Mobil Polyrex EM Vs. Redline CV2 in wheel bearing

[Miatarcr]

I have a Miata that I track a couple dozen times a year. The problem I am having is that the bearings just arent lasting. I have gone through 2 sets in the front and 4 in the back and is ready for another set in the back. I did some research and it turns out that I am not the only one having problems, and they suggest removing the factory grease and repacking, even though it is supposed to be sealed for life, to approx 30% full. The brand of bearing I will be doing this to is F.A.G.

I would like to try this on the new set and would like to know if Mobil Polyrex EM, Mobil Polyrex EM 103 (thicker) or Redline CV2 would be the best choice for this and give longer life?

 

[Kestas]

There are many failure modes for a bearing. Has anyone looked at the bearings to determine how they failed? It is rare that wheel bearings would need a grease any more special than what they came with, unless the grease was turning black.

The number one reason for bearing failure is either misapplication or faulty installation.

 

[Tempest]

You'd be hard pressed to find someone that knows more about bearings than Kestas, so definitely heed what he is telling you.

If I were to do what you are looking to do, it would be with Amsoil 2000 Racing.

 

[Miatarcr]

I showed them to a couple of people and they commented on how little grease there was in them. They were the ones that suggested repacking them. As far as install issues- no I am 100% sure that they were done correctly- so the problem isnt that. It is tracking the car and the forces the bearings are seeing that is causeing the problems.

I looked at the Amsoil 2000 for a minute but the others I mentioned earlier seemed to be better. Is there anything special about the Amsoil grease that makes it better than the Mobil or Redline grease?

 

[Tempest]

Quote:
Is there anything special about the Amsoil grease that makes it better than the Mobil or Redline grease?

Only that many people here have used it with good results and that it is readily available. The Mobil Polyrex EM appears to also be a superb grease. Can you get it in small quantities?

 

[Kestas]

If the bearing is failing from excessive forces, the bearing may benefit from a higher viscosity grease if the failure is from surface spalling. If it's subsurface spalling, the grease choice is a moot point.

Excessive forces can also force a bearing to run in truncation. At that point the capacity of the bearing is exceeded, hence my comment on misapplication.

That's why a good failure analysis is helpful to understand what the problem is. With any failue, be it bearings, gears or anything, I tell my clients to first find the root cause of failure, instead of throwing solutions at a problem.

 

[Miatarcr]

Yes I can get the Polyrex EM for a really good price, $5.23 for a 14 oz tube with free shipping.
Drillspot.com
Originally Posted By: Tempest
Quote:

Only that many people here have used it with good results and that it is readily available. The Mobil Polyrex EM appears to also be a superb grease. Can you get it in small quantities?

 

[Miatarcr]

Thats is true kestas, I really just dont know. At this point I am going to guess that ball bearings were not a wise choice for this application, but Mazda just thought that they would just go with them. I think a roller type bearing would be the best choice for any wheel bearing, but that is just me. I hink the best way to deal with the issue for now is find a better grease.
In doing more research on the net it appears that some Subarus are having the same problem- and some in that crowd have gone to repacking with CV2, but I couldnt find info on the results- just that they did it.

There was also mention of the EP greases being a no no for bearings with nylon cages- something about the reaction between the sulpher in the grease reacting with Nylon. Do you know anything about this Kestas?

 

[tom slick]

Why a polyurea grease? That is usually spec'd for electric motors and high-speed bearings. Wheel bearings are not "high speed".

 

[Miatarcr]

I had read where some people were using it in motorcycle bearings, and some mentioned that it may be factory fill on some bearings. Besides that, the specs looked good to me, and with it being polyurea it offers some water resistance.

 

[Gillsy]

Originally Posted By: tom slick
Why a polyurea grease? That is usually spec'd for electric motors and high-speed bearings. Wheel bearings are not "high speed".

I was about to buy some polyurea once, but called a Chevron lube tech first. I'm glad I did. Although the polyurea had excellent specs it is not compatible with conventional greases. He stated that polyurea greases were often used in "sealed for life" applications.

 

[Miatarcr]

I have just finished cleaning the grease out of the new bearings. I flooded them with mineral spirits in a bowl and it took the grease right out. Its a good thing I did this as I found a surprising amount of fine grit that had come out of the bearing.
I am leaning towards the CV2 for the grease, many more people have used it to repack bearings with, and I think it may be even more waterproof than the Polyrex.

 

[mongo161]

You can always go with Valvoline DuraBlend Grease. It's on a clearance special at Amazon for about $2 for a 1 LB tub.

IMO....the best bang for your buck if you are cleaning out all of the old grease and want to replace it with a Synthetic Blend.

 

[tdi-rick]

Originally Posted By: Miatarcr

[snip]
I am leaning towards the CV2 for the grease, many more people have used it to repack bearings with, and I think it may be even more waterproof than the Polyrex.


CV2 uses a Calcium Sulfonate base, you won't get any more water resistant than that

 

[tom slick]

Originally Posted By: Gillsy
Originally Posted By: tom slick
Why a polyurea grease? That is usually spec'd for electric motors and high-speed bearings. Wheel bearings are not "high speed".

I was about to buy some polyurea once, but called a Chevron lube tech first. I'm glad I did. Although the polyurea had excellent specs it is not compatible with conventional greases. He stated that polyurea greases were often used in "sealed for life" applications.


I had the same conversation with Chevron tech support about their SRI (polyurea) grease. They have a list of compatible greases but it is short. They did not recommend it for the application it was being used in (similar to wheel bearings).

 

[Ben99GT]

Originally Posted By: Miatarcr
I am leaning towards the CV2 for the grease, many more people have used it to repack bearings with, and I think it may be even more waterproof than the Polyrex.


I've been using CV-2 in pretty much everything (including wheel bearings) for years now, experienced zero issues and I have been highly impressed.