[M2M]

Originally Posted by Purdy Swoft

They say that the W stands for winter . I've been told that the so called 600 W gear oil that is sold by the model A parts vendors is made up from a mixture of 140W and STP . A person can mix and make their own gear oil . I have used 90 W with no problem if I didn't have any 600W and it shifted just fine .

W does stand for winter in multigrade oils...the W in 600W I don't think means that as it dates back to the 1920s when multigrade oil didn't exist. Today 600W is a marketing name, nothing more.

I prefer a heavier oil than 140 but if you okay with it I'd go for something like this and avoid the dirty tricks of the suppliers and save $:

https://www.amazon.com/Sta-Lube-SL24...f_B000M8IHI2/?