Most of the old crawlers i am aware of used the button head fittings and the rollers called for oil instead of grease. This is fine if all of the seals sre in good shape. I suppose the idea was that oil turned easier in cold weather? Someone may want to correct me on this, but I simply put grease in all of the rollers on my crawler and most people I know do the same. My memories of crawlers of old was that nearly every one of the danged things ALWAYS had a roller or two with shot bearings because the seals had failed and the oil had leaked out. My father quit using oil in the rollers many, many moons ago and switched to grease. I recently rebuilt Pop's old OC-4 and the only bearings on the unit that WEREN'T shot were the roller bearings. 

When you refer to the &quot;arms&quot; are you refering to the loader arms or something else? 

If you do want to stick with oil in the roller bearings Zimmermans in PA. was advertising a while back that they had the guns for injecting oil into roller bearings, I believe. See the LINKs section of this website.

Tractor Supply has 10, 20 and 30 wt. non-detergent oil on the shelf and most any place that sells oil can get it if they don't have it. If your seals are leaking but not completely shot 90wt or 140 wt. gear oil would work a lot better than the lighter stuff.