[K-9]

I have a 135mm 2.5 Takumar lens. The large focus ring just spins freely without catching to actually focus. If you forcefully push it toward the top or bottom and then turn it, you can get the focus to move, otherwise, it just floats around in the middle. There is also what sounds like a small plastic piece inside the lens that you can hear when you shake it. It can't be seen within the elements, though.

I was just wondering if I opened this up, does it sound repairable or does that broken, chipped piece mean the focusing ring is shot for good? Thanks, in advance.

[Just1MoreDave]

Bayonet or M42?

[MattGunn]

YES it should be quite straightforward to repair.
I have not opened / repaired a 135 takumar but I have fixed a 55 1.8 and a 50 1.4 and I suspect the general assembly will be the same. The focus ring is usually secured to the focus mechanism with 3 small screws which can come lose over time. The rattling is probably one of these which has come right out.

Details of the disassembly and repair of a takumar 50mm 1.4 is described and shown pictorally here: Disassembly and Cleaning of the F1.4 50mm Super Takumar Lens

The site shopws a lot of tools for a complete repair but you should only need:
a suitable rubber bung or large cork to remove the trim (the ring with the writing on it),
a small cross point screwdriver to tighten the screws up,
a pair of tweezers to get the screw back in the right place.

The repair should be quite straightforward but if you have any trouble just ask.

[Just1MoreDave]

YES it should be quite straightforward to repair.
I have not opened / repaired a 135 takumar but I have fixed a 55 1.8 and a 50 1.4 and I suspect the general assembly will be the same. The focus ring is usually secured to the focus mechanism with 3 small screws which can come lose over time. The rattling is probably one of these which has come right out.

You're right, if the lens is an M42 mount, that's probably the issue. The K-mount "Bayonet" version is constructed differently, however. And this part is trouble for both lenses:

Details of the disassembly and repair of a takumar 50mm 1.4 is described and shown pictorally here:

Those instructions apply to a lot of Takumar and Pentax lenses but will not allow access to the focus ring screws on the M42 mount 135mm f2.5 lens. On those lenses, the whole front lens group unscrews. Just focus to the minimum distance and unscrew the barrel. I think (in this rare case, I have sold all mine) that you can see the three focus ring screws right there, though a long screwdriver is required. If not, this is at least the first step. It looks like there are grub screws around the focus ring; those might need to be loosened if you can't see the focus ring screws.

Like I said, the "bayonet" version is different. Although the front group unscrews in the same way, it doesn't get you anywhere. Peeling off the rubber grip allows you to get to three grub screws which affect the focus ring somewhat, but I don't think it's the whole story.

[K-9]

It is a K-mount, so does that mean it's going to be too much trouble? Oh, and it's a 2.8 not 2.5. Sorry. The only screws I see are around the bayonet and on the ring that covers over the focus scale (this part doesn't rotate). I don't see any way of opening the front of the lens, which has no wording or ring area, just a thin filter rim and built in hood. I suspect I should go into it from the screws around the barrel, between the focus ring and aperture ring, as I mentioned.

[wlachan]

1) Unscrew the filter mount retaining ring
2) Remove 3 screws and the filter mount
3) Tighten 3 screws sit underneath

[K-9]

Thanks, now I just have to go out and find one of those teeny little screwdrivers.