DIY 35-70/2.8 Repair

Discussion in 'Nikon' started by bernardmiller, Oct 24, 2006.

  1. My beloved (and extremely sharp) 35-70 non-D has developed a case of element
    fogging/fungus. Can't quite determine what it is, but something in there is
    obviously hazy and I'm getting a lot of flare.

    This is a real hassle, as it is my favorite lens to use on my D70 in most
    circumstances.

    I priced out a repair at Fixation of London (where I am currently residing), and
    it could run up to as much as 170 pounds (roughly $330) to fix. I can't afford
    that, especially considering the age/value of the lens. I can't afford to buy a
    similar lens from KEH when international shipping is included. I *definitely*
    can't afford a 28-70 AFS, which I am lusting after. And I don't want to spend a
    nearly equivalent amount (actually, over here, a lot more) on a third-party lens
    if it doesn't perform as well. Plus, I have a couple of other items of equipment
    that need fixing that I know I'm going to need to fork out some money for.

    Finally, I have no compunction about taking apart things and fooling with
    them--I enjoy learning how things work.

    I can get a replacement element for 40 pounds from Fixation. That I can afford.
    I've got a bit of free time at the moment. And I'd really like to get this lens
    working/replaced. At present, it's screwed, so I don't think that ripping into
    it is a terribly foolish or risky proposition at this point.

    So how hard would it be for me to attack this sucker myself, with any reasonable
    probability of success? (I'm not easily discouraged--I consider at least a one
    in eight chance of doing it successfully to be good odds.) Any advice anyone can
    offer? What is the procedure for disassembling the lens? Beside a spanner
    wrench, are there any other specialized tools necessary? If this is an utterly
    quixotic proposition, can anyone recommend a very good and reasonably priced
    28-70/80 2.8 lens (yes, it's got to be that fast--I shoot in low light quite
    often) that I should consider looking at new?

    Thanks in advance for any advice you can offer.
     
  2. Bernard:

    I have knocked down a few lenses in the past as well as having owned the lens in question - I myself would only tackle it if it's deemed worthless - I suggest selling on ebay with all issues disclosed & then simply buy another lens without problems - this lens is available in my opinion for a very good price usually. Way undervalued for what it's capable of.

    Good Luck
     
  3. Also:

    Here's a link with a large file of a pdf of the exploded parts drawings for reference:

    http://www.thefotogeeks.com/diagrams/nikon_lenses/AF35-70mm2.8D.PDF
     
  4. Completely agree with Lee. Had an old beater Leica M3 that the shutter finally gave up and I contemplated selling for scrap but put it on eBay instead with complete disclosure. Netted almost $500! Much better than the $50 offered for scrap!

    I would certainly give it a try, there is always someone out there that wants a quality lens and is capable of fixing it. Meanwhile you can fund the new acquisition.

    Ron
     
  5. ShunCheung

    ShunCheung Administrator

    Somehow this particular lens is very prone to this problem. Mine, originally purchased back in 1990, developed this same problem around 2002. Knowing that Nikon USA repair would charge me a lot for fixing it, I took it to my local repair store. Unfortunately, they wouldn't touch it and suggested that I sent it to Nikon for repair.

    So I suspect that the reapir job might not be simple. If you lack the tools to re-align the elements precisely, you may have problems putting it back together in perfect condition. But if you are in a "having nothing to lose" mode, it may be worth a try.
     
  6. I believe that the systemic problem with the 35-70 non-D is a breakdown of the 'glue' between two elements in a group. I've heard this somewhere along the way, but I can't find any references to it just now.

    You might find that you can clean up and re-glue the elements yourself, presuming you are capable of that level of disassembly / reassembly.
     
  7. I second Lee's counsel. I once tried to similarly clean a cheap, seemingly simple, Pentax zoom...and discovered that zooms can be REAL tricky. The instant that I removed the front lens element, some kind of long bar that ran the length of the lens interior slipped off of the element's housing and slid back into the lens. I had no clue where it connected on either end, and could not get even the front element back on while preserving all lens functions.

    So I've successfully disassembled and cleaned more than one 50mm prime....but now leave zooms alone!

    Sincerely,

    Dave
     
  8. Never been in this specific lens, but as a general alert: it's quite easy on some Nikkor zooms*
    to slice right through the flexi-pcb that attaches to the mount contacts.

    *and presumably other lenses
     
  9. Thanks for all the responses--and thanks especially to Lee for the diagram.

    Yoiks! That is one Rube Goldbergian piece of equipment. I knew zoom lenses tend to be pretty complex, but there appear to be well nigh over a hundred parts, exclusive of a buttload of maddeningly tiny screws and various washers/retainers.

    I think I will try Lee's sage advice, and attempt to sell it for some small sum on eBay. If that does not work, I may fool around with disassembling it just to see how it ticks--I doubt that putting it back together is going to be a successful proposition. It is certainly a daunting one!
     
  10. I bought an older non-d 35-70 on e-bay, got a great price, but I was quite dissappointed when it arrived to find it had a case of fungus. The seller was clueless about photo equiment, and the lens looked almost pristine other than the fungus. I took it to a local camera repair shop, a local "one man" shop and the owner offered to clean it for $40, so I took him up on it. He did a great job and the lens has been clear for almost two years. It stays on the my D-70 almost all of the time now, this is a great lens.... I would look around to see if you can find a smaller camera shop which may be willing to clean it up for less than a hundred or so.
     

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