Hi Crenwelge. This subject is very interesting to me because I have always found trensmission function facinating. I don't know if you have ever looked into a motorcycle transmission, but they have a completely different way of synchronizing gears, using dowels called "dogs" that protrude from gears that slide and engage into slots in gears that don't slide.
Anyway, back to MT-1. It is my understanding that MT-1 designates GL-5 lubes that are safe for use with yellow metals. Do the big truck unsynchronized transmissions have yellow metals in them? If not, why would the transmission manufacturers specify MT-1?
How does the 50W that you use compare in viscosity to various gear oils?
I have a '71 Dodge van that I bought new and I have adapted a 4-speed New Process model 445 top loading trans into it to get improved gear ratios for towing. Chrysler specifies 50W motor oil for that trans and I found that viscosity in racing oil.
My Stovebolt is a '36 Chevy pickup that seems to shift best with so called "600 weight oil" that I get from The Filling Station. I understand that "600 weight oil" is similar in viscosity to 160 that is no longer available. Do you know if that is correct?
