I need some fundamentals on steam engine drive wheel and linkage alignment.  The right side drive wheel is off the motor shaft at the moment.  The left side drive wheel will fully rotate from the motor, but the linkage only allows the two front wheels to oscillate back and forth.  With the rear wheel linkage removed the front two wheel will full rotate from each other.  I was wondering if the linkage is worn from the rear drive wheel not allowing the full rotation of the front two wheels?

When I get that solved, and when pressing the right side drive wheel on the motor shaft, is there a need for the linkage to be offset from that of the left side?  I need some basics on how the linkage works between the drive wheels on a steam engine.

Dave
Nebraska City