Wheel Bearings

[LyleB]

This question was also posted on SOI - no need to answer on both forums.

Installed a new axle this past spring. It has about 200 miles on it so far. Recent trip, after driving about 30 miles I felt the wheel hubs. While they didn't burn my hand, they were too hot to comfortably hold on to for more than a few seconds.

Is this too hot? It was a warm day. Didn't notice any odors. I've read that it sometimes it takes a couple hundred miles for the bearings to "seat" and during that time some increased temps may be normal. Just keep and eye on them for now? Do they need to be disassembled and inspected?

Both wheels were similar, wouldn't bad or over tightened bearings affect one wheel, not both?

Still learning about what is normal for these trailers. Plan to take the trailer on a long trip in a couple of weeks, would like to be sure all is well. Your opinions would be welcome.

[Jack L]

First, you need to determine if the heat is generated by the bearings, or the brakes. Using the brakes generates lots of heat, so I try to avoid using the brakes before checking bearing temp. Improperly adjusted brakes can also drag and generate heat. If your 13 foot scamp does not have brakes, the bearings could be too tight. Checking them would be a good precaution.

[floyd]

Are you touching at the hub or the edge of the brake drum?
Do you even have brakes? Two or three seconds of firm touch should indicate a safe temperature at the hub. This is of course a very subjective test but generally effective if not precise.
Brakes work by converting kinetic energy to heat so they will be hot at the drum after several firm applications.
If you want to isolate whether your bearings are too hot you should drive at least a half hour then stop with minimal brake usage and check the hub and not so much the outer edge of the drum.

[LyleB]

The trailer has brakes, but they are improperly adjusted, so they are totally ineffective at this point - virtually no stopping effect. I will be adjusting them myself as soon as I purchase a proper jack to accomplish this. This is a separate, tho I concede, a related issue, but in the present state I don't believe it is contributing to the heat.

Floyd, I can firmly grasp the central hub for several seconds without burning, so I assume this would meet your criteria.

I will be taking it out once or twice before the long trip, so I will keep an eye on it. If I'm still not confident, I will have someone check the bearings, but hate to spend the time/money if this is not necessary.

Thanks, any other opinions?

[floyd]

Originally Posted by LyleB

The trailer has brakes, but they are improperly adjusted, so they are totally ineffective at this point - virtually no stopping effect. I will be adjusting them myself as soon as I purchase a proper jack to accomplish this. This is a separate, tho I concede, a related issue, but in the present state I don't believe it is contributing to the heat.

Floyd, I can firmly grasp the central hub for several seconds without burning, so I assume this would meet your criteria.

I will be taking it out once or twice before the long trip, so I will keep an eye on it. If I'm still not confident, I will have someone check the bearings, but hate to spend the time/money if this is not necessary.

Thanks, any other opinions?

Sounds good.
BTW; You have 7" brakes which are adequate at best when broken-in and adjust properly. They are not nearly as effective as 10" brakes so don't expect lock-up. See them as a pleasant assistant.

[MarkyVasquez]

I just went through a 1400 mile road trip pulling a 17ft Casita at 65 mph and temperatures over 105 degrees. Every time I stopped I touched the hubs where the bearings are housed and they were just a little warm. Their temperature was not even uncomfortable. I could hold on to it all day. Hope this helps.


Happy Camping!
Marky

[MarkyVasquez]

I forgot to post that my drums, inserts , and bearings were new.



Happy Camping!
Marky

[Civilguy]

Lyle,

I had mine done by a shop and it was not the best experience. The manual for my axle said to tighten and then back off 1/4 turn. I checked mine by jacking up the frame after the service and one had no play at all.

I loosened and tightened the retainer and in the event I finally went with 2/12 of a turn. That resulted in a just bit of play when I wobbled the wheel.

I towed 800 miles over ten days in up to 103° and was always able to keep my hand on the hubs when I checked them.

So if the tightness is of concern, you might try checking the play. It's cleaner and quicker than a full repack anyway.

[Bruce H]

Lyle, Just checking, did the new bearings have plenty of grease coated on them when they were installed?

[LyleB]

A good friend of mine who does all his own mechanical work, plus does a lot of work on our ambulances picked up the trailer this morning. He's taken it to his house to check out the bearings and get the brakes working. He agrees with what was posted above, that the factory is often skimpy with the grease, said he's had to pull bearings on new axles before, also had them too tight from the factory. Pretty sure he'll get them squared away. He used to be a contractor and has multiple trailers of his own. He'll deliver my trailer back to me Mon. AM.

Floyd, yeah, I understand that the performance of the 7" brakes isn't great, but I should be able to feel SOMETHING. If I'm going 40 mph, let off the gas and just apply the trailer brakes, I can not detect any braking effect. We'll see when I get them back Monday.

Thanks everyone for your input.

[LyleB]

Final update. My friend returned the trailer, said both bearings were light on grease, so he added some. He also adjusted the brakes and assured me they are working now, but since they are only 7", there is no dramatic stopping power when just the trailer brakes are applied, as expected. He also took it out for a 20 mile drive, or so, said the hubs got warm, but not hot.

I took it out for about a 30 mile drive this AM. Hubs, as he said were warm, but not nearly as hot as they had been after a drive. Also, while the trailer brakes will not stop the truck and trailer in any reasonable distance, I can definitely feel the difference when they are applied and when they are off - a distinct improvement. Much more confident now for my trip.

Again, thanks to all for their comments and suggestions. Good caution to others, do not automatically assume that a new axle will be properly greased or tightened. As my friend said - it depends on the kind of day that the guy at the factory was having when he (or she) assembled them.

[Civilguy]

Originally Posted by LyleB

Hubs, as he said were warm, but not nearly as hot as they had been after a drive. Also, while the trailer brakes will not stop the truck and trailer in any reasonable distance, I can definitely feel the difference when they are applied and when they are off - a distinct improvement.

Lyle,

I think one moral of the story is to be aware of our equipment's conditions and performance even if we are not going to perform repairs ourselves. So, nice job.

Now, if you will just post your friend's phone number here, I've got a list as long as my arm... I hope he welds too.

[Civilguy]

On edit, the information I posted above in #8 is incorrect.

My Dexter axle's service manual cites "approximately one twelfth of a turn" on page 58, not the 1/4 turn I mentioned previously. The reference to 1/4 turn came from another source.

http://www.dexteraxle.com/i/u/614960...d_Bearings.pdf

Another forum member was kind enough to point this out to me.

Now I need to add bearing adjustment back onto that list again...