Greasing New Bearings

[blackmax135]

I had the bearings go bad on me the other day and have gotten one side replace with new bearing and seals.  When I got everything back together and back on i pumped some grease in to make sure there was enough.  After a few pumps the grease started coming out the back of the hub.  I know its hard to answer without being there to see it for yourself but.  I want to know if i messed up the new seal or is this suppose to happen if i put to much grease in.  I do not have a bearing buddy.

[Gotfishyfingers?]

That's normal. Say for example you had old grease in there. Pump new grease in and you will see the old  grease seeping out the back. You will know you repacked it full with new grease, when you see no old grease and only new grease seeping out the back

[fishnkamp]

That is wrong. if you reassemble the seal, back bearing, hub and front bearing all correctly you should pump more grease in through the grease zerk in the axle. The grease should build up in the back and come out through the front bearing. If you see grease coming out near your rear seal then either the axle is badly grooved or the rear seal was compromised. If the rear seal can not keep grease in, nothing would keep water out when you launched your boat. I would remove the hub, clean and inspect everything again ans pay special attention to the axle. Make sure the edges and seal areas have no sharp edges, and the sealing surface for the seal is not heavily or deeply groove. If so that axle will need either a wear sleeve or replacement.  This may be why you suffered a bearing failure to begin with. 

[joefish]

What fishnkamp said.

[Fishing Rhino]

Is your grease fitting in a bearing buddy, or the end of the axle?  It is possible to blow grease past the inner seal if that is the only place it can escape. 

If the fitting is in the end of the axle, grease should not blow past the inner seal.  The grease exits the axle between the inner seal and the inner bearing. From there, it works its way through the inner bearing, the space between the inner and outer bearings and finally exits through the outer bearing.  You should rotate the wheel while greasing the bearings with this arrangement. 

 

[blackmax135]

9 hours ago, Fishing Rhino said:

Is your grease fitting in a bearing buddy, or the end of the axle?  It is possible to blow grease past the inner seal if that is the only place it can escape. 

If the fitting is in the end of the axle, grease should not blow past the inner seal.  The grease exits the axle between the inner seal and the inner bearing. From there, it works its way through the inner bearing, the space between the inner and outer bearings and finally exits through the outer bearing.  You should rotate the wheel while greasing the bearings with this arrangement. 

 

The zert is on the end of the axle.  The side that I have fixed actually looks like everything is new even the spindle.  The seal its self doesn't seem to me like it could hold the grease in if the grease was being pushed in.  Its nothing but a piece of light rubber with a spring rapped around the lip.  

[Al Wolbach]

12 hours ago, Fishing Rhino said:

Is your grease fitting in a bearing buddy, or the end of the axle?  It is possible to blow grease past the inner seal if that is the only place it can escape. 

If the fitting is in the end of the axle, grease should not blow past the inner seal.  The grease exits the axle between the inner seal and the inner bearing. From there, it works its way through the inner bearing, the space between the inner and outer bearings and finally exits through the outer bearing.  You should rotate the wheel while greasing the bearings with this arrangement. 

 

As Rhino says, some axles have a grease channel drilled thru the axle to the inner bearings and have a zerk fitting threaded into the end of the axle. Others have the bearing buddy attached with the zerk fitting. They will not behave the same when greasing if everything is good. 

But with basic hydraulics when grease is put in under some pressure(grease gun) either air or grease must come out. And when the air is all pushed out, the cavity full, grease will come out, usually through the rear seal as it has no place to go. I have seen a bearing buddy pushed out with grease but I think this is rare.

[BobP]

As indicated above, we don't know the exact configuration of your hub.  One tip I have is, when you add grease to your hub, don't pump it in there too fast or you may blow the real seal out, especially if you are pumping in high viscosity marine grease.  Also, you can buy grease seals that have double sealing surfaces.  Not a bad idea.  On my trailer, when full, a ring around the zirc fitting begins to pop out of the hub to tell me it's full of grease.