Hot Hub/Brake Drum

[Pragmatic]

Hi all:
I have a hot hub issue on my Jayco fifth wheel and am not sure of the cause. On my most recent trip, three hubs measured 113-116F with a laser thermometer, and one was 198F. I can think of three possible causes:

1. The bearings might be bad. Before the last trip, I inspected and repacked all bearings. The bearings on the hot wheel don’t have unusual wear. There are no signs of overheating. All wheels have plenty of grease. The old grease didn’t look any different than the other wheels.

2. The (electric with magnet) brake might be dragging. The pad wear on this wheel isn’t any worse than the other wheels. The wheel turns freely without brakes applied, and stops with brakes applied. The self-adjusting mechanism seems to work OK. I’ve cleaned it with brake cleaner.

3. The hot wheel may be the only one which is braking. Entirely possible. Overall trailer braking is poor and has been since the RV was new. All four brake kits are Jayco standard equipment (Chinese brand X). The other wheels all turn freely and come to a stop with brakes applied. The measured temps were only 10-12F above outside temperature. 195F doesn’t strike me as being excessive. I’m only concerned because of the difference between it an the other three.

Any thoughts or ideas?

Thanks, Norm

[Bill Johnson]

Did the nut get over tightened a little causing the bearings to overheat?

[Pragmatic]

I don't think so. I've always tightened my castle nuts the same way: tighten just until snug, then back off a quarter turn or so.

[Bill Johnson]

About the same as me, I just make sure the wheel has no play. This is from Etrailer,
Yes, the temperatures you mentioned are normal. If you were getting over 200 degrees that would be a bad sign. But typically if all of the hubs are the same temperature you're good and it's only really an issue if one of the hubs is hotter than others

[Edutron]

The solution is wet bearings and disc brakes.

[MtnGoat]

So specifically what are the temps of each monitor? Do you double check with IR gun? If so what are those readings? Are you using steel or rubber valve stems? Have you moved the sensor to a different wheel? Lots of factors to generate heat. A dragging brake, wheel bearing, tire alignment.

[LuckyDuck]

We had a similar issue where one hub was considerably hotter than the others during a long trip. I had just put on a new set of TPMS sensors and all were reading normal. Finally, after pulling the caps and checking the tire pressures, I discovered the “hot wheel” was much lower. Pumped it up, pulled the sensor caps and everything was perfect the rest of the trip. One cap was apparently defective, leaking gradually and causing the problem.

[billcf7]

Originally Posted by Edutron

The solution is wet bearings and disc brakes.

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