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dmac · 05-07-2006, 08:40 AM

Yesterday I decided to repack my wheel bearings for the first time. Yes, I know I'm about 2 years late. But we have not had the opportunity to use the trailer much and have mostly kept it stored indoors.

There was plenty of grease in the bearings, plus about 1/2 lb extra in each hub. Some of the grease was a thin consistency, like heavy cream. In two wheels the grease had leaked past the grease seal and made a big mess in the brakes, a third wheel had evidence of leakage starting at the seal, while the fourth wheel was fine. I used 2-1/2 cans of brake cleaner, an old toothbrush, and lots of time to clean up the mess. I probably should have replaced the brake shoes, but decided I would try cleaning first. I cleaned and repacked all bearings. I put some extra grease on the bearings - but not in the hub like the factory had done. I installed new seals and put it back together.

Even if you have a newer trailer, repack the bearings immediately - just to be sure it is correct. Improper grease and/or seal failure causes leakage, which gets all over the brakes and makes them useless.

overlander63 · 05-07-2006, 08:46 AM

Sounds like yours may have been one of the "recall trailers" with the underlubed bearings, and an overzealous tech shoved waay too much grease into it. Did you replace the seals when you did the clean and repack? It would be a very good idea, especially since the grease had been forced past them.

Pick · 05-07-2006, 02:23 PM

Some folks have a tendency to overpack wheel bearings, such as what you describe, dmac. All you really need is to pack the bearings themselves. Putting big gobs of grease on the axle between the bearings, serves no purpose whatsoever. You are almost guaranteed to ruin the seals getting them out of the hubs and you need to do that to remove the large bearing, so replacing them is a must.

dmac · 05-07-2006, 05:22 PM

As mentioned in my original post, I did replace the seals.

It is interesting that three of the original seals had a blue outer rim, and the fourth had an orange outer rim. The orange one is identified as National 41290, the blue ones had no identification that I could find.

A local RV dealer (non-Airstream) had Tekonsha branded seals. The one identified for Dexter 12" brakes had an inside diameter that was too small. However, I found a different one that fit. Only single lip and no spring, but they were available at the moment I needed them!

Beginner · 05-07-2006, 06:27 PM

Over the years I have noticed that when the bearings were packed but no grease was smeared on the spindle between the bearing races and in the hub between the cups that these areas rusted.
When I removed my drums to have the studs installed these areas were rusted.
When I repack bearings I always apply a light coating of grease on these unused areas (take my finger and smear it on until coated with a thin film). In my mind rust in the bearings just dosen't sound right.
The center of hub breathes or the moisture wouldn't be present ant these two areas would not be rusted.
Overpacked bearings run much hotter than properly packed bearings.
Overpacked bearings are what you get when you use Bearing Buddies and just keep pumping the grease in.
In the bearing buddy case the bearings are full of grease and the entire hub is full of grease with no air pocket at all. This is an advantage on boat trailers that don't see much highway use because there is no room for water intrusion.
However nowdays we have grease that does not absorb moisture or washout.
Remember even the oil lubericated hubs have an air pocket as the hubs are only about half full of lube.
These oil hubs are becomming more and more popular on the tractor trailers.
Southwest Trailer sells both sizes of the seals needed for the Airstream #42 hub and at very good prices along with bearings, cups, lug nuts, and dust caps enough for an axle for about 20.00 bucks as I remember.
Beginner

scottanlily · 05-07-2006, 08:11 PM

Hello beginner,

bearing buddies are great for boat trailers ,I do alot of trailer bearing service in my line of work and the water will get in by the sudden cooling of water as the trailer is submerged ,a vacuum sucks the water in ,the light pressure applied by the buddies counters this suction .The blue grease for boat trailers alone cannot protect from water .If water gets in you,ll have trouble ,i see it alot ,my own 4x4 scout rusted the bearing after some 4 wheeling crossing some deep streams,Water sucked in the front hubs .Todays grease cannot stop water damage.I dont know about overpacked bearings running hotter ,why would that be?always be creful about mixing different types of grease,that mixing breaks down the grease resulting in the creamy slimey mess you will see in your hubs,as the base stock or soaps as its called are not always compatible in the greases .the label on the can tells the makup of the grease you are getting in detail .One other note is that tekonsha seals come in the double lip as well ,they retain the grease much better than single lip ,I always use those unless they are not available.Yes dont over grease!

Scott

Beginner · 05-08-2006, 11:11 AM

According to a Bearing School that the NAVY had many years ago (73-73 time frame), bearings pressure packed in the hub overheat. This was in reguards to the overgreasing of electric motor bearings(ball) and others(roller, similar to trailer wheel bearings). Stated that the heat difference was enough to liquify the grease causing it to go past the seal eventually causing failure of the bearing not to mention the brakes.
This sentament was was echoed by the office trailer rental business that sold me the Vavoline Optimum Choice Grease that I repacked my bearings with.
Beginner

Inland RV Center, In · 05-08-2006, 12:03 PM

Quote:

Originally Posted by dmac

Yesterday I decided to repack my wheel bearings for the first time. Yes, I know I'm about 2 years late. But we have not had the opportunity to use the trailer much and have mostly kept it stored indoors.

DMAC

Brake shoes are very porous.

Once they have been exposed to grease, they are done.

Yes, you can soak them in gasoline or other solvents, which seems to remove all the absorbed grease.

However, once the shoes get hot, you will usually find that more grease has come to the surface of the shoes.

Brake shoes are not that expensive, when you add the safety factor to them.

Replace the shoes. You will be glad you did.

Your situation just confirms, again, the need to repack bearings every year or every 10,000 miles, REGARDLESS.

In your case, you would have stopped the problem before it started.

Andy

Beginner · 05-08-2006, 01:41 PM

I agree with Andy. I've seen cleaned brake shoes (the brake material or course) brake up after cleaning/soaking in various solvents?

dmac · 05-08-2006, 02:58 PM

I agree with Andy that some grease has worked it's way into the friction material and may continue to prevent them from working properly. The answer is to replace the shoes.

I would hope that brake cleaner spray would not ruin brake shoe friction material! It is routinely used to clean brakes for inspection.

Inland RV Center, In · 05-08-2006, 03:00 PM

Quote:

Originally Posted by dmac

I agree with Andy that some grease has worked it's way into the friction material and may continue to prevent them from working properly. The answer is to replace the shoes.

I would hope that brake cleaner spray would not ruin brake shoe friction material! It is routinely used to clean brakes for inspection.

Dan.

Your correct, but dust and dirt, not grease.

Andy

**Action** · 05-08-2006, 03:42 PM

Brake cleaner will remove grease from brake friction material. And only the surface. The friction material will absorb some grease and there will be a loss in braking performance.

A hub full of grease will not release absorbed heat that has been built up versus a hub that has air space with no grease in it.

>>>>>>>>>>>>>>>>>Action

overlander63 · 05-08-2006, 03:44 PM

Quote:

Originally Posted by dmac

As mentioned in my original post, I did replace the seals.

Yes, you did. My bad....

Rob30044 · 05-08-2006, 04:51 PM

Andy,
What kind or brand of grease do you recommend for packing wheel bearings?

Thanks,
Ben

Cracker · 05-08-2006, 05:51 PM

I had the identical problem when I repacked the bearings in my 2000 30' Excella - and I think I made an earlier comment thereon. Somewhat unbelieveable that the Mother Ship would allow someone to pack wheel bearings without proper training. Are the axle assemblys, with brakes and drums, furnished by others to the MS?

overlander63 · 05-08-2006, 05:58 PM

Quote:

Originally Posted by Cracker

Are the axle assemblys, with brakes and drums, furnished by others to the MS?

They are shipped with the bearings installed and prepacked from Henschen or Dexter.

Cracker · 05-08-2006, 06:04 PM

Geeezzz!!!

Now who do we look to for advice on packing wheel bearings???? This is like GM shipping new cars out with 10 extra quarts of oil in the crankcase! (Note: I could just as easily have said Chrysler or Ford!)

overlander63 · 05-08-2006, 06:31 PM

Quote:

Originally Posted by Cracker

Geeezzz!!!

Now who do we look to for advice on packing wheel bearings???? This is like GM shipping new cars out with 10 extra quarts of oil in the crankcase! (Note: I could just as easily have said Chrysler or Ford!)

Who says they don't? I drained 2 extra quarts out of a new Ram 1500 this morning...

Beginner · 05-08-2006, 08:01 PM

overlander63
Be sure that wasn't a case of the wrong dip stick that caused the oil level to be wrong. I have run into this with GM products.

axleman · 05-08-2006, 08:15 PM

I too agree with Andy - replace the shoes.

In the axle manufacturing process (most that I have seen) hub/brake assemblies are prepared off line in the "Pit Station" for grease and the "Brake Station" for brakes. This allows the sub-assemblies to be installed on axles that go down the production line. Most manufacturers of axles buy grease in large containers that are hooked to the "Pit Machine". This machine incorporates several processes to aid and speed up production. The brake drum comes with races installed by the manufacturer, inner and outer bearings are installed by the operator and so are the grease seals. Step one presses the assembly together - step two adds a predetermined abount of grease. Perhaps I understand how the supplier to the "Mother Ship" made the error. Different capacity axles use different size bearings (IE: 3500# axle bearings require less grease than 7000# axles). So a set up is required when changing drum sizes. If an operator lacks to change the set up and put enough grease for a 7000# axle into a 3500# axle the result is over-greasing. Dang humans - they can be so problematic!!!!!

Regards,
Henry