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05-29-2011, 04:55 AM   #1
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Vivitar push pull, how tight should it be?

So my latest ebay lens is a vivitar 35-70 2.8-3.8 push pull lens. It's in nice condition but the focus was a bit stiff and the push pull was very stiff. The push pull was stiff enough that I was afraid I was going to rip the mount off operating it. There doesn't seem to be much info out there on this lens or vivitar pus pull lenses in general (in fact what I did find was threads saying there doesn't seem to be much info available on it). The stiff push pull did seem to be a common problem though.

To cut to the chase, how stiff should these lenses push pull be in good working order? The lens is very fluid and tight (I don't think there is anything wrong with it except maybe old dried grease). It't almost like operating a hydraulic cylinder, being very smooth and fluid but its like its hydraulically dampened. So I tore it part way apart, wiped away some of the old grease and wiped in a little new in select accessible areas and it improved some). If I operate it very slowly it takes a lot less pressure now but fast is out of the question and either way its till like trying to operate a hydraulic cylinder.

So what should my goal be here. Is slow the way these are designed to work. If I can manage to tear it further down without trashing it to just clean it and lube it, what type of operation should I be shooting for? Should it be able to get to the point where it is very easy to operate and can be operated fast or did these lenses never operate like that?
On a side note I did a lot of searching on what lubricant to use. The stuff I used is very thick which may be why it didn't help a lot (its what I had on hand though). I'm thinking of going ad buying something better but will that do any good?

05-29-2011, 05:00 AM   #2
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It should be no where near as stiff as you describe. My old push-pull zooms were very easy to zoom with.

Tim
05-29-2011, 05:12 AM   #3
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In that case maybe a more thorough tear down is needed then. I'll try to clean all the old grease out and use a modern grease. Thanks for the info.
QuoteOriginally posted by atupdate Quote
It should be no where near as stiff as you describe. My old push-pull zooms were very easy to zoom with.

Tim
05-29-2011, 05:39 AM   #4
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Try working it off the camera for a while. The lenses were supposed to be a little stiff new but they got loose in a hurry.

05-29-2011, 05:40 AM   #5
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I guess now the question is what kind of lubricant to use? It't not worth spending 40$ or more shipped on over priced helical grease (not for this old lens). Is there a more reasonably priced helical grease? I'm tempted to just use something I have (I have shelves full of chemicals including several lubricants). I was thinking of cleaning with g96. Its an all in one cleaner, lubricant, protectant like wd-40 without the disadvantages. It will not gum up or foul and leaves a very thin lubricant layer. I have used this on firearms (what its designed for) many times and it is ultra high performance. It has been heavily stress tested by the US and Canadian military and performed very well. Of course I'm still thinking it might not be such a good idea to have it everywhere like that. I could follow with (or just exclusively use) penzoil 100% synthetic white marine grease . I have a tube that has been sitting in a box for at least 10-15 years and there is absolutely no sign of oil separation.
Any other suggestions? Searching found that there is no general consensus on what to use and all kinds of different recommendations. Leica actually recommends Vaseline of all things for a field lubricant.
05-29-2011, 05:42 AM   #6
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I did and while it freed up a little it was still incredibly stiff. Working it off the lens after the partial relube helped a little too but again not near enough.

QuoteOriginally posted by Lowell Goudge Quote
Try working it off the camera for a while. The lenses were supposed to be a little stiff new but they got loose in a hurry.
05-29-2011, 05:20 PM   #7
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So now that I'm in the process of destroying my lens, does any one have any advice how much grease to use? I have all the glass and about 2/3 of the metal off. Whats left is 3 rings with helical type cuts in it, a brass base and the mount. I couldn't tell how to get the rings apart. During a moment of insanity I cleaned out the 3 rings with brake parts cleaner (supposed to be safe on plastic and rubber though it all seems like metal). I started with a few little dabs of grease but it doesn't seem to be spreading around much?
05-29-2011, 05:57 PM   #8
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Hi ripit,
I have a similar working one here (actually an Ozunon) and a dismantled donor one.
The push/pull and rotation is fingertip light.
There is only a light transparent smear of black grease in the scroll slots
and it has not dried over the years.
If the lens had been dropped,like the one here, maybe one of the
3 little white nylon rollers in the rear element group has broken and jammed in the scroll
so the roller action no longer works properly.
If yours is like this one, when re-assembling, the infinite focus might be off
that is adjusted by re assembling with the focus helices in a different place.
It has to be exactly right or the lens won't work.

05-29-2011, 06:24 PM   #9
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thanks for the info. I was going to try my chances with just a little grease so I'm glad that was right. By the way, everything was in very good condition inside. The rollers are all intact but the grease was very thick and dried. In fact, even with all the grease washed out with brake parts cleaner, everything moves slick as could be.

Now for the hard part, putting it back together. it seems I have something off with the rollers during reassembly. not only are there shorter and longer rollers, but there are shorter and longer screws on the longer rollers. I thing I got them mixed up. I'll just have to play with it.
05-29-2011, 06:27 PM   #10
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The one here has double rollers and longer screws on the rear lens element ( times 3)
05-29-2011, 06:33 PM   #11
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That helps some (one step closer), thanks. Out of curiosity, does yours have 10 rollers total that go somewhere on this rear 3 ring assembly (and 2 that go to the front assembly, focus ring if I recall right)?
05-29-2011, 06:39 PM   #12
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2 nylon rollers on the front element ( under the rubber grip), they are 3 mm outside diameter.
As I recall, they go in last thing, after the focus helices are aligned.
Aligning the focus helices and getting those rollers to line up, nearly sent me nuts
05-29-2011, 07:18 PM   #13
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one obstacle down. the four helix groves at the far rear are different (one set is longer) and the ring was indexed wrong. I got the back 4 in now and functioning. Front 4 went in fine too. Now, the big questions, is why do I have 2 rollers left (not the 2 that go on the front focusing helix). I took them out in groups kept separate so these 2 go together somewhere.

the first time I took it apart I didn't go near this far (gave up after all the trouble I had with that stupid focusing helix).
05-29-2011, 07:50 PM   #14
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I got the whole rear assembled and working fine. I have done the front before so there shouldn't be any issues (probably plenty of difficulty with the focus helix and adjustment bot no issues of not knowing what to do). Its nice and smooth and easy now (focus and zoom).

@wombat2go, thanks a bunch. I was about to temporarily give up there for a while. I don't think I would have figured out that the longer screws go to the element. I have to wonder if it would have functioned fine with the screws reversed but then broke as I'm guessing moving the element causes more pressure that just sliding along another helix ring.
05-29-2011, 08:20 PM   #15
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I set the focus screws temporarily to the same point they were before, and what do you now, its at the right point. Its still kind of stiff now that its all together but its a drastic improvement over what it was before. Maybe down the road I'll try a little more grease. It was a pain in the but but a good learning experience.
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