Has anyone used Amsoil synthetic Transmission lube 75W-90 GL-4 in their 1969 4 speed?
...faulty lubes are pretty much non-existant.
There is some pretty low grade stuff on the dollar store shelves and places like that which can over-extended in many applications pretty quickly. But I doubt they are claiming any warranty support either, so caveat emptor.
The biggest contributor to lube-related failure is and always has been the "luber," i.e. the person pouring in the oil. Wrong oil for the application, excessively long service interval, low fluid levels caused by leaks / not regularly checking, all contribute to this problem.
These tools of ignorance are regularly wielded by creatively stupid self-appointed home mechanics to kill automotive equipment all the time. That is why lube warranties are patently absurd, by definition.
Keep up the good work Amsoil. Love your oil, just not willing to pay the premium price for a worthless warranty.