Disassembly and maintenance of the Big Boy

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Shell removal

Valve Hanger and Piston guide interference.

Front driver removal

Removal of the bottom plate

Exposed journals and drive gearing.

Drivers can be removed as an assembly

Motor Removal

Drive coupling details

Valve hanger and piston rods can be removed as an assembly

To access drive gears remove these scrwes.
Do not loose the insulators and insulator pin at rear hole .

The worm gear can now be pressed out if needed

Tie wraps added to help control the wiring at rear truck.