Hi,
Yes, Corn Head grease works well. I'm still using stuff in a 5 gallon pail from back in the late 1940's / early 1950's which was meant for such service at the time these things were new.
Unfortunately, I have not found a suitable alternative at any of the area lubrication shops. You know, places that sell specialized lubricants and are usually associated with a tank farm.
It appears that the last lubricant company to market something for this application was Kendall, now long gone. My stuff was made by Socony-Vacuum Oil Co. and they're now known as Mobil, but modern-day Mobil has nothing like the old Gargoyle Number 10 grease.....
One of my best friends dad was VP of R&D for Kendall, then later Quaker State until he retired. He recalls that kind of lubricant, but knows of no outfit still catering to such uses. I've spent many an hour showing him older lubricants I still have kicking around and learning just what is in them so I can figure out something newer to use in place of the older stuff.
Most of the brands you see out there now, which you recognize as old American oil companies, are no longer anything but a brand name. Most are owned by the same holding company and so sell the same things even though their advertising would lead one to think they are different.
That leaves us pretty much with the equipment maker's offerings as they buy enough of whatever they carry to get the stuff made to their specs.
Unfortunately, Deere no longer offers a roller/idler lubricant. They do offer Corn Head grease which is as close a substitute as you are going to find. The stuff is somewhat thicker than what was originally used but is still runny enough to pump itself around inside the idlers and rollers.
What all the outfits sell these days for 140 weight is too runny as it's all really multigrade and a lot closer to 90 weight than 140 weight. At least I can't locate a source of straight-weight 140 or anything that says it's 140 and is actually anywhere near 140's viscosity.
The other problem is the gun one uses. You need a low pressure gun, and those haven't been made for about as long as the lubricants for rollers hasn't been. I have one, but only the one. The thing is that it has a lot of back pressure on the handle and so you can tell when it's time to stop pumping.
I use my low pressure gun with the Gargoyle lubricant as it's not a cartridge style gun. You have to pour the thick stuff in thru a cap. I use a pistol grip style gun with the Corn Head grease cartridges. I use my one finger on the end of the trigger to feel when it's time to stop pumping. However, you have to pay attention or it's easy to go too far and blow out a seal.
I use the old lube every other time I grease things, so my rollers have a mix of old and new in them all the time. This way the old grease will last probably until the end of my life. After which, I guess I don't care any longer what is used!
Later!
Stan