DIY lens repair

I have this elderly 70-200mm one touch zoom. . . . .
The zoom / focus ring is very loose and I'd really like to improve the damping on it. I can't be worth the cost of repair, even by my nearby, really reasonable bloke. So I want to get an idea of what to do. Has anyone on the forum got any experience of looking inside this style of one-touch lens?

The front part of the lens will come off with four screws, around the periphery (there is no screw-in ring at the front as the big element at the front takes up the whole area). I can see the zoom slot in the barrel, through the front and I assume that, without the front section, the inner, moving elements would come out, along with the focus ring. I'm assuming some sort of damping screw can be adjusted.

yes I know what you're going to say but, looking on ebay, the lens is worth less to sell than it is to me as an fun mending project. Nevertheless, I'd like to have some idea about what I'm likely to fid when I get inside there. Natch, we're talking dust free environments and latex gloves. I do have reasonable success mending things in general - including camera stuff and I'm not a major clutz.

Any ideas folks?

To improve the damping, once you have taken it apart you'll need the correct grease. Acquiring it might be the most difficult part of the operation.

Perhaps peanut butter......?

But you're not dismissing the idea completely?

As a rule of thumb prime lenses are fairly straightforward to dismantle and service whereas zooms are a nightmare. That's not to say it isn't possible, just that your chances of getting everything back together are Kate Moss slim.

If it's a fairly cheap lens (and from what you say I guess that it is) then you have little to lose by giving it a go. Take lots of photos as you take it apart so that you have a reference when it comes to the hard bit of putting it back together.

As for grease, I use lithium grease which is perfect for lens helicoids as it's resistant to large variations of temperature and won't run - use it fairly sparingly and clean the old dry grease off first with a stiff brush (an old toothbrush with a drop of Fairy Liquid works a treat). You can get tubes of lithium grease from places like Halfords for around £1-2 and there's enough in a single tube to re-grease hundreds of lenses.

Good luck

Thanks for that info. I think I have a tub of Lithium Grease already.
The lens is hardly worth the cost of posting on ebay, in its present state but, if I could sort out this slop and keep it clean internally and working right, it should fetch a few quid. It is an f4 aperture right the way up so it has its uses - but it's not as gorgeous as my 60 - 250 DA so I won't miss it, either way..