Repacking trailer bearings

[Ben Brewcat]

Hey handypeople,
I'm trying to add a new skill . From what I read, this is pretty straightforward. I've degreased the bearings and have new grease seals. Question: the inside of the hub, and under the dust caps, is ALL grease. A couple cats I talked to, and the online videos I watch, nothing says to re-pack the whole inner surfaces, just the bearings themselves. Either the previous packer got WAY too crazy with the grease, or I'm missing something. I've repacked the bearings. Once the bearings are replaced (let's say inner bearing), do you pack inside the gap between the grease seal and the bearing? How about the hub?

[AmericasBeekeeper]

Grease fittings usually fill the are you are referring to. You will get grease on the raceways and seals the way you did it. If the area is full of grease it displaces any water that might get in when the trailer is submerged. Good hub seals have a feature to compensate for expansion while rolling down the road and contraction when the hot hub rolls into colder water.

[soupcan]

Also remember that to much grease can create heat.
Heat will cause the excess grease to end up where it does not belong.

[Ben Brewcat]

Oh yeah, I should add that this is not a boat trailer.... lightweight single-axle.

[mike haney]

when grease in the bearings gets hot, it tends to "sling" out of the bearings. highway speeds, combined with small trailer wheels, will actually make even quality bearing grease take on the consistity of water. filling the inner cavity of the hub is intended to restrict the migration of hot (thin) grease from the bearings. its a common practice. good luck,mike

[Klaus]

A couple of pointers; it is messy but it works.
One: put a glob of grease in there palm of your left hand, grab the bearing with index and middle finger of your right hand and push the bearing inner portion of the race through the grease. The object is to force the grease between the bearing surface and the race. Go all around the bearing.
Two: After you do all bearing put them on the spindles, wipe your hand on your wife's favorite dish towel . Look up the nearest marine store or the web for Bearing Buddies. This is a bearing cap that actually has a zerk fitting on it. Now you can grease the bearings without disassembling the
the bearings. This is especially useful for boat trailer bearing as it fills the space between the spindle and the bearings with grease and keeps the water out. Bearings hate water.
Safety tip : It's generally impolite to leave the boat when you are out of sight of land and can't swim.

[Klaus]

Oh by the way, this works good on other than boat trailers. I use then on my utility trailer aand it works great.

[NasalSponge]

I always put some grease in the center of the hub and in the cap to discourge rust, otherwise I do it just like Klaus discribes. You can purchase bearing packers but you end up with just as much on your hands so what is the point.

[Ben Brewcat]

...filling the inner cavity of the hub is intended to restrict the migration of hot (thin) grease from the bearings. its a common practice. good luck,mike

Hmm... seems like a grease gun would be a lot easier than filling all that space by hand . And I think I need a bearing packer now that I've done it by hand... I LOVE needing new tools!

[Beeslave]

Bearing buddies are fine for routinely adding grease to a hub. When you repack bearings the bearing buddies are no good for getting all the needed grease between the inner and outer bearings. Push it in there by hand(finger).

[soupcan]

By all means, hand packing bearings is by far the best!!!

[Beeslave]

A bearing packer is the best for packing bearings. A bearing buddy is nice for maintenance greasing the hub. Your fingers(cheaper grease) or grease gun are best for filling the void between the inner and outer bearings before the outer bearing is placed onto the shaft.

BTW-Excess grease doesn't cause friction and heat. The seal keeps the grease where it belongs.

[soupcan]

We did some real intresting tests a good many years ago with packing wheel bearings & the temp. rise on the hub assy. when to much grease is used.
I would have never thought to much grease would cause this problem but the temp readings showed what they showed.

[Beeslave]

That's interesting.

[BeeCurious]

See what Timken has to say:

http://www.timken.com/en-us/solution...n_Part1of3.pdf

[soupcan]

I worked for a couple of bearing companies some years ago & this was again part of a intresting education I got.
I was always taught to ( fill um up good ) when I was younger.
I then changed my mind set to a 180 degree turn in thought as to what was right & wrong when packing bearings!!!