This gear box from Pacific Gear & Tool Works is installed on a vintage rubber mill and yes it is not yellow, but in reading about the mfg, it appears these gear boxes were installed on cranes derricks winches etc. Thusly, if the 'stretch of the request is being begged to be included herein', perhaps a recommendation for the lubricant? Present lubricant material is reasonably amber although doesnt have the heavy odor that a vehicle rear diff has. Keep in mind: No person says that it is correct LOL. I had it sampled & analyzed and the recommendation is to change it. Have also attached some pics of said gearbox. Tis no small item as it is about 4 feet by 2 feet in plan view and about 2 feet tall. Input shaft on one end, and output shaft on the other end. Some searching for either of the mfg's names yielded this article: Pacific Gear & Tool Works, San Francisco, ca. 1907 www.historylink.org Article from History Link dot org The company Pacific Gear & Tool Works was combined w Western Gear in 1953, giving me hope of finding something to indicate the lubricant.... As an conversational aside on another gear box, we just goofed up and put a AGMA 4 in a gearbox that spec'd a AGMA 5 and it turned out the copper degradation test was a little different requirements. Although the viscosity was correct, other attributes unfortunately were a lesser compliant.
Maybe a idea of how fast the gearbox is turning and what kind of HP is going through the box? Also knowing what kind of bearings are in it might help.
That's a interesting link/story about Western Gear. Should read the full story about the Glomar Explore. I'm going to guess straight 50 wt. That's a guess.
Seems curious the sub fell apart during the lift and only one portion made it to the lifting ship - Blind Mans Bluff shows some pics and tells some tales.... As to the gearbox, the one attachment was the lab oil analysis and it showed high particle count; as to the as found viscosity at 100C was spot on for a 50W.