Trailer Hubs Too Hot?

[FASTFJR]

2005 Karavan Trailer with 2005 Montauk 170. I brought the boat home this weekend to get it ready for vacation. Both wheel bearings were replaced in the spring by the BW dealer. Without the boat in the trailer the hubs were both 118-120F after 30 miles at 65. With the boat on the trailer after 40 miles both hubs were 148-150F, they were fairly hot to the touch. In prior years they just got really warm (I do not know what the temps were). The trailer has not been in the water yet this year. I thought the temp was too high and called my local BW dealer. He had no idea what trailer hub temps run at, so he was no help. I guess my question is are these temps to high? Outside temp was about 80F. The hubs are Sure Lube and are full of grease.

I have not been able to find much information on the web but did find this little bit from etrailer.com

Question:
I have a boat trailer, single axle with 15-inch wheels. The wheels have disc brakes. I would like to know if there is a recommended temperature range for the hubs. My dealer recently serviced the hubs which included replacing the seals and repacking the bearings. On a recent trip I notice that the hub temperature were operating between 148 to 150 degrees. The temperatures were taken using an infrared scanner. This was after returning from a hour ride on the expressway with the air temperature at 90 degrees. My dealer tells me this is normal and that the bearings normal operating temperature range should be between 150 to 190 degrees. Over the pass 25-years Ive never operated my hubs at this high of temperature, normally I would expect to be about 20 to 25 degrees above ambient. Should I be concern or does the higher temperature help with the lubrication of the bearings?
asked by: George last update: July 9, 2008

Reply:
We've never actually checked the temperature using a thermometer, but usually we find that the bearings are hot to the touch, but not too hot to handle. This would seem to put the temperatures you describe on the high side of what we experience, but probably not excessively so. Your dealer is probably on the right track. Are you towing your boat with a lot of gear in it? Overloading your trailer can cause the bearings to become overheated, so make sure you check the capacity of your trailer and ensure that you are not exceeding it.
reply by: Mike


Thanks

[welder]

Are your breaks draging ?

[FASTFJR]

I don't have breaks, I put the trailer up on jacks late this afternoon and tried to spin the wheels. They made it about a 1/2 rotation. Who ever did my trailer check at the BW dealership in the spring must have over tightened the nut. Its going back on Wednesday. Their going to replace the wheel bearings on their dime........I hope

[Kern O]

Running them warm probably did not hurt the bearings, so if they won't replace them, it is no big thing. The seals would be more likely to suffer than the bearings, so keep an eye out for evidence of grease leaking out of the hubs.
The bearings are held in place in the hub by a large nut. If you tap sideways on the bearing cap with a piece of wood, you can remove the cap and the nut will be right there. The nut is never fully tightened and is stopped from turning by a cotter pin or a tab on a washer. If you remove the cotter pin or bend the tab out of the road and loosen the nut one flat, your problem should go away. If you've never done it, have the dealer show you how it is done when you take it in. On my last cross country trip, I checked and adjusted the bearings three times at rest stops. It takes about 3 minutes a wheel and requires a large pair of pliers, a hammer and a block of wood.
While you are at the dealer, pick up a spare bearing cap. They do fall off, and if they do, you will find a spare very handy. Nothing is quite a fun as looking at your wheel bearings because the cap fell off on the way to the ramp. It becomes decision time: Launch and ruin the bearings or go find a cap.