how easy to get spare parts for nikkor 300/2.8 af from 1988?

hoanpham · Expire: 2015-01-18

lens has serial 200189.
registered approx 1860 copies.
among the earliest AF version of this lens.

how much is it worth if AF is defected/jammed?

Esox lucius · Expire: 2011-11-18

Parts easily available at Nikon official repair/service agents, expect 1-2 week delivery time if they need to call Sendai and have some parts sent over.

Hard to say how much it's worth, when I don't know what's wrong with the AF. It could be as little as replacing a tiny part in the screw-driven mechanism or an expensive repair due to lens dropped and elements stacked on top of each other.

If it's in good condition it sells for about EUR 1500-1600. If it needs repair value is roughly [1500 minus (repair cost x 1.3)], few buyers want to gamble if they don't know lens needs simple or costly repair... Repair parts have same price globally but the cost of labour (repairing it) varies from country to country (also some repair agents add more premium on top of the parts prices they order from Nikon).

hoanpham · Expire: 2015-01-18

thanks Vilhelm,
the seller wants around 600 euros. manual focus is still possible, but uneven, and difficult. aperture ring does not click in.
i havent seen the lens yet, but can check if the price is ok to spend time.

Esox lucius · Expire: 2011-11-18

I can't decide on your money and I accept no responsibility if my theory turns out to be wrong but... If I were you I would buy it for EUR 600, simply because I think the repair cost will be a few hundred euros at most. Why do I believe so? Well,

Based on serial, your lens is from Nov-Dec 1986, making it one of the first AF 300mm Nikkors to leave the factory.
ref. http://www.photosynthesis.co.nz/nikon/serialno.html#300

Your lens is the screw-driven version, the lens screw that attaches to the camera AF gearing connector is located in the aperture ring (open rear lens cover to see the "half-moon" screw). This is different design than the subsequent AF-I, which had faster, built-inside lens AF mechanism.

"With the introduction of Nikon AF SLRs during the mid '80, the Nikkor 300mm lenses were inevitably being converted to incorporate automatic focusing mechanism. The original AF version of the AF-Nikkor 300mm f/2.8 ED-IF was an exact replica of the manual focus lens. It has a selector switch for AF and manual focus and two rings for presetting focusing distance. The major upgrade of the lens actually happened in 1992 where the AF-I Nikkor 300mm f/2.8 ED-IF was eventually incorporated a coreless DC motor which permits faster AF.
ref. http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/telephotos/300mm.htm

If the focus is stiff when lens is set to AF I am guesstimating that something is resisting the AF screw. The fact that you turn both lens and camera body selector to MF and focus is still stiff sounds weird, are you sure you have disconnected AF both on camera body and lens?

Since the AF screw connector is located in the aperture ring, and you have problems changing aperture... my theory is that the gearing connector in the aperture ring is damaged, and it prevents aperture ring from moving in circle (damage perhaps from forced twist, can happen with certain bodies) I believe the repair is not going to be a significant or expensive task to complete.

Let me once again point out that I take no responsibility if my theory is wrong and repair turns out to be more expensive than I thought.

hoanpham · Expire: 2015-01-18

Many thanks to Vilhelm.
I am appreciate a lot for your comments and PMs.