I thought I would share an interesting conversation I had with one of the crew of the former Southern Pacific steam locomotive 4449's crew. The 4449 is a large mainline passenger steam locomotive built in 1941 for the Southern Pacific's Daylight passenger service and operated from 1941 to 1956 in regular service. It has been in occasional excursion service since being restored for the American Freedom Train in 1975. Lately the crew had noticed that first one, then two of the four main drive wheel bearings were getting hot. They proceeded to swap out the bearings on the wheels and found that they still were getting hotter than they should. They checked type of lubrication they were using and it was the same as always. After racking their brains and much consultations with experts in the field of lubrication and steam engines, they decided to ask the manufacturer if the formula for the lub had been changed recently. The manufacturer replied that they had stopped using some additive because "the only people that need that additive used it on steam locomotives, and no one ran steam locomotives anymore". They now have a special mix just for their locomotive and it runs fine again.
I was reminded of this story by the discussion of the drum brake shoe material being harder than the old stuff on some replacement shoes. Also our cars may or may not need a zinc additive for the crankcase oil.
Just because the number is the same as we used to use doesn't mean it is the right stuff necessarily. I really appreciate the experiences related here and at meetings with fellow Kaiser-Frazer-Willys enthusiasts as this can save valuable time and of course money.
