The first real job I had back in the late 50's was in a Chevrolet dealership and I started out as a greaser. Standard oil for the trans, rear end and steering gear was simply gear oil. After that I worked in as a parts man for another five years and that was all that I ever saw used in steering gears.
No reason why it should break down in a lightly used area like a steering gear when it doesn't break down in a trans of differential. As far as the Penrite goes It's probably just a gear oil packaged so you will feel like your using the "correct" lubricant in your vintage steering gear.
And I hold to my statement, if your loosing gear oil from your steering box then you have a worn seal, worn sealing surface on the sector and or loose bushings. Repair those and you won't have leaks.
DG
