Outer tub material
Plastic outer tubs are superior to porcelain on steel outer tubs, they last much longer they do not stress crack. I have never seen that once on any machine, not just whirlpool.
Porcelain on steel tubs eventually rust, it’s the number one problem when people are trying to restore old belt drive whirlpool washers it’s becoming one of the big problems for people that are restoring Maytag dependable care washers, you have a plastic tub in 50+ Years it will be in fine shape.
There is no difference in the possibility of mold or mineral buildup between plastic and porcelain outer tubs In fact, plastic tubs are much easier to clean and don’t seem to get the hard cement like buildup that you get on a porcelain on steel outer.
Washing machines with hanging suspension starting with the 1949 Whirlpool Belt Dr. machines on have always had a much more rigid cabinet because the cabinet supports the weight of the tub, etc. it just makes for a superior machine as far as staying rigid and staying in place compared to multi piece cabinet designs That can rattle and get flexed out of shape.
99% of automatic washers sold for residential use worldwide have a plastic outer town. It’s one of the least frequent problems, now if you want to talk about making it out of real stainless steel that’s another issue. The only residential washing machine available with a stainless steel outer tub is a Speed Queen front loader in the United States.
We have replaced far more porcelain on steel outer tubs in Speed Queen top load washers then we have replaced plastic outer tubs and all of the over 100 million built whirlpool top load washers over the past 40 years, I will say it’s nice that Speed Queen has a lifetime warranty on the outer tub But you may have to jump through hoops to get a free tub out of them, especially when the machine is older.
John