All right! You guys deserve an update 🙂
So, after this lens being largely replaced by a “new” EF-S 17-55 2.8 and I stuck at home during the COVID pandemic, I decided I would have a go with a screwdriver and see what was ailing my 18-200. I figured since I wasn’t using the lens because of the focus problem and I wasn’t super attached to it as the quality wasn’t great to begin with, I should give it a shot. If I messed it up, I could probably still send it in for repair or put it toward a better telephoto. If I fixed it, I’d save money (for a better telephoto) and I’d have an additional working lens.
I decided to go in through the front first, as my front element appeared to be loose and a lot of people with a similar problem on the Nikon 18-200 solved it by screwing the front element back in.
I carefully took the front element off and peered inside. There weren’t any more screws… so I got my airblower and finally took care of those nasty dust flecks always staring at me ever since I acquired the lens.
Unfortunately, I didn’t realize the front element is more or less “tuned” to the lens (with weird oblong collars and a sliding track), and I didn’t take a note on the position, but I screwed it on where I thought it should go (more or less)…
and decided to go in through the back.
YouTube was a big help here (though I have yet to find a “reassembly” video), and I carefully took out the screws and barrels all the way down to the front element again.
I had a good look at my focus mechanism, and I determined the cause of the sticking focus was a lack of lubrication—perhaps it dried up over the seven years. I got some white lithium grease and carefully coated the whole mechanism and then, using YouTube and playing with the lens like a puzzle, I put the whole thing back together again 🙂 .
The focus now works like butter, and the barrels (which were getting loose with age—there were a few loose screws upon disassembly), are now as tight as if I had purchased a brand new lens.
So! It looks like I’ll be getting some more life out of my 18-200.
If you want to see what the inside of one of these things looks like, I’ve attached some pictures.
