Ways to determine grease compatability

tractchores · Jun 14, 2018

I have a trailer that is new to me and I want to add some grease to the bearings. I have no idea what type of grease is in there already. Is there a way to tell if the grease is compatible by mixing some of it with the new grease or any other methods when one type is unknown? Trying to avoid a repack as the bearings and existing grease are in good shape, I just want to add some.

Einthewoods · Jun 14, 2018

This likely won't be helpful, and I'll probably get stomped on by some PhD wheel bearing grease expert.... :laughing:

I wouldn't give it any thought and use whatever wheel bearing grease you have on hand.

Beltzington · Jun 14, 2018

I don't have and answer but like most of us I do have an opinion

Ask the previous owner, if they don't know you likely need to start fresh anyway. Even with similar base greases the manufacturer is hesitant to guaranty compatibility with other brands, you see words like "most compatible" etc. they all recommend starting with clean hub when changing brands. I'll play devils advocate, what are you going to do if you can figure out what is currently in it? Buy a second grease gun for one trailer? I hate messing with grease guns and tubes and I have an expensive Milwaukee powered model.

I'm assuming the hubs have a grease fitting and you will be pushing the old grease out. If this is the case I agree with Einthewoods keep adding grease until the color remains consistent and don't worry about it.

Tractor Seabee · Jun 14, 2018

Wheel hubs are not a good place to mix grease; especially if the existing is an unkown. Take apart, clean up and re-pack with the proper lubricant for the application. Ball and roller bearings are also vunerable the mixe grease. Metal to metal surfaces not so much. Definately don't mixed cley base greases with others. They also tend to harden with age and plug up the passages.

Ron

Mace Canute · Jun 15, 2018

Tractor Seabee said:
Wheel hubs are not a good place to mix grease; especially if the existing is an unkown. Take apart, clean up and re-pack with the proper lubricant for the application. Ball and roller bearings are also vunerable the mixe grease. Metal to metal surfaces not so much. Definately don't mixed cley base greases with others. They also tend to harden with age and plug up the passages.

Ron

This is very good advice. :thumbsup:

tractchores · Jun 15, 2018

Figuring I probably just have to repack these... no way to contact the guy I bought it from. I was hoping I could scoop some grease out and mix it with the new stuff and see what happened.

yomax4 · Jun 16, 2018

I have to do the same with a new one I just bought. Sucks for sure but piece of mind is king out on the highway.

Fallon · Jun 16, 2018

How to Understand Grease Compatibility

Pile of other similar charts out there. But that isnt super helpful if you dont know what's already in there. Lithium complex is the least likely to cause any interaction problems.

sixdogs · Jun 16, 2018

It's unfortunate but you have to start over and clean the bearings and old grease and start with what you know. That's what I've always done. You could have the old string grease or who knows what. I've found dried out grease lots of times and to just grease over that wouldn't have worked.

kenlip · Jun 17, 2018

Fallon said:
How to Understand Grease Compatibility

Pile of other similar charts out there. But that isnt super helpful if you dont know what's already in there. Lithium complex is the least likely to cause any interaction problems.

Even the charts can't be relied on with confidence.

How to Determine Grease Compatibility and Why It's Important - Machinery Lubrication India

kenlip · Jun 17, 2018

Another factor, besides compatibility seems to be cleanliness.

Why Grease Cleanliness Should Not Be Overlooked

Besides the contaminants in the grease itself, it makes one think we should be paying a lot of attention to how clean the Zerks are when we are greasing our equipment.

Beltzington · Jun 17, 2018

Has anyone had a bearing fail conclusively to mixing grease? The couple I have had seized up where do to water in the bearing AKA not enough grease. There is another thread on TBN "don't mix grease" with good information including real world comments, "better to mix grease, than not have enough." Understandably the manufacturing world stresses bearings to the limit but I am not sure a 7-ton trailer and load even comes close to requiring this level of attention. If you file a flight plan with way-points and departure and arrival times when you drive to the market than carry-on otherwise I think we are being a tad pedant.

sixdogs · Jun 17, 2018

Beltzington said:
Has anyone had a bearing fail conclusively to mixing grease? The couple I have had seized up where do to water in the bearing AKA not enough grease. There is another thread on TBN "don't mix grease" with good information including real world comments, "better to mix grease, than not have enough." Understandably the manufacturing world stresses bearings to the limit but I am not sure a 7-ton trailer and load even comes close to requiring this level of attention. If you file a flight plan with way-points and departure and arrival times when you drive to the market than carry-on otherwise I think we are being a tad pedant.

I have repacked and replaced many haywagon and trailer bearings over the years and have seen many instances where one grease hardens up and nearly fills the voids around the bearings. There was additional grease added in many of these and it had nowhere to go since the other grease was hard. Some bearings and races were bad in nearly every case and the cause was lack of lubrication even though there was hardened lube and other grease in there.

The problem may or may not have been from grease compatibility but the age and hardening of the one grease didn't allow for the other grease to get in there to lube. If they were compatible they would have blended together? Just my observation here.

kenlip · Jun 17, 2018

Beltzington said:
There is another thread on TBN "don't mix grease"

How does one search for a thread with a specific string of words in the title? When I enter "don't mix grease" in the search and select the <search titles only> option, I get 1,567 hits.

Beltzington · Jun 17, 2018

sixdogs - would like to hear how you got that moniker.

I agree in a perfect world cleaning and repacking works and should be done if needed, I do disagree with recommendations that you must repack or you will spin a bearing. I am just curious if this is a real or TMI problem.

Beltzington · Jun 17, 2018

kenlip said:
How does one search for a thread with a specific string of words in the title? When I enter "don't mix grease" in the search and select the <search titles only> option, I get 1,567 hits.

I found it with a search engine.

http://www.tractorbynet.com/forums/oil-fuel-lubricants/157189-dont-mix-grease.html

Beltzington · Jun 17, 2018

kenlip said:
How does one search for a thread with a specific string of words in the title? When I enter "don't mix grease" in the search and select the <search titles only> option, I get 1,567 hits.

You are correct, I just tried it and it seems title searches are lacking. We could complain to the website owner but my creed is beggars should not be whinners.