So here we go again. Polyurea grease in MY area sold out ”indefinitely”.
No John Deere Green polyurea or Lucas green polyurea grease anywhere.
Checked everywhere, box stores, hardware stores, farm stores, tractor dealers. Nothing, zip, nada.
I have 2 automatic greasers I have to keep loaded with grease or Hay Dude makes no hay.
So the question is, what type of grease mixes with polyurea grease without clogging issues?
Things are getting desperate.
I don't know that answer. Polyurea is the thickener in the John Deere HD Polyurea Grease that carries the oil like a sponge carries water. And we've discussed before that Lucas Green seems to use the same chemistry as the JD Poly...so those two should be as interchangeable as greases get.
Just for some background so others can follow this grease problem :
Greases are basically oil soaked into a thickener like water into a sponge. Several substances are used as thickeners. Polyurea is a popular powder thickener because it is a reliable synthetic. Other greases use either a soap or a clay based thickener. Soaps and clays both are built around light metal molecules mostly of lithium, calcium, barium.
The oil used in the thickener is not the problem. All the oils are compatible. The problem is that when incompatible greases get together they harden and at the same time they expel their oil
This is because different thickeners are chemically reactive with each other. They don't corrode the bearing surface, but instead they can react to clump up, harden and cake. When they do, they take up space and while they do their clumping they dump their oil content. Basically if you use incompatible greases the bearing space becomes filled up with dirt and no room for oil. You can see it easy enough if you take the joint apart. You end up scraping out this dry crud. Usually the first clue you have to incompatibility is that the zerk seems to nbe jammed or stuck or shut or not accepting grease.
Hay Dude, I don't have an answer. JD SD Polyurea (and Lucas) advertise as being a new style shear stabilized poly urea - they used to be conventional but changed - and shear stable is way better than the old conventional poly....but I'd still stay away from calcium and lithium based greases anyway. Even the JD products.
Frankly I'd find the genuine JD/Lucas or skip a couple of lube cycles. Maybe rig up a zerk injector to pump in some 80/90 in critical joints until I could get some genuine. This sucks....
Some literature - some if a bit deep - is attached. The RP report is valuable because it compares different manufacturer's compatibility charts instead of comparing compatibility directly.
The other one is heavy on chemistry... read at your peril...
rScotty
