I have a '51 GMC 620 with an Eaton 2-speed vacuum shift. The code on the axle says S-7544, which is not specified in my manual for this truck.

In any case, I'm wondering if there is an electric shifter to replace the diaphragm which pulls on a crank which shifts the unit. I no longer have the air shift control valve that controls this thing, so I'm stuck in low range.

Thanks for the help.

Day Radebaugh