Basically asking, how often were solid-bearings repacked and the date repainted on the car-side, data-markings?
Before 1929 Rule 66 stated that journals should be repacked as necessary. March 1, 1929 The ARA's Arbitration Committee revised Rule 66 and required cars in interchange be repacked every twelve months.
In 1933 the interval was increased to fifteen months. In 1955 the interval was increased to eighteen months. Beginning in 1958 if cars were equipped with specified journal lubricating devices the interval was twenty-four months, otherwise eighteen months through 1960.
