I worded the title in a bit of a confusing way so nobody thinks I’m claiming to be an authority or to have a final answer on the issue, but based on what I’ve observed I have some ideas.
I know it’s not the problem it was, but I think anything to improve our understanding of hubs, seals, and grease helps us out. IIRC, there are two thoughts on the leaking Lippert hubs: One is that they failed to grease the seal surface when installing it, and the other is that they overfilled the hub causing it to blow through the seal.
I’m of the opinion that the problem is poor quality grease which allows the oil to separate from the soap and then leak from around the joint between the outside of the seal and the hub.
So why have I come to this conclusion?
Right after I got my trailer, I tore into bearings and brakes so I knew where I stood. Where I stood was that everything was crap. All 4 wheels had grease on the brake shoes. I ordered new brake assemblies, cleaned everything up and made everything right. I know it was right, because it was 4 years ago, and when I opened everything up last week, everything was in great shape with the exception of a non-functioning brake on one wheel.
What I saw on the original tear down was lots of oil dripped onto the magnets, on the backing plate directly below the axle, on the shoes and concentrated in a small area of each wheel and tire. What I didn’t see was any sign of oil anywhere else on the backing plate or the brake parts or any of the soap base from the grease outside the seal. There was more grease than was needed in the hubs, but I don’t believe it was enough to have caused an issue. My take on that is that it means the leaking occurred while the trailer was parked on a seasonal site for its first three years. Living in Indiana, the trailer had approximately 300 miles on it at the time with no signs of leaking occurring while the trailer was moving.
The TLDR version of the above is that my trailer leaked oil from the hubs on all 4 wheels while it was parked and apparently didn’t leak while moving.
The current tear down showed no signs whatsoever of leaking of any kind.
So in my mind, it comes down to what I did differently than what Lippert did on original assembly:
1. I greased the seals before installing the hubs.
2. I applied silicon gasket maker on the outer surface of the seals before seating them in the hub.
3. I used Mobil 1 wheel bearing grease in a reasonable amount.
Greasing the seals certainly is a good thing, but I genuinely think the leakage occurred around the outside surface of the seals. I used the sealant there because that’s the way I’ve always been instructed to do it on farm equipment gearboxes filled with gear oil. I have seen gear boxes leak oil from the joint between the seal and the box and fixed it with a new seal with sealant applied.
Again, not claiming expertise, but I think it all comes down to the quality of the grease they used. It clearly separated at very low temperature with no pressure. Whether I’m right about it leaking around the seal rather than through it is certainly debatable, but the trivial effort required to apply sealant is IMO a no-brainer.
Feel free to show me I’m thinking wrong or to tell me my genius has saved the entire RV industry :-)
I know it’s not the problem it was, but I think anything to improve our understanding of hubs, seals, and grease helps us out. IIRC, there are two thoughts on the leaking Lippert hubs: One is that they failed to grease the seal surface when installing it, and the other is that they overfilled the hub causing it to blow through the seal.
I’m of the opinion that the problem is poor quality grease which allows the oil to separate from the soap and then leak from around the joint between the outside of the seal and the hub.
So why have I come to this conclusion?
Right after I got my trailer, I tore into bearings and brakes so I knew where I stood. Where I stood was that everything was crap. All 4 wheels had grease on the brake shoes. I ordered new brake assemblies, cleaned everything up and made everything right. I know it was right, because it was 4 years ago, and when I opened everything up last week, everything was in great shape with the exception of a non-functioning brake on one wheel.
What I saw on the original tear down was lots of oil dripped onto the magnets, on the backing plate directly below the axle, on the shoes and concentrated in a small area of each wheel and tire. What I didn’t see was any sign of oil anywhere else on the backing plate or the brake parts or any of the soap base from the grease outside the seal. There was more grease than was needed in the hubs, but I don’t believe it was enough to have caused an issue. My take on that is that it means the leaking occurred while the trailer was parked on a seasonal site for its first three years. Living in Indiana, the trailer had approximately 300 miles on it at the time with no signs of leaking occurring while the trailer was moving.
The TLDR version of the above is that my trailer leaked oil from the hubs on all 4 wheels while it was parked and apparently didn’t leak while moving.
The current tear down showed no signs whatsoever of leaking of any kind.
So in my mind, it comes down to what I did differently than what Lippert did on original assembly:
1. I greased the seals before installing the hubs.
2. I applied silicon gasket maker on the outer surface of the seals before seating them in the hub.
3. I used Mobil 1 wheel bearing grease in a reasonable amount.
Greasing the seals certainly is a good thing, but I genuinely think the leakage occurred around the outside surface of the seals. I used the sealant there because that’s the way I’ve always been instructed to do it on farm equipment gearboxes filled with gear oil. I have seen gear boxes leak oil from the joint between the seal and the box and fixed it with a new seal with sealant applied.
Again, not claiming expertise, but I think it all comes down to the quality of the grease they used. It clearly separated at very low temperature with no pressure. Whether I’m right about it leaking around the seal rather than through it is certainly debatable, but the trivial effort required to apply sealant is IMO a no-brainer.
Feel free to show me I’m thinking wrong or to tell me my genius has saved the entire RV industry :-)
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