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Are my bearings supposed to sling grease?

jcarne

Well Known Member
Patron
Hello everyone, my right main wheel throws a fair amount of grease and I'm wondering is this normal? My left throws some but not nearly as much.

I will try and get to the hangar later to get a much better picture but you can see in this one the black area. It's not so much grease that it makes it onto the tire but there is definitely a fair amount on the rim all the way around the perimeter.

Thanks in advance!
 

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That grease looks black, do you have Cleveland wheels?

OK - I don't know what you have specifically for bearings and seals, but the Clevelands use a felt or rubber seal and red Mobil SHC-100 grease. The only way that grease will sling out is it has a low viscosity and a poor seal for the outside diameter of the seal.

Here is a post where I tested sling out of my Cleveland felt seals lubed with motor oil. The test was specifically for this reason.
https://vansairforce.net/community/showpost.php?p=1515934&postcount=9
 
That grease looks black, do you have Cleveland wheels?

OK - I don't know what you have specifically for bearings and seals, but the Clevelands use a felt or rubber seal and red Mobil SHC-100 grease. The only way that grease will sling out is it has a low viscosity and a poor seal for the outside diameter of the seal.

Here is a post where I tested sling out of my Cleveland felt seals lubed with motor oil. The test was specifically for this reason.
https://vansairforce.net/community/showpost.php?p=1515934&postcount=9

Negative on the Clevelands. I am using the stock Matcos. They don't have a felt seal but have a rubber seal/ dust cover. I'll try and get a close up picture of the seal as well. As far as grease I used Aeroshell #5 as per the Van's manual.
 
I think it's fairly common Jereme. It'll become less once the amount of grease in the wheel hits a sweet spot. During my annual I chose not to add more because the grease still looked new and everthing was still coated really well, It's fairly common for some greases to separate somewhat also.
 
Is it possible . . .

Having just packed my wheels in the last 4 days, I wonder if the cavity of air between the bearings is pressurizing when it gets hot for the first time, and the bearings were freshly packed to completely seal the bearing to air passage. Then, at some point, it pushes the grease out past the seal.

Have I missed where the hot air might vent? The tube seals the split gap, and the tight grommet seals the cavity.

The felt seal is a little different, if the bearings are packed and grease sealed to air, the felt seal is porous and can accept some grease of it expands out from the bearing.

The rubber seal could seal the OD nicely, and it could be packed solid with grease, in that case the grease would have no place to expand except past the seal.
 
Having just packed my wheels in the last 4 days, I wonder if the cavity of air between the bearings is pressurizing when it gets hot for the first time, and the bearings were freshly packed to completely seal the bearing to air passage. Then, at some point, it pushes the grease out past the seal.

Have I missed where the hot air might vent? The tube seals the split gap, and the tight grommet seals the cavity.

The felt seal is a little different, if the bearings are packed and grease sealed to air, the felt seal is porous and can accept some grease of it expands out from the bearing.

The rubber seal could seal the OD nicely, and it could be packed solid with grease, in that case the grease would have no place to expand except past the seal.

Ya I am wondering that is what's going on. Grease has to go somewhere.
 
What you are seeing is "normal", but it would imply two things: 1.) you need a differntt grease - Try Red Line Tacky. 2.) you are packing too much grease into the cavity.
 
Four out of the five RV’s I’ve owned have had Cleveland wheels and brakes. The last one I built (RV8), had Matco’s. I was surprised at the installation difference between the two. With Cleveland’s, you would tighten the axle nut while spinning the tire and tighten to just where the tire stopped spinning, then back off and do it a couple more times until any slack was gone. You would drill for the pin at the point just before the tire quit spinning. On the Matco, you would follow the same procedure, except when you got to the point where the tire just barely stopped spinning, you would then go one flat on the axle nut tighter, and then drill your hole. The important thing was that the black bearing seal wouldn’t spin at all during use. I don’t know if they still install that same way, or if this is pertinent to the issue you are experiencing, but I thought it was odd that there was this difference.
 
Thanks for the replies guys. I'll keep an eye on it and likely switch to a different grease on my next annual. Van's specs Aeroshell 5 in the manual but the manual from Matco does not. I'll try something in line with the Matco manual next.
 
Four out of the five RV’s I’ve owned have had Cleveland wheels and brakes. The last one I built (RV8), had Matco’s. I was surprised at the installation difference between the two. With Cleveland’s, you would tighten the axle nut while spinning the tire and tighten to just where the tire stopped spinning, then back off and do it a couple more times until any slack was gone. You would drill for the pin at the point just before the tire quit spinning. On the Matco, you would follow the same procedure, except when you got to the point where the tire just barely stopped spinning, you would then go one flat on the axle nut tighter, and then drill your hole. The important thing was that the black bearing seal wouldn’t spin at all during use. I don’t know if they still install that same way, or if this is pertinent to the issue you are experiencing, but I thought it was odd that there was this difference.

The slipping and rotation of the inner race and/or the spacer used as an inner contact for the seal happens on my Cleveland. I have been aware of taper roller bearing installations and know of one critical application where there was no preload. The idea was at temperature the bearings would load and take up the "gap".
I do wonder about the bearing manufacturer's recommendation. If a contacting lip seal replaces the Cleveland felt the additional friction drag will aggravate the rotation of the (seal) spacers. At only 150 hrs, and all 4 of my spacers showed indication of rotation (felt seal). If Timken requires end play, then the only (design) recourse is an internal contact sleeve to allow torquing of the axle nut to capture the spacers and inner races.
 
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