Jayco RV Owners Forum

Jayco RV Owners Forum (https://www.jaycoowners.com/forums/)
-   General Jayco RV Chat (https://www.jaycoowners.com/forums/f18/)
-   -   Why our axle grease seals leak. (https://www.jaycoowners.com/forums/f18/why-our-axle-grease-seals-leak-37595.html)

tslarson 06-30-2016 07:05 AM

Why our axle grease seals leak.
 
So I have had some brake problems with my trailer ever since it was new. The brakes on the right side didn’t seem to work as well as the ones on the left side. Temperature checks proved this as the left ones were creating more heat than the right. I have Lippert forward self-adjusting brakes. If I manually adjusted the right side tighter the problem would be reduced for a time and all brake temperatures would be more similar. After a couple hundred miles of towing, the problem would re-surface, and I would have to adjust the right side brakes again. I checked the electrical side of the brakes, and all is ok.
I finally got around to pulling the wheels and drums to check things out. Wouldn’t you know there was grease leaking past the seals and getting on the brakes and drums of the right side wheels (haven’t checked the left yet). I cleaned everything up and replaced the brake shoes. Installed new seals and put it back together. So that lead me to wonder why this is such a common problem with both the Dexter and Lippert axles and their seals. A typical seal should hold about 15 psi of pressure, pretty hard to exceed that while pumping grease in through the EZ lube system unless using an air powered grease gun. I have pumped a few pumps of grease into the EZ lube system, but this problem has existed since new. I have heard of seals being pushed out by the grease pressure, but the seal would have to be loose in the drum bore, but that was not my case. Grease was leaking past the seal and axle shaft. Why?
Here is the answer: The factory seals do not have enough of a “point” where they contact the axle shaft to hold the grease in, certainly not enough to meet the 15 psi standard specification. Could it be that the rubber in the seal is so cheap that the “point” wore off when the trailer made the 1000 mi trip from the factory to the dealer? I think both companies need to rethink the quality of the seals they use in there axle systems. The cure for the problem is just to replace the seals, the seals I purchased at the auto parts store have a significant “point” and will contact the axle shaft properly. The following pictures show my original seal. I painted the rubber part white, you can see how flat the part is where it contacts the axle. The next picture is one I found that represents what the new seal looks like, and how a proper seal should look.

https://www.jaycoowners.com/attachmen...7bff8de263.jpg

https://www.jaycoowners.com/attachmen...abb56ba51b.jpg

Aero_Dave 06-30-2016 08:40 AM

No pictures?

Dave...

RVhiker 06-30-2016 09:21 AM

The pictures are now there.

Unless I'm misinterpreting the pictures, the old seal that came on your new trailer is a single lip seal. The cross section of the new seal shows a double lip seal. EZ lube axles are spec'ed to come with double lip seals, but somehow that's not what your new axles got.

Single lip seals of the proper size can fit EZ lube axles, they just won't hold the grease as well as the proper double lip seal.

bap 06-30-2016 09:58 AM

Part of the problem is over lubing. Wheel bearings if properly packed shouldn't need grease added but very little amount. Then it should only be done once or twice a year depending on the mileage. A grease gun, even a hand powered on can develop way more the 15 psi.

Rootus 06-30-2016 10:05 AM

Quote:

Originally Posted by bap (Post 423781)
A grease gun, even a hand powered on can develop way more the 15 psi.

That's kinda what I was thinking. If you push grease into an already-filled cavity, it's going to hit the seal with a lot more than 15 psi. Even a crappy grease gun should be capable of several thousand psi.

tslarson 06-30-2016 11:57 AM

The seal pictured IS a double lip seal, the lip just is not there, I believe it never was. All the seals I removed were identical. Just a poorly manufactured seal.

I agree that a grease gun can develop a lot of pressure, but not when it just can leak out past the bearing rollers and out the front of the hub. You would have to pump very fast to pump faster than it could leak out. At best you could get a couple of psi. Now a air powered grease gun, that is a different story.

Camping Couple 06-30-2016 03:51 PM

Quote:

Originally Posted by tslarson (Post 423812)
The seal pictured IS a double lip seal, the lip just is not there, I believe it never was. All the seals I removed were identical. Just a poorly manufactured seal.

I agree that a grease gun can develop a lot of pressure, but not when it just can leak out past the bearing rollers and out the front of the hub. You would have to pump very fast to pump faster than it could leak out. At best you could get a couple of psi. Now a air powered grease gun, that is a different story.

So what brand of seal did you get at the auto parts store? I was about to order seals from Dexter until I saw this post. Also, what part# did you use? did the store have to cross them?

tslarson 07-01-2016 04:49 AM

I just brought my old seal to my local NAPA store. They had the seals in stock. There are a few different sizes, so you should do the same. Most auto parts stores carry the seals.


Sent from my iPhone using Tapatalk

tslarson 07-01-2016 06:35 AM

I have 5200/4400 lb axles. The NAPA number is SL325.


Sent from my iPhone using Tapatalk


All times are GMT -6. The time now is 10:21 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright 2002-2016 Social Knowledge, LLC All Rights Reserved.