Bearings packed
Curious what it costs in your area to get double axle trailer bearings packed. I am in New England so especially interested in northeast cost. Not talking repairs to brakes, just a straight up pack th...
Forum Discussion
Grit dog wrote:
Centrifugal force while spinning combined with the grease heating up and becoming less viscous is the actual reason that bearings don’t run out of grease until there is just not enough left or it gets so old and crusty it quits working (like decades old stuff we’ve all seen it where the grease is actually cracked)
I think I disagree with this. Spin a cylinder, centrifugal force would the grease inside would spread evenly on the walls of cylinder. For spinning to force grease towards the bearing, a hub would need to be cast with smaller diameter at center compared to ends where bearings are. And that force pushing grease in would have to push the grease out of bearing to replace it. If seal holds, nothing moves. If seal doesn't hold...
And to the point about grease warming, flowing into bearing; How hot does your grease need to be before it starts to flow? And what is the heat source to flow the grease? IMHO, by the time my quality grease starts to flow, it is to late for grease to save the bearing.
Either system can be used easily to freshen up the grease in a hub and add a little more for necessity or peace of mind.
But to do that requires one to have a little common sense and it helps to know about how much grease is already in there.
Let's use a little of that common sense, see if it should increase "peace of mind", especially if adding grease is necessary.
1 system pushes grease thru outer bearing, hub, (if full) into inner bearing. The other, pushes grease thru inner bearing, full hub, and into the outer bearing. And if you add a ounce of contaminated grease to 3 oz of clean grease, mix, you have a quarter pound of contaminated grease. So, even if the system pushes all the grease that has been in the bearing out, (A Harry Potter idea IMHO) there is contaminated grease on the way to other bearing.
I don’t believe “full” hubs burn up bearings. But they do tend to push grease past the back seal and create more heat and friction.
On this we agree. Plus the work of cleaning all the contaminated grease that has never lubed a bearing out of hub when bearings are properly serviced.
