Grease incompatibility: from metal base or other?

[Elkins45]

I have read for years that you need to clean out all of the existing grease before adding new in case the new grease is incompatible. It even says that on the grease container. I would like to know if that incompatibility is due to the metal base of the grease or if it’s because of certain additives?

So let’s say my tractor came from the factory lubricated with a lithium grease. Would I be OK using any other lithium based grease? There’s really no way to know which particular product was used and I don’t want to go running to the Kabota dealer every time I need a tube of (overpriced) grease.

My main concern is with trailer bearings. Is there a way to test if the grease in my gun is compatible with the grease that’s already in the bearings, or do I just have to bite the bullet and pull down the hubs of my new used trailer and repack them?

 

[salesrep]

Grease incompatibility is dependent on the thickener.

 

[Elkins45]

I suppose there's no easy way to determine what kind of grease is already there?

 

[RDMgr]

Incompatibility can be based on thickeners, additives and base oils. The ASTM method for determining compatibility of binary grease systems looks at both thickener and chemical compatibility. Thickener incompatibility usually results in consistency changes beyond the range established by the performance of the neat greases. Chemical compatibility usually results in loss of performance such as corrosion protection, EP or anti-wear.

As far as what kind of grease is used for factory fill, go on their website and try to find a PDS or SDS. This may give you a type but it won't give you compatibility with other commercial greases

 

[Silk]

For wheel bearings it's standard practice to strip, clean and repack. For bushes and any other greaseable point, you just squirt in what's in your gun.

 

[Elkins45]

Originally Posted By: Silk
For wheel bearings it's standard practice to strip, clean and repack. For bushes and any other greaseable point, you just squirt in what's in your gun.


I ended up pulling the hub and cleaning it out. Now I’m off to the parts store for new seals.