trailer hubs - should they be hot?

[Cevin c Taylor]

I hauled my '83 CP 16 on a trip of about 4-5 hours over Labor Day, with a stop or two along the way.  The air temperature was in the 80's.  At each stop, I inspected the boat and trailer.  I placed myhand on the hubs of the trailer wheels.  They have Bearing Buddies, and I was careful to fill them with grease per the mfgr's instructions before setting out.  Each time I placed my hand on them, they were very warm.  I could keep my hand in contact with them without getting burned, but probably another 10 degrees or so and I wouldn't have been able to.  Should they heat up at all?  If so, how much?  As I see it, they're spinning at a high rate, and even with grease, the friction is going to cause heat.  We also have a little 4'x8' trailer that we take on vacations to haul bikes, camping gear, etc.  It's much lighter - maybe 400-500 lbs, and has bigger tires, and as I recall, the hubs don't get very warm.  Any insights?

[kickingbug1]

   those little 8 inchers do make the bearing pretty warm but if you can keep your hand on the hubs i see no problem. i always  think that those little tires will give up the ghost before the bearings do provided they are properly greased.

[Greene]

I'm never brave enough to actually touch the hub.  If I can hover my hand within an inch or two without feeling high heat ( there will certainly be warmth) then I jump for joy and keep on hauling.  If you can touch them they are doing great.

Mike

[Salty19]

Your fine wolverine.  Hubs will get warm/hot.  There is still friction between the bearings and races, and tire heat will be absorbed via the rims and into the hubs.  Agree-if you can't hold your hand on them, they are too hot. If they are so hot that you can't touch it more than a split second (like a baking tray out of the oven), do not drive further until you figure out what is wrong. Chances are good the bearing will distruct and you'll probably loose a wheel.

Think how fast those little wheels are turning compared to your tow vehicle.  I imagine they are spinning 2-3 times for each revolution of your car wheel. 

BTW you're doing things right. Check them every hour or so on a roadtrip or if you hear any whining or thumping noise/vibration.
I always stop abuot once an hour to check the hubs, tires, bow winch, other tiedowns, hitch chains/ball/lock and I'll look for engine, transmission and differential oil leaks on the tow vehicle.   I also let the truck engine run during this time to circulate transmission fluid to help keep it cool. 

[skip1930]

" I could keep my hand in contact with them without getting burned, but probably another 10 degrees or so and I wouldn't have been able to. "

Ten deg F warmer puts the hub temp around 160 deg F. [Hot black car on the beach in Reolinda] Hot enough so you can't put your hand on it very long.

So is the grease so hot it's liquid and running out? No?

Your making the bearings work, doing what they are suppose to do. Enjoy the drive.

Is this a CP-19? So 2000 lb boat, plus 400 lb trailer plus 200 lb of junque on board = 2600 lb split among two wheels = 1300 lb. sounds OK. What is the load rating of the tire? Diameter of rim doesn't matter. And air pressure...aired up?

You'll know if they fail. They will weld themselves to the spindle.

Side bar: When in high school we had a lady drive her Cadillac into Bill's Texaco Service and Firestone tire dealer one morning. I took the wheel off and dust cap off. Dry as a bone and yep. She welded the inner race [the outter race does not carry the load] to the spindle. The wheel was barely turning on the outer race with blue balls between the inner and outer races for bearings. They got that hot. So Earl the flat top Marine mechanic grabbed the Mexican smoke ratchet and burned off the spindle assembly and went next door to NAPA and picked up a new spindle, and bearings. An hour later, good as new.

skip.

[Cevin c Taylor]

Thanks, everyone, for the help.  Skip - it's an '83 16'.  I should have mentioned that I work in an office all day, and any yard work I can foist off on my kids, I do.  So, I don't have very tough hands.  In fact, I noticed that this morning while making toast, I couldn't hold onto the toast even after it had been out of the toaster several seconds.  I guess that should be figureed into the equation - my hands can't take a lot of heat, and so the hubs were probably cooler than one would think otherwise.

[CaptRon28]

It would not be a bad idea to buy one of the laser infrared remote heat measuring guns. Harbor Freight Tools puts them on sale occasionally for about $20 or so. I keep one in the truck at all times. When you stop for gas or rest stops or ??, just point the gun at the trailers wheel hubs and look at the gauge. I've seem temperatures as high as 400 degrees at times. Touching the wheels or hubs may not be a good idea. And you DO NOT want to continue driving if you see that. It can easily cause a tire blowout. And it made me convert every boat trailer that I've ever owned to disc brakes. If you ever launch into salt water, you've got to be extremely carefull. The standard drum brakes cannot take it.

[Citroen/Dave]

For those who read older post:

As posted elsewhere, I had one hot hub.  Not terribly hot but the other hub was cool.  The difference in temperature cased me to return to my trailer mechanic for four rebuilds until he noticed after spinning the wheel on the jack, after the installation of the Bearing buddy, that the wheel bearing was too tight.  The Bearing Buddy was pressing on the bearing race. 

Morals of the story:

1.) Always test spin a wheel on the jack after the Bearing Buddy is installed.

2.) The mark on the Bearing Buddy suggest how far to tap the Buddy in after installing it.  Depending on the inside diameter of the hub, this standard mark may drive the Buddy in too deep, pressing against the bearing race.