with it, and do have an 80-200 f2.8 with the same auto/manual focus switch. That lens doesn't lock into either mode anymore so I use a piece of g-tape to hold it in place. I think they may have had some problems with that design so newer lenses don't use it. This doesn't include the 85 f1.4 which is still available with it, but an older design and possibly the 28 f1.4 but I haven't used that one.

 

[John Koehrer]

I don't remember the internals of that particular lens but it sounds as though it needs a CLA. There's most likely an idler gear that rides a shaft & the lube has lost it's lubosity & just needs to be cleaned.
Just as a curiosity, does it fail in the same manner whether it's warm or cold? Or does it work when it's warm?

 

[Blighty]

Just as a curiosity, does it fail in the same manner whether it's warm or cold? Or does it work when it's warm?

It was fairly cold when I was using it (it's always cold in our house!). There doesn't appear to be anything loose inside it. On the plus side, I think I've only ever used it on AF around 1/2 doz. times in the ten years I've had it. I always thought That AF on wides was a bit of a waste of time. Still, it'd be nice to know that it functions as it should.