How hot should bearings run

[Chicken Legs]

The guys are right in saying that if a bearing is too hot to touch its too hot. A little info- you can't touch and hold hot metal @120 dg. and above. You can touch at 110 not easy but you can do it for a period of time. The bearing temp. will change with different conditions but still should be able to touch.

[rockwood06]

Take this for what it is worth, a few years ago I had lost a wheel bearing and had to replace the axle after I completed the work i spoke to a Tech at Alco who manufactured the axle and wheel assembly, he said it is normal for temp on the bearings to reach 180 degrees on the high end of the scale. If you ride the breaks the or in stop and go traffic the wheel assembly will stay hot. Remember, brakes on a camper are not self adjusting, I know the question is about bearings but this is just one thing that will effect temp on the wheels. When I re-pack my bearings I used RTV grease. In some cases depending on who did the bearing work if they tighten the nut down too tight it will cause the bearings to run hotter.

[gbpacker]

After having my bearings re-packed by my dealer this spring I experienced a burning smell and very hot wheel hubs after a 50 mile trip. On the return trip we stopped at the dealer for an inspection.

Dealer told me that sometimes after bearing re-pack, the brake shoes drag, heating the brake drums and hubs. To correct the problem, I was advised to back the trailer and apply the trailer brakes with the manual control lever on the brake controller. This will force the brake shoes to rock backwards, unlocking the brake shoes.

[DDC]

"" I was advised to back the trailer and apply the trailer brakes with the manual control lever on the brake controller. This will force the brake shoes to rock backwards, unlocking the brake shoes.""
I would stay away from this dealer they don't have a clue,I've been a mechanic for 40+ years and this statement is just pure wrong and based on stupidity.

[Herk7769]

Advice like that got me into the worst aircraft mishap of my career.

After several high gross weight assault landings with me in the command seat, we landed and switched pilots so my "copilot" who outranked me at the time, could get his landings in. Once the seat swap occurred, command of the aircraft switched to him.

We started to taxi out and the brakes would not release because they were hot. My advice to the new commander was to call the fire department and have them watch while they cooled enough to release.

He looked at me like I had horns on my head and told me that at his previous base in Texas, this happened all the time. They just advanced power to a higher power setting and they would "pop" free on their own.
I was VERY skeptical, but he was the boss. He did; and they did. A short taxi later using no brakes in order to let them further cool we took the runway.

At about 135 MPH, our aft right tire exploded and darn near destroyed the plane. Past our abort speed, we took the crippled plane into the air; circled while the fire department got ready; and landed right on centerline.

Dragging brakes are NO JOKE.

[jbirrell]

You asked for specific temps. I check my trailer wheels at most rest stops and usually see temps in the 100 to 125 degrees. Depends on the highway temps and how hard I braked to come in. I am much less worried about exact temps as I am the range. If three are about 100 degrees and one is 150, I may well have a problem with the hotter one. I use a Harbor Freight laser temperature gun (about $25). Works well.

[2011 Powerstroke-Wildcat]

Thanks Guy's great information, but I'm sometimes not as clear as I need to be so let me try once more! Not your fault, mine.

Had tire failure, Cheap tires, replaced! Tried to service bearing on trailer! Could not, they are sealed bearings from the factory, bearing races and seals come as (1) one unit, pressed into hub. When you remove the nylon lock nut from the axle (NOTE: Not the normal Key type nut with cotter pin) the entire hub, drum and everything comes off! Could not repack the bearings at all. Of the four wheels I pulled three had very little grease at all in them!

Using High Temp grease and two fingers I tried to pack the inner and outer bearings inside the hubs before replacing them back on the axle. Replaced the big flat washer and nylon nut tighten the nut and then backed off 1/4 turn.

Now here is the issue and my question! These new nylon nuts have to be torqued down to between 180-200 ft-lbs. When the tire blew and I jacked the wheel up off the ground the entire hub moved 1/4 to 1/2" in all directions. The shop who replaced the tire advised me this new bearing is different and the hub nut needs to be torqued down. He checked all four wheel and the other three were also just as loose. Using an Impact gun he torqued the hub nuts down. When I returned home I used a torque wrench and set the torque on each hub at 180 ft-lbs. My hub temps with the temp gun shows between 95 to 120 degree's after about an hour on the Interstate. Is this about right or in the neighborhood? With your past replies it seems I'm Ok with bearing temperatures! Has anyone else had any experience with these type of bearings?

My vehicle mechanic advised most all new cars and trucks are coming equipped with this type of bearing assemble, but mine was the first time he had seen them used in trailers!!!

Just wanted to see if anyone had any experience with them or knew of a way to maybe extend their life by forcing grease into them! Because what I have seen when I pulled mine, you may get three years out of them and then you will be going to a machine shop to get the old ones pressed out and new ones pressed in! If you are lucky and don't burn an axle up first!

Once again sorry for the confusion, I'm new to these forums and know all of your time is valuable. But be aware these things are out there!

Be safe and Thanks to all!

[DDC]

Just pack as much grease as you can into them and keep them torqued there should be no play or looseness in these bearings they will not last as long as tapered bearings thats why the automotive switched "cheaper".

[prof_fate]

Originally Posted by jbirrell

You asked for specific temps. I check my trailer wheels at most rest stops and usually see temps in the 100 to 125 degrees. Depends on the highway temps and how hard I braked to come in. I am much less worried about exact temps as I am the range. If three are about 100 degrees and one is 150, I may well have a problem with the hotter one. I use a Harbor Freight laser temperature gun (about $25). Works well.

WHile I don't have such a guage (been tempted..) last check I had the same thing - one hotter than the others (measured by touch). The TT is at the campground for a month or so and I'll check the temps again on the ride home next month - could be a slightly tighter brake adj or bearing adj or grease issue, or just a random issue.

Do you ever measure tire temps? Can this identify a more loaded side/tire? A low air pressure tire?

[prof_fate]

Hadn't heard of them used on trailers, but I guess it was inevitable. They are WAY better than the old tapered roller bearings.
They don't need greased - every front wheel drive car I've seen for then past 20+ years have them in the front and there is no way to grease them - and they'll last 100, 150, 200,000 miles no problem.

Again, they're sealed - dirt is the enemy more than grease being their friend.

Originally Posted by 2011 Powerstroke-Wildcat

Just wanted to see if anyone had any experience with them or knew of a way to maybe extend their life by forcing grease into them! Because what I have seen when I pulled mine, you may get three years out of them and then you will be going to a machine shop to get the old ones pressed out and new ones pressed in! If you are lucky and don't burn an axle up first!

Once again sorry for the confusion, I'm new to these forums and know all of your time is valuable. But be aware these things are out there!

Be safe and Thanks to all!

[2011 Powerstroke-Wildcat]

Thanks to all who replied, and to DDC for the advice. Just wanted to let everyone know about the change in the bearings. Through me for a loop when I pulled the dust cover and seen the nylon nut and not a castle nut! And to HERK7769, WOO and I thought I was have a bad day with a tire blow-out! Look forward to conversing in the future! Be safe and thanks.

[SpringerPop]

I suspect that any reference above to nylon nuts should actually be called NyLOCK nuts. They are still steel nuts, but have a small plastic insert to act as a thread locking device.

I'm going to then assume that the O/P's trailer has sealed-type hubs. I, too, have not seen them used in trailer service, but new stuff happens every day.

The front hubs on my 4WD F-350 are of the sealed, lubed-for-life type, too. "Life" is not MY life, nor the truck's life, just the bearing's life. It could be extended considerably if they could be lubed in a conventional way.

We have found a way to do this on our trucks by removing the ABS sensor and pumping the cavity almost full of a quality GC-LB #2 lithium-complex grease. I use Delo Grease.

I have 209,000 miles on one of mine (the other one failed at ~120,000 before we started lubing them), and there's not a hint of looseness. Many others obtain similar results.

I suspect that sealed hubs are easier for an OEM to deal with, but in the long run more costly to the end user. They are also a boon to the bearing manufacturer's sales figures.

If/when I someday end up with a trailer with sealed hubs, I will figure out a way to get the lubricant occasionally replenished.

Who knows, by then there may be ABS mandated on travel trailers!

Pop

[prof_fate]

sealed bearings (and ujoints, tie rod ends/ball joints) last longer than a greasable one and incur no maintence costs. For the overwhelming majority of people this is way better than having to have things lubed (and not having something skipped, over-lubed with grease blowing a seal letting in dirt/moisture). And with wheel bearings of the old type they'd often be pulled part for brake work or other 'inspections' enabling contamination (or the customer would be advised- and charged-for bearing repack).

I don't recall many wheel bearings of the old type lasting 80k miles let alone more. My last taurus got them at 135k, current one got one at 110k the other is still good, my windstar is at 108 with the original bearings and no issues (inspected last week). My expy has 236k on the original bearings.

Having been a tech in the early 80s then working as a service advisor/manager in the early 2000s I can attest there is world of improvement in almost every aspect of cars today, wheel bearing included.

Like so many I know that complained about electronic ignition, how expensive it was to replace when it failed. Do you remember points? Remember needing a tune up every 10 to 12k miles? Remember having condensation get into the cap and having wet points and needing a tow? When was the last time you had a tune up?

[OldCoot]

Originally Posted by prof_fate

sealed bearings (and ujoints, tie rod ends/ball joints) last longer than a greasable one and incur no maintence costs. For the overwhelming majority of people this is way better than having to have things lubed (and not having something skipped, over-lubed with grease blowing a seal letting in dirt/moisture). And with wheel bearings of the old type they'd often be pulled part for brake work or other 'inspections' enabling contamination (or the customer would be advised- and charged-for bearing repack).

I don't recall many wheel bearings of the old type lasting 80k miles let alone more. My last taurus got them at 135k, current one got one at 110k the other is still good, my windstar is at 108 with the original bearings and no issues (inspected last week). My expy has 236k on the original bearings.

Having been a tech in the early 80s then working as a service advisor/manager in the early 2000s I can attest there is world of improvement in almost every aspect of cars today, wheel bearing included.

Like so many I know that complained about electronic ignition, how expensive it was to replace when it failed. Do you remember points? Remember needing a tune up every 10 to 12k miles? Remember having condensation get into the cap and having wet points and needing a tow? When was the last time you had a tune up?

Definitely agree with the electronic ignitions being much better, but in all my driving since 1955, have never had to replace a front wheel bearing although I have had to replace a couple of rear axle bearings that were sealed on one side. I prefer the tapered roller brgs for the front wheels on rear wheel drive cars.

[2011 Powerstroke-Wildcat]

Pop you assumed right, was not sure of have to spell the correct name. Thanks for the help. I just forced as much grease as I could between the inter and outer bearing as I could. There seemed to be a gap of about 3/8 to 1/2 inch between them. Then I slid the hub back into the axle packed a little more on the outside, then replaced the flat washer and Nylock nut back on. Just did torque the nut like I should until I spoke to the mechanic and found the info on Lippert Components Web site. They are called SBS (Sealed Bearing System). Thanks for the help and Info.

[grayfox]

Not to change the subject, but I love those Springers, Cockers and Brittanys .

Beautiful dog POP

[prof_fate]

Grease in not all the same - some kinds are not compatible with one another. Make sure what whatever type you added is the right 'base' as what was in there or you can cause more problems than you're trying to solve.

[SpringerPop]

Originally Posted by prof_fate

Grease in not all the same - some kinds are not compatible with one another. Make sure what whatever type you added is the right 'base' as what was in there or you can cause more problems than you're trying to solve.

The Professor is sure right about grease compatability! If you are going to re-grease serviceable bearings you are well-advised to completely clean all the old lubricant from the bearings to ensure you only have one thickener type, and not a mix. Ford (actually Timken) uses Mobil Infinitec 152, which is lithium-complex based, so I know we can use Delo. Here is a chart of thickener compatability.

I do not agree with him, however, at the assertion that newer, non-servicable, bearings will last longer due to no moisture or dust incursion. As long as conventional bearings are properly maintained, they last a very-long time indeed. Of course, the key is maintenance, and if you don't wish to do it, you pay the price. The Professor rightly called the maintenance schedule for the "overwhelming majority", i.e. run it 'till it breaks then replace it. That works, but it's just usually more costly and time-consuming that way. I prefer to do maintenance on MY schedule, not (pardon the pun) fate's.

A complete cleaning in some kind of solvent (I use diesel fuel) is a good idea to enable you to carefully inspect the rollers and cones for any wear or pitting. It occasionally happens, and I encountered it just last month on an outer.

When spotless, besides a visual inspection, I usually run the dry roller assembly against the cone and feel for even the slightest irregularity. If it doesn't run completely smooth all the way around for a few turns, it gets replaced!

Maybe that pitted bearing would have made it the mere 200 miles that we were going, but I don't make it a habit of finding myself along the side of the road, either, and do what I can to prevent it from happening.

Sealed units may be the wave of the future, but I think we're going to see more roadside hub failures as a result.

YMMV

Pop

[SpringerPop]

Originally Posted by grayfox

Not to change the subject, but I love those Springers, Cockers and Brittanys .

Beautiful dog POP

His name is Buddy, and he can be found here:

Now, back to our regularly-scheduled discussion on bearings and hub over-heating problems.

Pop

[thebrakeman]

Looks like I found the right thread.
I just finished checking brakes & bearings, reset the bearings according to instructions here, adjusted the brakes, and replaced all 4 tires...this in prep for our 2 week trip, leaving next weekend. I did the 20 ft-lb, back off, 7 ft-lb, install pin procedure. If in doubt, I backed off to avoid high temps.

I just took a test drive...only about 10 miles. All 4 hubs felt the same...too hot to touch for more than 1 second. But, I was adjusting the Prodigy brake controller on my way back into the subdivision. Plenty of full manual stops. I'm driving it again tomorrow on the way to work, and will check again with normal driving (light on the brakes).

1. Can fiddling with the brakes make the hub shaft too hot to touch?
2. Thinking about getting a IR temp gun at Harbor Freight. My camper has the little plastic hub caps. Do you guys run without any caps, so you can get temps right on the cast hubs?