We have a Singer T&S Special Zig Zag model 648 bought in 1970. The upper vertical shaft gear has been ground down and runs rough and will not turn the bobbin. There are two part nos., 163328 and 163987. Are these gears the same, thus interchangeable? And are there any tips or techniques on changing this bevel gear on the end of that shaft? Or diagrams? Thanks.

Roy, July 2008

Hello Roy,
There is only a slight difference on the gears and they are very easy to get, if you e-mail me and remind me of your model and problem I will type up step by step and attach it. What country are you in ?
Ken

drivewithken@blueyonder.co.uk, July 2008