EZ-Lube hubs

Our fifth-wheel camper has Dexter EZ-Lube hubs, just like nearly every other camper and utility trailer on the road. Over the past five years, I've dutifully greased the hubs every spring. This year, I didn't think the brakes were working as well as they should, so I decided to pull the hubs and inspect the bearings and brakes.

The left side hubs looked fine: There was no sign of grease leaking past the seals. I replaced the seals, put everything back together and adjusted the brakes. But when I pulled the right rear hub, this is what I found:



The brake drum was full of grease. It was a big project to get it all cleaned up. The brake shoes cleaned up OK so I re-used them. The right front hub showed a little grease leakage, but not enough to cause any problems.

I assumed the seal failed from improperly pre-loaded wheel bearings. But when I inspected the seal I couldn't find anything wrong with it; it looked exactly like the seals that had not leaked. The spindle looked fine as well. So I'm a bit baffled why one seal out of four leaked. Also, the brake drum and shoes showed no sign of wear compared to the other three hubs, so this problem has been going on since the camper was almost new. Something may have been done wrong at the factory, but I don't know what it would be.

Note that the seals are double-lipped; grease has to get by both lips to leak past the seal.

Thought they said that couldn't/wouldn't/doesn't happen in the other thread...

The grease is suppose to come back to the zerk area,when you your greasing,when you see that stop,for some reasone it maybe didnt ,there is a good tutorial on the Dexter axle page !!

> Thought they said that couldn't/wouldn't/doesn't happen in the other thread...

I was one of those who said I couldn't see how it could happen unless the seal was bad. And I still don't.

> The grease is suppose to come back to the zerk area,when you your greasing,when you see that stop,for some reasone it maybe didnt ,there is a good tutorial on the Dexter axle page !!

It did. Both bearings were full of grease, as was the hub cavity between the bearings.

Those EZ lube axles are kind of joke in my opinion. My 2019 aluminum toy hauler had about 12k miles on it this spring, so you either use the grease fitting or repack. Decided to repack. One side was fine, still good grease in the bearings brakes looked really good. Other side, not so much. Over greases by someone, pushed one seal completely out and brakes just loaded with grease. The other same thing, but seal remained in place. I never use the fittings, and no one has touched it since I picked it up, so either the dealer or factory did it. I've seen guys pull the cap off and watch for the grease to come out of the outer bearing, trying to be careful, and still push grease into the brakes. Repacking is still the best.

> Over greases by someone, pushed one seal completely out and brakes just loaded with grease.

Given that there's nothing to keep the grease from flowing back out other than the bearings, it's hard to see how enough pressure could develop between the seal and inner bearing to blow the seal out. Unless, maybe, somebody used a power grease gun and just kept it going.

Mark,
I don't know off had how much pressure my cordless Dewalt grease gun can produce. I think it's in the thousands of psi.
I don't think too many seals can withstand that kind of pressure.

I stopped greasing my when I see grease come out the outer bearing. Only greased it once.
I don't use my dump or implement trailer that much. Lucky to use them once or twice in a year, 25 miles or less.

It can happen if you don't stop (hand) pumping when the resistance increases exponentially. BTDT

> I don't know off had how much pressure my cordless Dewalt grease gun can produce. I think it's in the thousands of psi. I don't think too many seals can withstand that kind of pressure.

I'm pretty sure a manual grease gun can produce similar pressure to a power gun. But I think it's a matter of volume, not pressure. There's no reason greasing an EZ-Lube hub should pressurize it. But, obviously, if you pump the grease fast enough you can develop some pressure. That said, the hole in spindle the grease has to go through is tiny, maybe 1/16 inch in diameter, while there's plenty of space in the bearings for grease to get through.

> It can happen if you don't stop (hand) pumping when the resistance increases exponentially. BTDT

I've never noticed any back pressure when greasing one of my EZ-Lube hubs. I pump until I see a bit of grease come through the outer bearing.

Kind of a joke does not cover it correctly.
They ARE a joke.

I believe Dextar states you should jack the tire off the ground to grease the hub.
How many really do that???

The hole exits the spindle between the inner bearing and the seal.
The grease is going to take the path of least resistance.
A little dry grease in the bearing and the seal quickly becomes that path.

With no water flooding (boat trailer) why would you even need to fill the cavity with grease or even grease the bearings every few months.
Car and truck front wheel bearing go 100k easy with just packed bearings and no e z hub.

Pack the bearings close it up and throw the grease gun away.

Now if we were talking a boat trailer that might be different.
Then I would recommend water sealed Vortex hubs.
They have a grease fitting on the outside for the outer bearing and another grease fitting on the back of the hub for the inner bearing.
And they are water tight.

This happens frequently whith those spindles. That much grease is a bad thing and leads to bearing failure as well as the issues you have. I always tell folks not to use those for this very reason. Clean it out and properly pack the bearings with good wheel bearing grease and leave them alone. If you want long lasting bearings the best thing you can do is make sure the wheels turn every month so they don't rust from lack of use.

One reason it's going out the seal is from pressure build up when they get warm. With no air in there and a sealed dust cap, there is only one place for the grease to go when the heat causes expansion. The only reason the others haven't leaked yet is there must still be some air in those.

Dewalt cordless grease gun:
Power through clogged grease fittings with a motor that delivers up to 10,000 max PSI before a pop off valve goes off.

10k psi is a lot of pressure.

(reply to post at 10:13:28 08/30/23)

Click to expand...

Some replies are thinking Bearing Buddies instead of E-Z Lube spindles.

They are not the same.

(reply to post at 10:13:28 08/30/23)

Click to expand...

As you were pumping in grease, was old grease coming out around the end of the spindle?
As easily as it was going in?
If not, it was going past the inner seal.

Was the coil spring inside the seal that failed the pressure?

> As you were pumping in grease, was old grease coming out around the end
of the spindle?

Yes, after the hub was filled. Which took a while the first time I did it.

> Was the coil spring inside the seal that failed the pressure?

The spring looked fine, as did the rest of the seal.

> With no air in there and a sealed dust cap, there is only one place for the grease to go when the heat causes expansion.

The cap is sealed with a rubber plug that will blow out under slight pressure.

Something I learned a long time ago, in a classroom: If it happens, it must be possible.

And if I had a dime for every time since then that a degreed engineer told me something that could be fairly paraphrased as That can't happen!, I could buy lunch for a whole lot of the folks on this board.