Ok, I finally did it and picked up the wrong grease gun and lubed the spindles of my JD 425 with Mystic Red. I usually use JD PolyUrea grease on everything on the tractor. Will it be a big deal or not? I was all over the net and it seems JD PU grease is compatible with a lot of grreases, so I'm assuming it's the shear stable PU and it won't matter but thought I'd get some opinions.
Mixed grease question
- Thread starter bchannell
- Start date
- Status
Here is a chart you should bookmark. It shows you what grease types are compatible with each other.
I believe Mystic Red is lithium complex, so mixing with PU is potentially bad.
https://www.machinerylubrication.com/Read/1865/grease-compatibility
I believe Mystic Red is lithium complex, so mixing with PU is potentially bad.
https://www.machinerylubrication.com/Read/1865/grease-compatibility
Reddy45, that chart shows 2 types of polyurea grease, with the shear stable type being compatible with almost all others. If you do a Google search like bchannell did, the interweb "experts" (sorry, LOL) tend to come to an unsubstantiated conclusion that the JD polyurea grease "probably" IS the shear stable type. I did not come up with any definitive evidence that anyone contacted JD corporate to confirm this. But, their literature that states "compatible with most greases" is somewhat convincing. Its hard to imagine they would market it AND install it at the factory if there was potential for expensive damage. bchannel, I think you are probably o.k., with no proof to support my opinion.
I don't understand why John Deere is pushing their polyurea grease so hard as the BEST. I almost think it is a marketing strategy to convince people to only buy their product (more profit, store visits, and customer loyalty for them). I.E., some people think that colored grease is better than amber grease. It seems that the initial applications for polyurea grease was for long life, sealed electric motor bearings and similar applications. The JD literature states that their lithium complex grease is almost as good as the polyurea. Beyond the thickener difference, I "think" they use similar types of mineral oil lubricant based on some vague JD literature. No synthetic oil mentioned. The polyurea has better washout properties (2% vs. 4% for the lithium complex). But, the polyurea grease has a quite low timken load of only 45 compared to 60 for the lithium complex. So, if you are using these greases for general purpose, do you want better washout or better EP protection? For me (my tractors are not exposed to washout), I think that better EP protection is a higher priority.
I'm not convinced that JD's polyurea grease is as great as they claim. IF I were to search out a higher quality, severe use grease (i'm not), I would probably consider Schaffers or Amsoil as a good start. I've been using the JD lithium complex for 25 years with no apparent problems, BUT, my applications are not severe duty and I do not neglect grease management. Just my 2 cents!
https://jdparts.deere.com/partsmkt/document/english/featbene/JDMGrease_training_52015.pdf
https://jdparts.deere.com/partsmkt/document/english/pmac/8180_fb_GreaseSpecialMultiPurpose.htm
I don't understand why John Deere is pushing their polyurea grease so hard as the BEST. I almost think it is a marketing strategy to convince people to only buy their product (more profit, store visits, and customer loyalty for them). I.E., some people think that colored grease is better than amber grease. It seems that the initial applications for polyurea grease was for long life, sealed electric motor bearings and similar applications. The JD literature states that their lithium complex grease is almost as good as the polyurea. Beyond the thickener difference, I "think" they use similar types of mineral oil lubricant based on some vague JD literature. No synthetic oil mentioned. The polyurea has better washout properties (2% vs. 4% for the lithium complex). But, the polyurea grease has a quite low timken load of only 45 compared to 60 for the lithium complex. So, if you are using these greases for general purpose, do you want better washout or better EP protection? For me (my tractors are not exposed to washout), I think that better EP protection is a higher priority.
I'm not convinced that JD's polyurea grease is as great as they claim. IF I were to search out a higher quality, severe use grease (i'm not), I would probably consider Schaffers or Amsoil as a good start. I've been using the JD lithium complex for 25 years with no apparent problems, BUT, my applications are not severe duty and I do not neglect grease management. Just my 2 cents!
https://jdparts.deere.com/partsmkt/document/english/featbene/JDMGrease_training_52015.pdf
https://jdparts.deere.com/partsmkt/document/english/pmac/8180_fb_GreaseSpecialMultiPurpose.htm
DIY - I agree. I doubt that JD's grease would be formulated so specifically as to be incompatible with lithium complex greases.
But yeah.. we don't know for certain.
Assuming it's easy to grease the zerks on these lawn tractors then I'd just switch over to lithium complex and then get in the habit of re-greasing every year. Eventually the old stuff will squeeze out.
But yeah.. we don't know for certain.
Assuming it's easy to grease the zerks on these lawn tractors then I'd just switch over to lithium complex and then get in the habit of re-greasing every year. Eventually the old stuff will squeeze out.
you know, I guess I just went with the common knowledge recommendation to use JD Polyurea, but after looking over the specs, it sure seems that the Mystic JT6 that I mistakenly used on the spindles is a far superior grease. I think you may be right that JD PU is nothing special when compared to other greases. I use JT6 on my truck and virtually everything else I use grease on. I just may switch the whole tractor over to JT6 and be done with it. I'm not saying the JD PU is inferior, as it probably does a decent job. I actually thought it would make sense that if the factory uses it, they would not be using a grease that is not compatible with the single most prevalent grease out there, which is Lithium complex. Also, I think I read a long time ago, but can't remember where, that someone did call JD tech support and asked this very question and was told mixing was fine, at least for these two types.
Well, you know what they say about opinions. My grease expertise doesn't go beyond my internet education and 40 years of anecdotal experience with non-severe ag. equipment (not a real qualifier). For instance, I really don't know if the difference between Timken OK Load 45 vs. 60 is significant for our applications. Bigger is not always better.
So, now you are contemplating moving away from JD polyurea and I am considering moving towards using it! My real opinion is that for my non severe conditions the lithium complex is plenty good enough and that I might only notice a performance difference with the polyurea IF I was operating under severe conditions and/or maybe neglecting lubrication. My analogy is that if regular strength aspirin knocks out the headache fine, extra strength is not going to be any better.
Below is some literature to contribute to analysis paralysis. The first one states about JD's best polyurea grease : " Used for initial lubrication at the factory in U-joints and axle bearings". Hmmmm, does that mean only in the u-joints and axle bearings? Next time I am at Deere, I will take a peak at the grease color in some of the zerk areas. The white paper below strengthens my perception that the JD polyurea grease is the compatible shear stable type and NOT the thixotropic type they mention their corn head grease is. Finally , I found the Mobil polyurea grease tech sheet interesting because they state that their excellent shear stability is "similar to the performance of high-quality lithium-complex greases, which are the benchmark for excellent shear stability."
https://jdparts.deere.com/partsmkt/document/english/pmac/8180_fb_GreaseSpecialMultiPurpose.htm
http://cdn2.hubspot.net/hubfs/515485/Noion_Technologies_June_2016_Files/Documents/WhitePaper-14.pdf
https://www.mobil.com/english-in/grease/pds/glxxmobil-polyrex-ep-2
Yea, Mystic high temp JT6 has impressive stats. http://docs.mystiklubes.com/msds_pi/M20026.pdf If I ever change brands, that would be my choice. Thanks for stirring up my grease OCD - NOT!
So, now you are contemplating moving away from JD polyurea and I am considering moving towards using it! My real opinion is that for my non severe conditions the lithium complex is plenty good enough and that I might only notice a performance difference with the polyurea IF I was operating under severe conditions and/or maybe neglecting lubrication. My analogy is that if regular strength aspirin knocks out the headache fine, extra strength is not going to be any better.
Below is some literature to contribute to analysis paralysis. The first one states about JD's best polyurea grease : " Used for initial lubrication at the factory in U-joints and axle bearings". Hmmmm, does that mean only in the u-joints and axle bearings? Next time I am at Deere, I will take a peak at the grease color in some of the zerk areas. The white paper below strengthens my perception that the JD polyurea grease is the compatible shear stable type and NOT the thixotropic type they mention their corn head grease is. Finally , I found the Mobil polyurea grease tech sheet interesting because they state that their excellent shear stability is "similar to the performance of high-quality lithium-complex greases, which are the benchmark for excellent shear stability."
https://jdparts.deere.com/partsmkt/document/english/pmac/8180_fb_GreaseSpecialMultiPurpose.htm
http://cdn2.hubspot.net/hubfs/515485/Noion_Technologies_June_2016_Files/Documents/WhitePaper-14.pdf
https://www.mobil.com/english-in/grease/pds/glxxmobil-polyrex-ep-2
Yea, Mystic high temp JT6 has impressive stats. http://docs.mystiklubes.com/msds_pi/M20026.pdf If I ever change brands, that would be my choice. Thanks for stirring up my grease OCD - NOT!
Just FYI, I emailed Mystic Lubricants and asked about the compatibility of the two greases. They were non committal, as i had expected, and said they didn't do any compatibility testing with JD PU, and recommended a full flush out. Safe, and of no value whatsoever, just as I expected.
- Status
