Hi Larry,

You describe the drive unit as sealed, then say it is a Whitlock. Is this hydraulic steering with an auxiliary AP pump or the typical RM electromechanic linear drive on a quadrant? Either way, it is possible the AP motor brushes are either bad or there is a lot of carbon in the brush holder area.

How old is the drive unit? I haven't seen one with a motor that was sealed and inaccessible. I have also seen the RM linear drive motor magnets come unglued with similar results as you see.

I have instructions and pictures of the disassembly of a RM linear drive, as well as a schematic if that is helpful.

Mark