Rear end Gear lube

[Eman]

Originally Posted by Rory McNeil

I`m curious as well. I had been told that the main difference between GL-4 and GL-5 gear oils, was that the GL-4 was designed for use in manual transmissions with "yellow metal" syncronizers, like brass/bronze, and the GL-5 was for syncros with paper or carbon fiber linings. It seems that finding GL-4 gear oil is not as easy these days, GL-5 seems far more common. For the Toploader 4 speed in my street car, I have been using GL-4 Brad Penn, seems most of the major oil companies have just GL-5.

I've got some Ford gear oil F2ZZ-19C547-A which should be GL-4 80W Ford parts oil Ford spec. M2C83-C. I've got 4 or 5 quarts I'd sell.