I've noticed the last couple times I took my boat out that my wheel bearings seem to be running warm. Its a tandem axle boat trailer with two 3500lb axles. I serviced the bearings the year before last (did not service last year because I only took the boat out once) and the bearings have been running cool all year. Average temp has be been about 100 degrees plus or minus a few degrees all the way around. The last two trips have been about 107 on the front axle and 220 on the rear (rear has disc brakes) plus or minus few degrees. Before a trip, I always top off the grease so that the bearing buddy caps expand out slightly as directed by the manufacture. The only thing I have done differently is inflate the tires to 50 psi. I was running at 35psi which I mistakenly thought the tires were supposed to run at. I dont think that is the issue because I'd think that the bearings would be running the same temp all the way around if that was the case. Is my axle with brakes running hot? Seems strange each axle would be running a uniform temp on both hubs. Thoughts?
Wheel bearing help
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Less PSI in the tire would cause the bearing to run hotter in most cases. It could be the alignment is out slightly and with the added towing weight it's stressing the bearing. When is the last time you had a wheel alignment?
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Originally Posted By: Monster1
The last two trips have been about 107 on the front axle and 220 on the rear (rear has disc brakes) plus or minus few degrees
If I had to guess I would have to say its probably brake related, may be they are being slightly applied by your hitch cylinder brake control.
The last two trips have been about 107 on the front axle and 220 on the rear (rear has disc brakes) plus or minus few degrees
If I had to guess I would have to say its probably brake related, may be they are being slightly applied by your hitch cylinder brake control.
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I would remove the bearings , clean / flush out the old grease and re-pack them with the appropriate " marine " grease . Examine any seals and replace when / if necessary . Re-install the bearings and adjust them properly .
I would do this every year , to get rid of any water that is in the bearing area .
I would do this every year , to get rid of any water that is in the bearing area .
I replaced the rear axle two years ago when I serviced the bearings. One of the spindles got chewed up when the bearings failed. I didn't mention it because I didn't think it was relevant. I've put maybe 1000 miles on the trailer since the axle was swapped and the bearings always ran cool. But I think it's worth a look to see if the axle has shifted. Is a tire shop able to align trailer similar to a car or truck?
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If the trailer is in use the brakes on that axle will drive the temp higher than the axle without brakes. With no load on the trailer drive it around a parking lot slowly without braking and check the temps.
Originally Posted By: StevieC
Less PSI in the tire would cause the bearing to run hotter in most cases. It could be the alignment is out slightly and with the added towing weight it's stressing the bearing. When is the last time you had a wheel alignment?
Why is that?
Less PSI in the tire would cause the bearing to run hotter in most cases. It could be the alignment is out slightly and with the added towing weight it's stressing the bearing. When is the last time you had a wheel alignment?
Why is that?
More drag on the tire puts stress on the bearings which would happen if the tire was under inflated. When it's over inflated there is less surface area of the tire contacting the road so there is less rolling resistance and this takes stress off the bearing.
I was merely letting him know that inflating the tire to 50psi versus the previous 30psi would have the opposite effect if any.
I was merely letting him know that inflating the tire to 50psi versus the previous 30psi would have the opposite effect if any.
JHZR2
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I’m not sure packing grease via the bearing buddy is helping.
This sort of bearing is similar to old cars. My MB diesels have his setup.
I was just working on a single axle trailer last week with someone. Pulled the bearing buddy and was surprised at the amount of built up grease.
Why do I mention my MB diesel? Because Daimler recommends a certain grease mass. Ive observed tons of times that overdosing will result in grease running out and staining he wheels. So it’s getting hot, runny, overheating.
Discussions on the topic indicate that the right amount is important as too much holds heat in. Too much dense grease packed in prevents optimal bearing cooling, which in the case of the car, runs out. I just pulled bearing buddies on the trailer I’m speaking of, and they are a far tighter fit. So they may be less prone to oozing than the MB caps.
Doesn’t take a ton even for a heavy front end car.
Bearings may be too tight as well.
This was packed tight, along with the bearing buddy bore. Not anymore. It doesn’t take a ton.
I know that having the grease in there for submerged applications can be beneficial for displacing water. But with that comes heat.
This sort of bearing is similar to old cars. My MB diesels have his setup.
I was just working on a single axle trailer last week with someone. Pulled the bearing buddy and was surprised at the amount of built up grease.
Why do I mention my MB diesel? Because Daimler recommends a certain grease mass. Ive observed tons of times that overdosing will result in grease running out and staining he wheels. So it’s getting hot, runny, overheating.
Discussions on the topic indicate that the right amount is important as too much holds heat in. Too much dense grease packed in prevents optimal bearing cooling, which in the case of the car, runs out. I just pulled bearing buddies on the trailer I’m speaking of, and they are a far tighter fit. So they may be less prone to oozing than the MB caps.
Doesn’t take a ton even for a heavy front end car.
Bearings may be too tight as well.
This was packed tight, along with the bearing buddy bore. Not anymore. It doesn’t take a ton.
I know that having the grease in there for submerged applications can be beneficial for displacing water. But with that comes heat.
I appreciate all the responses. The reason to add grease to the bearing buddies isn't to add more grease for the bearings, but to keep a positive pressure in the hub because when a warm hub gets submerged in water, it cools and contracts inside which could allow water to get sucked into the hub. The bearing buddy compensates for that. So I've been told. My thoughts are it's something happening with the brakes. On each axle, the temps are uniform. It's not like each bearing has temps all over the place. The only other thing that I think I've been that would change anything is adding fluid to the reservoir on the brake actuator. Maybe I over filled it? These are surge brakes btw. Maybe the actuator is stuck? I think I'll jack up a wheel today and see if a pad is dragging.
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Also. Could the other axle have more weight on it?
It's the brakes dude, one axle 100 degrees over the other and it just so happens to be the one with brakes on it?
Originally Posted By: StevieC
Less PSI in the tire would cause the bearing to run hotter in most cases.
What are the physics behind this claim other than that a hotter tire will transfer some additional heat to the wheel, the hub and the wheel bearing? And why is this effect taking place only in some cases? Tire temperature changes about 10°F per 1 psi.
Less PSI in the tire would cause the bearing to run hotter in most cases.
What are the physics behind this claim other than that a hotter tire will transfer some additional heat to the wheel, the hub and the wheel bearing? And why is this effect taking place only in some cases? Tire temperature changes about 10°F per 1 psi.
I'm positive thats what it is. Question is, why? What are the chances both calipers are sticking causing the pads to drag? I'm thinking maybe a faulty actuator or piston? Do they go bad or stick? Maybe I overfilled the reservoir?
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How many miles since you took apart and manually inspected and greased the bearings? Bearing buddies help keep out water but do not get grease to the inner bearings. There are axles that do but they are Dexter ezlube and i think Lippert super lube axles.
All others must be repacked traditionally.
And yes i think the axle with the brakes will be hotter. I don't see how it would not be.
All others must be repacked traditionally.
And yes i think the axle with the brakes will be hotter. I don't see how it would not be.
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I don't know much about these systems but they do use a emergency locking cable, you may want to check that part of the system out for adjustment, etc.
I would bet it has nothing to do with tire pressure or alignment.
I would bet it has nothing to do with tire pressure or alignment.
I got a chance to look at my trailer today for a few minutes. I jacked up the rear wheels and the brakes are applied when they shouldn't be. Engaging the back up switch does nothing. The wheels rotate so the pads aren't welded to the discs. The bearings and hubs seem ok. I knocked off one of the bearing buddies and the grease looks good. I dont think I cooked a hub or bearings. I checked the fluid reservoir. It's none dry but I can dig out brown pudding with a screwdriver. I'm assuming everything is plugged up with brown pudding and the brake fluid to the calipers are under pressure and can't release. I'm assuming I'll need a new master cylinder and flush the system. Thoughts and help appreciated.
Update: Cracked open the brake line coming off the master cylinder. As soon as I did, brake fluid shot out with a hiss. It was definately under pressure and not allowing the calipers to release. I jacked up both wheels. They spin freely and have the same amount of play since my last bearing service. I got lucky that I didn't smoke the hubs.
Update: Cracked open the brake line coming off the master cylinder. As soon as I did, brake fluid shot out with a hiss. It was definately under pressure and not allowing the calipers to release. I jacked up both wheels. They spin freely and have the same amount of play since my last bearing service. I got lucky that I didn't smoke the hubs.
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Glad you found the problem and are getting it taken care of. It couldn't really have been anything but brake related.
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