Pfaff 130 Frozen Zigzag repair

The 1951 Pfaff 131 is in very good condition. It worked fine except for the fact the zig zag dial was frozen.  Probably caused by old oil solidified on the dial shaft. 

Here I have removed the dial. It comes off by undoing a set-screw in the lower part of the dial. The slot in the shaft is just a slot you can use later to find the correct position for the dial on the shaft.

Even soaking for several weeks in penetrating oil and brake cleaner didn't free the shaft.

This is the rear of the mechanism. the screw on the right adjusts the stitch position. Inside that forked end there is a nylon bush. I think that may be the secret to the silent running of this machine. 

Finally the shaft was freed by using a heatgun. It didn't need much heat to make the shaft move very easily. Now that the shaft could move without the dial, the dial setting was completely out of adjustment, so it took some time to find the correct setting, but finally the machine was sewing and zigzagging like a new one.