Frozen camshaft on Sawsmith yoke handle

[Jkazak54]

I recently acquired a Sawsmith RAS. The only problem is that the knob on the yoke handle would not move, period. Drove out the pin, shaft still would not move. I have tried PB blaster for over five days, shaft will not turn nor be driven up or down. What in the world could cause this shaft to seize this badly? Any help would be greatly appreciated, and the sooner the better, because the rest of the saw is in great shape.

[JPG]

I am not familiar with the RAS, but a steel shaft in an aluminum casting can get severely stuck due to galvanic 'stuff'.

The most highly recommended penetrating fluid seems to be a mixture of ATF (F=fluid) and acetone(50-50 IIRC).

Heat to the casting might help.

If the shaft was pinned, torque to the hole may help if the shaft is round.