What the hell is going on with this grease?

Some sulfur containing EP additives are not compatible with copper bearing alloys. It's a common concern with gear oils. I've never heard of an issue with grease, but if the grease was made from oil with non-compatible additives...

This reminds me of a warning in a repair manual for old Jaguars, at least the early, 6-cyl. E-type: They had bronze ring gears and they had a note about which lubricants were compatible and incompatible.

My '57 Alfa Romeo Guilietta had a bronze distributor drive gear. I don't remember any specific warnings, but they were explicit about oil grades, including all of the letter designations that came after the weight.

(In '58, Alfa switched to steel gears.)

Worm gears tend to run hot, more so than the your roller bearings. It might be getting warmer in there than you think it is (shrug).

This web site has several articles on lube and worm gears:

Oil seems to be preferred over grease...

Greetings Ned, I tried to find out what kind of oil is used in the white grease I have and have had no luck. But I'm thinking you must be correct about the sulfur, even though the grease is not described as having any EP additives. Based on your post I am going to make sure that any greases I use in the future on bronze mechanisms do not contain sulfur or any other additives that can harm bronze. The grease in contact not only became a substance similar to thick glue parts of it turned into almost a solid. And conventional solvents used to dissolve greases had no effect I could see on the morphed grease when I cleaned it all out. Eric

"Sulfurized mineral oil will readily stain copper under the conditions of the Copper Corrosion Test (ASTM D130), which uses a copper test

indication of chemical reactivity to yellow metals."

Also search for the Copper Mirror test.

-jsw

[ ... ]

Hmm ... perhaps it forms a sulfuric acid under pressure and load?

Can you try some PH paper on the remains to see whether it is somewhat acidic?

Hmm .... what about Molybdnium DiSulfide grease? I suspect that it would work well with copper-bearing metals such as the worm gear. (Unless someone else knows differently.) At least check with the makers to see whether they know of any such problems.

Good Luck, DoN.

Anything with sulphur or chlorine will attack bronze..

I think I'd be looking at something like SKIL 80111 heavy duty worm gear saw lubricant - made expressly for bronze gears and extreme high pressure. 8 ounces is about $12. I bough a tube for my old 825. It is technically an oil, not a grease. Personally I have very little use for the typical white lithium grease,(like LubriPlate)

Damn, not cool. They actually sell bronze sink fixtures, too.

I've already reassembled the dividing head with some other grease that doesn't have any EP additives, I needed it to finish a job. But I am going to look into bronze worm gear specific greases because I have two other devices with some bronze gearing. That Skil 8011 stuff, does it stick like gease? Is it as thick as grease? The dividing head doesn't have a sealed reservoir, the grease just sticks to the works and doesn't drip off. Eric

No, it's closer in consistency to EP140 Hypoid oil

Ye gods, I'd rather smell rotting fish than hypoid gear lube. Hate that stench.