Tokina 500mm Mirror Lens Focus Seized-up
This might be helpful
https://www.flickr.com/groups/strobist/discuss/72157604235612536/
https://www.dpreview.com/forums/thread/2554136

Thank you for taking the time and trouble to follow-up.
I found more detailed information about dismantling the lens on the Pentaxforums website and managed to take it apart sufficiently to gain access to the helical thread. There, I applied heat from my wife's hairdryer, which persuaded the thread to move, albeit rather stiffly. I have applied some silicon gease, hopefully to prevents it seizing up again, so hopefully it's fixed.
Regards
longbo
Member
Anyone know what could have happened? Does anyone have disassembly instructions so I can have a go at fixing it?