# Trailer bearing grease packing - are we packing the bearings? Or the hub?



## de-nagorg (Feb 23, 2014)

Grease packed into the hub will eventually solidify, and be very hard to remove later.

I have always just packed the bearing , fingered a little on the races, and reassembled. With a slight coating on the axle shaft.

You do know that there is a bearing packing tool where the bearing is clamped between two cups, and grease is pumped into a zerk on one cup.

filing the bearing.

MESSY.


I prefer to do it by hand, then wipe my hands. 



ED


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## jkeuning (Oct 28, 2011)

Yeah I've seen that bearing-packing tool. I prefer to do it by hand also.


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## SeniorSitizen (Sep 10, 2012)

Being the grease fitting is in the dust cap like on many boat trailers the seal is installed in reverse as a dirt/water seal so you can pump the hub full of grease without blowing the seal lip out as would be done if the seal is installed, the conventional way, to keep grease in.


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## Oso954 (Jun 23, 2012)

If you "have a grease fitting in the center of your dust cap" it sounds like you have Bearing buddy's. For most trailers that will eliminate the need to repack bearings. If it is a boat trailer, you should still tear them down for inspection every year or two. Then repack the bearing and pump up the bearing buddy after reinstallation.

If you are pumping them up until the grease comes out the seal, you are over filling them and damaging the seal. You only fill them until the piston moves out 1/8 inch or so. If you can press on the piston and it moves, there is enough grease. If it doesn't move, add grease until it moves outward about 1/8".

The Constant Spring pressure keeps dust, dirt, or water from entering the hub/bearing area. The exception is boat trailers here dunking the hot wheel in cold water can wash out some of the grease. It is best to let the hubs cool down a bit before attempting a boat launch.


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## Gary in WA (Mar 11, 2009)

Interesting... http://www.wakeworld.com/forum/showthread.php?t=782730

I've read numerous times that dust caps are just that and should not be packed to slow the cooling of a hot bearing...

Gary


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## SeniorSitizen (Sep 10, 2012)

Hot bearings. Just how hot is hot? A bearing gets too hot because of the mechanic having the castle nut too tight, period. And after packing he doesn't have enough knowledge to stop after a couple of miles and feel for abnormal temperature increase.


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## Gary in WA (Mar 11, 2009)

Lol, my definition of "hot" is different than your definition. Around here, 90*F is hot for me.... 120*F (or less- hopefully) for my trailer bearings (no brakes); http://www.boatus.com/magazine/trailering/2012/september/trailer-tire-bearings.asp Depends on where the zerk is also, mine is between bearings- closer to the fronts so I need the dust cap empty to hold the waste grease. The 11 miles one-way to the lake helps a lot. Lot of info out there to choose from, eg; http://www.thehulltruth.com/boating-forum/119614-trailer-bearing-lube-system-confusion.html


Gary


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## Brainbucket (Mar 30, 2015)

jkeuning said:


> i see this done two ways.
> 
> One way where you start with dry clean hubs and bearings and you pack the grease into the bearing using the palm of your hand, then you grease the races, then you install the bearings and put it all on the lightly-coated spindle, then you tighten down your castle nut, yada yada seals and dustcaps. I might call this bearing-packing.
> ^^^^^yes^^^^^^
> ...


^^^^bearing buddy^^^^^^


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