Yellow Metal in a transmission or differential

Posted by scott12180 On 2017/7/20 9:31:40

I have a 1932 902 standard eight.

Is there yellow metal in the transmission or differential?

Brass and bronze are not compatible with gear oils rated GL-5 due to the high sulpher content, so I understand. But I don't know what's inside a Packard transmission or rear end of this vintage. Can I use a modern GL-5 or should I look for a GL-4 or other low-tech gear oil?

Thanks -- Scott

Troy, NY