Looking for a clarification since manual a bit unclear - want to remove the rear casing (4 speed) to replace the gasket. Does something have to be done to the speedo first to ensure no damage to gear?
No, the tail shaft housing will slip right off the out put shaft were there is a nice large plastic gear which drives the speedo cable housings gear and shaft which is screwed to the housing.
As long as that small housing which the cable attaches to is not frozen up it will spin and allow the plastic gear to move the shaft as the tail shaft housing is pulled away from the center cast iron section of the transmission.
