When a 803A walks, you need to check the "Rubber Baby Buggy Bouncers, (vibration mounts) to see if they are cracked or broken. I once found a totally un repairable, (at our level of maintenance) 803A that had broken 3 of 4 vibration mounts. The movement of the fan caused the engine to shift to the right. The engine wound up on the battery, more or less. The vibrations of the still running engine, wore a hole in the Optima Red Top battery. At some point in time, the engine came into contact to the guts of the battery, with the predictable results. Arc welding 101.
One other reason the 803A walks is when the main gen is not mounted to the Engine coupling plate.