What "grease" are people using for their Duff-Norton air jacks? It seems it should be a semi liquid like an 00 grease or heavy oil like steam cylinder oil, rather then a solid grease no 2 or so. I have one of ours apart for cleaning and repairs and it is clear the old grease was not circulating well and starving the bearings for the air motor.

You could ask the Alaskan RR #557 folks as they went through a bunch of their D-N air jacks recently. Think they were in contact with Duff Norton during a lot of that work for parts and schematics? I am curious as to what you find.

http://www.557.alaskarails.org/restore/ ... Elmore.jpg

A few months ago I pulled an old mechanical Duff {hadn't merged with Norton yet?} jack out of the mud. It has been through a flood and was in a scrap pile. I might of gave up on it had I known it was so bad. Ended up froze solid and every moving part was corroded in place. Have unfroze everything but the transmission which now works but, gears/shaft are supposed to be independent until engaged. I will eventually win this battle but not sure why. I wanted to learn so that is why I went into this and it will work slick when done. We have enough air jacks on the property that I doubt anyone will ever use this one. Very interesting, incredible pc of machinery. Simple, robust and old fashioned technology at its best. Along with moisture there was old hard grease that wasn't going to be doing anything if it had been working. So I am interested in hearing what you find out. Pretty sure the jack I am working on is pretty much the same as an air jack minus the air motor. Best of luck to you and this endeavor. John

You have two different lubrication applications.
The first one is the grease that should be used on all load bearing parts such as the buttress thread and nut, gears, and bearings. I recommend an "EP" grease that maintains its properties over a large temperature range and is resistant to washout. I use Conoco Megaplex XD3. https://phillips66lubricants.com/produc ... rth-moving
The second lubrication application is the air motor. An air motor should never be used without a lubricator and a dirt stopper. The lubricator can be filled with any good quality air tool oil, even ATF works well. The most important fact is that the lubricator supply's a constant mist of oil to the air motor during operation. Also, you are constantly pushing oil, mixed in the air supply, through the air motor to help keep it clean. No air supply is 100% clean unless you use breathing grade oxygen or nitrogen to run your air motor. The next best thing is to constantly flush it with clean oil. If the air motor is very dirty you can pour #2 diesel in the supply hose, hook it up to your air source and run it. The exhaust will give you visual results of what's coming out. Repeat as needed. You won't hurt anything because #2 is an "oil".
I wouldn't get too hung up on the exact lubrication as long as you have lubrication. (I don't use Radio Shack batteries in my Radio Shack calculator. Please don't tell them !)
I also wouldn't take the air motor apart unless you have to. If it runs flush it with #2, get a lubricator and dirt stopper, and run it. The thing will probably run for the rest of your lifetime.

Thanks for the tip on lubercation. I can use your ideas on my mechanical as well as the air jacks at the museum. Regards, John.

I have put an oiler on the air line, and the air motor is in good condition. I have the jack cleaned up on the inside and back together with some minor repairs done. Thanks for the tips on grease. Will be using it this weekend.

I forgot to mention that the oiler has to be sized to pass the same CFM as the supply hose. I assume you are using 3/4" hose with Chicago fittings. Pressure X Volume = Horsepower. Also, you shouldn't "neck down" or reduce the diameter of any part of your air supply. Everything should be 3/4" from the tank or compressor to the jack.