Poll: How many of you have had your grease seals fail?

[Steve7]

I will be using the Amsoil synthetic grease also when I do mine.

[bartlett]

I've read the entire 47 pages. One thing that pops out is people saying there grease is turned to oil/dripping. And lippart saying this isnt a grease problem. Imo the grease is breaking down and failing. grease should never become a liquid. unless of course its seeing high temps. I dont think this is the problem most are seeing. I think switching to a highend moly grease and only packing the bearings will cure the problem.

[steve gravelle]

Bartlett you have the key to the issue and the total solution, especially when you install quality seals!

[bartlett]

When I get the camper in my hands I will spec out a good seal. Its not rocket science. Im thinking a good national seal with a mechanical inside seal (spring) and a wiper outside seal.

[Cate&Rob]

When I get the camper in my hands I will spec out a good seal. Its not rocket science. Im thinking a good national seal with a mechanical inside seal (spring) and a wiper outside seal.

bartlett - this is essentially what the OE seal configuration is, but not National brand. This style of seal should be able to retain oil as well as grease . . . but it does not. Removed seals appear to be in good shape and have a correct interference fit to the spindle.

Thus the many other theories put forward:
1) Poor quality seal
2) Too much grease
3) Too thin grease (but seal should be able to retain even oil)
4) Grease pushed to the outside of the seal during assembly
5) Seals running dry and lips damaged during initial run in.
In those 47 pages, you will find supporting pictures and evidence of every combination of these ideas..
No one has yet been able to prove the true root cause.

We do know that complete cleanup, handpacked bearings and new seals (of any brand) prevents the problem from reoccurring.

Rob

[Bob/OlallaWA]

My vote is over filling with grease. The grease has to go somewhere as it expands with heat and the only place left is outside the seals. Both the dust cap and the seals in the back of the hub released the runny grease from my axles. Most to the rear because less resistance there then past the dust cap.

[Cate&Rob]

My vote is over filling with grease. The grease has to go somewhere as it expands with heat and the only place left is outside the seals. Both the dust cap and the seals in the back of the hub released the runny grease from my axles. Most to the rear because less resistance there then past the dust cap.

Bob - yours is a theory held by many . . . and I can't prove or disprove it.

Way back in the 47 pages is discussion of greasing through the spindle zerk fitting.
If you believe that this design intent could work, this would mean that the rear seal could turn the injected grease and push it through the bearings and out into the dust cap. The examples that I have seen have a more-or-less empty dust cap. If the seal is not the problem, why would the thin grease go past the rear seal rather than out into the dust cap? I don't know the answer . . . just asking the question.

Rob

[Bob/OlallaWA]

In my case the grease had filled the dust cap and showed signs of leaking past it. Most of the extra grease flowed past the seals and made a big mess of the backing plates, brakes, magnate and inside of drums.

[Chiefblueman]

Same here. The dust cap was completely full and showed signs of leaking. The hubs were solidly packed from dust cap to outer bearing seal. The backside of the seal was full. I don't know how Lippert determines when enough grease has been injected. Even a top notch seal has a limit to how much pressure it can withstand before it allows material past it. From the looks of a couple of my drums I wouldn't doubt if the breach took place at the factory when the grease was pumped in. There was a LOT of grease on them, maybe 1/2 of a cup. Yet the hubs were full from dust cup to seal.

[Likes to tow]

I pulled all four wheels yesterday to take pictures for Grand Design customer service. On close inspection and comparing all four wheels I feel very confident this is caused by the grease! Grease is rated by "dropping point" which is an indicator of the heat resistance of grease. As grease temperature rises, heat penetration increases until the grease liquefies and the desired consistency is lost. Dropping point is the temperature at which a grease becomes fluid enough to drip. End of case! The grease Lippert is using apparently has a dropping point too low for this application. Dexter's web site has an excellent write up on grease and recommends grease with a dropping point of no less than 419 degrees. They have several brands and types recommended and I found the brand I have always used on my previous 5th wheel listed in the write up. It's Valvoline Durablend and I read on the can in my shop that it has a dropping point of 500 degrees!!!! Well above what Dexter recommends. I would think Lippert would have the same recommendations as Dexter. By comparing the two side by side in my hand it was like daylight and dark. The Valvoline felt like stiff grease while the grease from one of my hubs felt like chocolate pudding. I doubt you could use the Valvoline in a grease gun because of it's consistency. However this stuff Lippert is shooting in is more like chasis grease. In my opinion it is the wrong grease and from what the Dexter site reveals it backs up my theory. Grease is also rated in a viscosity index and thickener type. You do not want to combine different greases because of this thickener type measurement plus other factors like additives.

So to sum it all up, wash out all of the old chocolate pudding stuff Lippert is using and put in one of the recommended types Dexter is showing and pay special attention to "dropping point" shown on the can. I checked some other old cans on my shelf and some wheel bearing grease had dropping points of 250 degrees!! I threw all of this stuff away. The grease in my hubs had certainly turned to oil and I have pictures to back it up. As far as these seals retaining oil I'm just not sure about it. Someone with an engineering background may shed light on that subject. At any rate, when I get new brake assemblies from Lippert you can bet the first thing I do is totally wash the bearings and hand pack with Valvoline Durablend after putting in a quality seal. "Easy Lube" hubs are great on boat trailers that get submerged in water but should be outlawed on RV applications!!!!