Thanks to Blog reader Simon, we have the following article, for the disassembly and repair of this F zoom, which is IMO optically excellent:-
Disassemble the Old Takumar-F 28-80 Zoom Lens
Disassemble (and Repair) a DA* 50-135!
Repair a Stuck SDM Yourself!
Disassemble a DAL 18-55
Wednesday, January 12, 2011
Disassemble the Pentax-F 70-210 Zoom Lens