Reply to Sasquatch:
I called a local oil distributor close to me, they got me Shell "00" grease in five gallon pails, around $65 each. If you can find a business that specializes in oils close to you they may be able to help you out.
The usual button head fitting is a little larger than 3/4" across the flat top and is the "giant button head" size. The" standard button head" fittings are about 5/8 in diameter.
Without the relief valve in the line to prevent over pressurizing the seals in the rollers, you will be better off with a pistol grip gun, so you can feel when it gets tight before it blows the seals. You'll soon look like PopEye the sailor man though. If you are going to do this very often, you will want a high volume/low pressure bucket pump with a pressure relief on it. Be prepared for sticker shock though. An old CAT pump begins to look pretty attractive sometimes when you compare to a new industrial model from Alemite etc.
Most any petroleum jobber (Chevron, Texaco, etc. should be able to fix you up with grease. JD or other machinery dealer is convenient for some folks because they usually keep the 00 corn head grease in tubes for their agricultural customers. They probably can also order it in 5 gallon size buckets or might even stock it in an area with lots of corn. I have only ever bought it in the tubes though. Tube grease is always more expensive than bucket grease, so you can factor some of the savings in grease to go into purchasing a pump and save your forearm muscles too.
Someone usually warns against using EP grease and gear lube in old CATs. I don't think this is a real issue any longer since the concern was that the EP additive package would attack the brass and bronze bushings in the component being lubricated. The manufacturers have found additive packages that do not degrade the brass. I know the JD corn head gear boxes that use the grease they sell have bronze bushings in them, so it's made to be used in contact with that kind of metal.
D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time😄