Why don't trailers use sealed bearings?

[Utility Beef]

This has been bugging me for a long time, and I searched extensively here, but couldn't find an answer. I apologize if this has been answered before, maybe somebody could point me to the thread?

My experience repacking bearings is fairly limited, but it's not a task I enjoyed, nor one I want to repeat any time soon. It seems bearing maintenance is just accepted as one of those necessary evils and nobody really questions it. Additionally, it seems trailer bearings are prone to failure, even when they've been well maintained.

On the other hand, I've driven many hundreds of thousands of miles in cars with standard sealed bearings. While I've had a few wheel bearings fail in that time, they've always given me lots of warning and have never failed catastrophically.

For the life of me, I can't figure out why trailer builders don't use the same bearing and sealing methods cars do. I'm sure they're more expensive, but they can't be THAT much more. A small premium would be well worth it to me for something I don't ever have to think about again, nor worry about coming apart on the Interstate. I see that Dexter offers Nev-R-Lube bearings that appear to be what I'm asking for, but they're only available on axles too large for TDs.

Is this just a case of "that's the way it's always been"?

-Josh

[Arne]

first, they are cheaper, second, they are cheaper.

There may be a better reason, but I don't know what it might be. I was thinking that most sealed bearings are ball bearings, but I assume the ones on a car are roller, and they must be sealed.

[bobhenry]

The older rear wheel drive front wheel bearings are a tapered bearing largely because they are subjuct to side loads placed on them by a 3000 to 4000 pound car in a turn. Trailers do not experience that and are therefore generally not a tapered bearing. This might explain a bit of the mystery but I have a 3 year old harbor freight 40 x 48 that I have not touched since the day I put it together. I did remove the crap they had the bearings packed in and cleaned them thoroughly and packed them with a 5% molybdenum fortified hi temp lithium grease. Most bearing problems on small trailers are on boat trailers due to the water infiltration and the type of grease. If you service your trailer once a year that is almost overkill every other year is fine for the average road warrior. Water, off road dust , and heavy sand enviroments demand more frequent servicing. I know I will hear about it from others on the forum but 2 years if you stay on pavement is more than adequate.

[nevadatear]

I posed the question to my husband who owns a machine shop and installs and has an inventory of thousands of different bearings. He says it is not a matter of being sealed, but as the previous posters have noted, a matter of "cheap". or quality. The very first thing he did when we started building our teardrop was to take the (and I quote here) "crap cheap bearings" off our Northern Tool axle, and put on "good Timken bearings." And good clean grease. He expects the bearings to last the life of the trailer. It wasn't easy. He had to manufactuer a special tool to get the cap to seal on the bearings, but having a machine shop he can do that, and he feels it was well worth the hour time to do all this, for worry free bearings.

Debbie (talking for Randy at Desert Metal Products)

[Wild Bill]

The Sealed bearings on todays cars are not all that great, you cannot beat a good quality tapered roller bearing properly serviced, I have taken apart bearing sets that have been in service for years and are still in good shape. I agree most of the trailers you see along side of the interstates are boat trailers that get submersed all the time and never serviced. I would rather be able to open up and see what I have every 3 or 4 years than to not know what is going on. Just my 2Cents worth. Bill

[cleonard]

The sealed bearings used in modern pickups (cars too?) are insanely expensive. They are built into the hubs so you have to replace them as a unit. They can cost $300. The older style two part tapered bearings are much cheaper at $10 or so. It's my guess that while more expensive the sealed bearings must save assembly costs.

[Gerdo]

The moral of this story is... Keep your bearings clean and well greased. Grease them often so you lessen the chances of roadside problems. Ignore greasing them and you will have problems.

Been there, done that.

I assumed that since I greased a trailers bearings a few years earler and hadn't towed it that much. The bearings disintegrated on a road trip.