Canon FD 300mm f4 Front group dissasembly

[Bah]

Hi,

Hoping I can get a little help here; I bought a 300mm fd f4 which had some fungus in between the front elements and a stuck apature.

I cleaned up the apature no problem, but after removing the back half of the lens containing the focusing group, I can't for the life of me seperate the front element group, as far as I can work out it should just unscrew as shown in the photos?

Ps, focus was sloppy as the focus guide pin was missing its rubber coating (similarly to my 24mm f2) and a bit of polyolphelin heat shrink over it was perfect, I'll see how it holds up in the long term.

Appreciate any help.

[Bah]

Can anyone please suggest where I might have the most luck getting some help on this? Rangfinder forum?

Cheers

[Bah]

Being impatient and having an idea, I put my lens in the freezer at about -21c, took it out and hit the thread area with a hair dryer on full till it got hot to the touch; bit of elbow grease and presto, VICTORY!

[mo]

I am glad you got it sorted and posted your solution.

[kanon]

I know this is a very old posting but how was the aperture mechanism accessed for cleaning?

I have a FD 300mm f4 with stuck wide open aperture blades. Not sure whether to dismantle from the back or the front of the lens. Have tried to unscrew front section of lens barrel but its stuck tight.

Any suggestions?