Tamron SP 60-300 loose zoom action

[SkedAddled]

Has anyone here found a simple & successful way to add some friction
resistance to the zoom mechanism of this lens? My copy is in overall
exceptional condition, but the zoom mechanism easily slides from its
own weight when tilted enough past horizontal. I'd also enjoy just
a small amount of further resistance in the focus twist action.

My initial thought was to wedge some cloth between the barrel sections.
I've been unsuccessful in this, and I don't know if it would stay in place.
The gap between the parts is extremely narrow.

If simple enough, I wouldn't object to some basic disassembly to apply
some heavyweight grease or other to the mechanism, but I know nothing of
the lens's construction, and I certainly don't want to do a major teardown
on such an excellent condition piece.

Suggestions, thoughts, experiences: all are welcome.

[Gardener]

Getting into the zooming mechanism almost always requires more disassembly than is practical.

[cooltouch]

I have disassembled and reassembled the Tamron 60-300 a few times. It's been several years, so my memory is a bit vague. Still, it's a fairly straightforward design and isn't really that difficult to take down. So, as I dimly recall . . . You start by peeling back the rubber grip on the focusing collar. This reveals the several "sliders" -- dunno what they're called, but they're nylon bushings with screws/shafts in the center. Since these are involved in the zooming action, I'd check them first, make sure they're all tight. Don't over tighten! To dismantle the lens, you need to start by removing the barrel sleeves -- tiny screws hold them in place. After that, I just figured out what to remove next. You should probably be able to figure it out without too much difficulty. Juust keep track of the order you dismantled things.

[visualopsins]

[visualopsins]

Example my ebay auction for 5 fungus throughout cheap zoom, each selling for $5-$15 in good condition in other auctioms, sold to Indonesia for more. Cheapest shippong cost was more than winning bid! Something tells me she cleaned them sold locally made a profit.

[SkedAddled]

[cooltouch]

Your mention of the tape jogged my memory a bit. I have run across instances in a couple different Tamron zooms where tape was actually used to locate the point of infinity focus. I have an AF 24-70 that has used this method and I ran into this in at least one other Tamron. Not sure it was the 60-300, though. It's more likely that the tape is covering up a screw that you have to remove in order to get further into the guts of the lens.

My lack of sufficient recall was bothering me so I grabbed one of my 60-300s -- the one I'd most recently dismantled -- and took a look. Down toward the base of the lens, above the aperture ring, there are two pairs of screws, roughly about 90 degrees apart from each other. Chances are these will have to be removed. After a bit of effort I managed to peel off the rubber grip. Now I see what you're getting at, and this jogged loose another bit of errant memory: the bushings I was describing I had found inside the focusing/zoom collars of the Vivitar S1 28-9 and 28-105 varifocal zooms. Because they're varifocal, as the zoom collar is moved in and out, these bushings travel through angled tracks that move the elements back and forth in a rather complex fashion. Obviously Tamron didn't do that with the 60-300.

On my copy, I pulled back the tape. I know this because I used Scotch Magic Tape to resecure the Tamron tape back to the collar. The Scotch Tape is holding up well, by the way. Anyway, my gut feeling is telling me you're gonna have to take loose those several screws on the collar and maybe even the tape to get into the lens.

Watching the zoom action, just looking down into the lens, it's looking to me like you're gonna have to pretty well completely dismantle it in order to get to the zoom track. Still, I wouldn't fret. As I mentioned before I've had the 60-300 apart a few times and it's a very straightforward design. This lens I have in front of me I completely tore down and removed all traces of lube, completely cleaning it in the process, then added back just enough lube to make it function properly, and reassembled it. The reason why I did it is because the focusing collar has this strange very fine gritty feeling to it -- like I was turning it across 1000 grit sandpaper or something. But I was puzzled to find that, after putting it all back together with its thorough cleaning and fresh lube that it still had that very slightly gritty feel to the focusing action. I'm still puzzled by this, and this is the only reason why I haven't sold the lens -- because I fear that the next owner will think I sold him a turkey. So I just keep it as a spare. Also it's worth noting that neither of my two 60-300s exhibit any zoom slippage or creep at all -- which is actually somewhat unusual with a push-pull zoom.

[Gardener]

[visualopsins]

[Gardener]

Basically, from my point of view, it comes down to cost of labor vs price. For example, today I completely disassembled a Canon 17-55/2.8, cleaned and put it back together. It took me most of the day, but based on market price minus purchase price it was a $250-300 job. A vintage zoom would be almost as much work, but it would not be worth my time. Now, if I lived in a place where market for vintage zoom were stronger and cost of labor lower, things could be different. So, I am willing to believe that somewhere like in Indonesia, for someone with enough skill to do the job quickly it may very well be profitable (practical). But not for a casual Western collector.

[cooltouch]

Gardener, if a person buys a lens to put into his or her personal collection, the time it takes to repair it doesn't matter, does it? Unless you bill yourself the hours you spent, or some such.

In this particular lens's case, if a person knows what he's doing, he can have the lens completely disassembled, cleaned, and reassembled in less than an hour. It really is that basic of a design.

[Gardener]

I do not bill myself, but I know exactly what my hour spent on repair is worth, and that's not an abstract number for me since this is how my collection is financed. So if a relatively low cost lens gets opened it's because I am interested to see what's inside.

As to your second point, if the OP knew how to handle it we would not be having this conversation, would we?

[cooltouch]

The first time I opened up a 60-300, I was at a camera show -- as a dealer. A guy came up to me and mentioned that he had bought a 60-300 from me at a previous show and said it had developed a problem, and wanted to know if I was willing to do anything about it. I took a look at it, said "Sure," and dismantled it right there in front of him. Fixed the problem -- an internal group had actually come loose, so I just dismantled it to retighten the group -- which involved opening it up pretty much all the way. Put it back together and handed it back to the guy. He was amazed I was able to make the repair right in front of him, and I recall thinking at the time that I was glad it had been so easy.

I'm not sure I understand you. So you determine the size or extent of you collection based on what your hourly repair rate is? Is that about right?

You know, a Tamron SP lens is a high quality lens. You may be able to pick them up for cheap nowadays, but that wasn't always the case, and they'd certainly been built to a fairly high price point. My first 60-300 I bought back in the '80s and paid over $300 for it from one of the NYC discount retailers. So even though the lens may not sell for much these days, it is still a quality item with a fairly high intrinsic value. IOW, it's worth being repaired, if for no other reason than its performance capabilities.

[Gardener]

I determine the minimal condition I am willing to acquire a lens in based on number of work hours I might need to spend to bring it back to acceptable condition. Unless I am interested in opening it up, then cheap beaters are my choice.

[SkedAddled]

I can assure everyone: I am fully capable of whatever mechanical aptitude
is necessary to delve into the inner workings of the lens's assembly.
Looking more closely, I've even found a few specks inside which could also
be eliminated through a partial disassembly.

I most certainly did not invite a debate over the merits and drawbacks of
disassembly of the lens in question.
I will respectfully ask the debate participants to either begin a new topic thread,
or take it to private messages, if the debate must be continued.



Michael, I thank you again for the provided information.
Based on your descriptions, I'm confident I could get inside the lens and reassemble it
without much trouble. At this point, it's simply a matter of deciding on whether to just
leave it alone, or go into it. I'll simply have to weigh my priorities about it.
On the one hand, I'd really like to firm up the action of it and remove the newly-discovered
dust specks, but on the other, do I really want so badly to open up such an excellent
copy of such a highly-regarded lens - ?

I'll think it over some more, repeating what I've already stated about posting more here
if I move forward with it.

[Gardener]

[cooltouch]

[SkedAddled]