Technical Anyone know what a healthy trailer axle hub temp should be?

I guess I'm a cheapskate. The only time I ever replace a wheel bearing is when it goes bad. and that's only happened a couple of times but not on a trailer. and backing plates? never! and when there's grease getting slung out I replace the seal and wash (including the shoes) everything down... but I'm not a professional hauler with my own equipment. My single biggest problem is these steel belted radial trailer tires.

 

Re temp: it kind of depends on the type of grease you used. If you used a high temp grease, i.e. a lithium complex, then the dropping point of the grease will be somewhere in the range of 500*F, which means the operating temp should be kept below ~300*f. If it is a non-complex grease, say a lithium 12 hydroxystearate than the dropping point will be much lower, ~350 - 400*F, which means you want to keep the operating temp down to around 150 - 200*F.

Bearings themselves will start to incur heat damage around 400*F, which is indicated by discoloration of the steel, starting at a light brownish then transitioning to blue - purple - black depending on the max temp.

And keep in mind that the temperature of the hub is not the same as the temperature of the bearings, which will be much hotter.

So how hot should the hub be? I think the guys already posted good temps, 200 F is probably a good point to start being concerned, especially if you used a low temp grease. I think it would depend on the weight of the load on the trailer, the speed of the bearing (smaller diameter wheels will turn a faster rpm at the same road speed than larger diameter) and whether the hub is braked or not. I suspect some trailers normally run hotter than others, for shits and grins I guess I'll have to take my temp gun with me on the next trip with our travel trailer and see what temps I see.

 

Yes bearings don't die they are murdered ! And there are alot of ways to burn em up and by polling this thread by the posts I'd say 25 to 40 percent treat their trailer as should and that mentality for a trailer builder to save a buck and integrate under-rated bearings and yes the Metallurgical quality also was brought up here . The last I researched we have machinery in United States has 150 year old bearings in it still . Yes it's low RPM machinery but maintained and serviced properly . Let's not forget old grease eats bearing rollers in due time . And where are most trailers stored ? In the garage !! Lol .
As for backing plates they also require a dab'ogrease or fancy it with silicone smeared on the pads

 

Re bearing wear, yes roller (or "non-friction" type) bearings do wear, but not in the same way as plain bearings or bushings wear. There should be no, or very limited, contact between the rollers and the races in a properly lubricated bearing that isn't overloaded or misaligned. The normal wear that occurs under perfect conditions is due to cyclical elastic deformation of the surfaces; every revloution of the roller through the load zone causes the surface of the bearing to elastically deform under very high pressures. Eventually this process leads to cracks that form at the surface that eventualy grow until they meet at some point below the surface which results in a pit. Pits in the surface of a bearing are a normal wear condition that will eventually happen to every bearing. The pits start small, at first they may appear as just frosting of the surface. This will continue and the pitting will grow larger and larger until eventually the bearing fails.

This is why in another thread about repacking wheel bearings I said I like to always clean all the grease off of a bearing when repacking them, so the bearing can be inspected. If the surface is not pitted, the bearing can safely be reused. Just changing a bearing due to age may make you feel more secure, and I don't blame somebody for doing that; a failed wheel bearing in the middle of the desert in the summer could wreck your whole day. But in reality, if the bearing is not showing signs of fatigue when inspected, and if packed correctely with grease and adjusted properly, an older bearing is no more likely to fail than a brand new bearing. If it's not lubricated correctly or if it's misadjusted or overloaded a new bearing will fail as quickly as an older bearing.

 

After 8-9 trips to Bonneville not in a row and good servicing every year I did the full backing plate change out. Worse part was chiseling off the bolts on all 4. I had the drums turned at a trailer repair shop. They still have the same Russian made bearings. I hand pack even though they have buddies. Cost me about $100 at the time.

 

Haha! That's a good one! Your right, most bearings never reach the end of their design life due to mishandling, improper installation, misalignment, improper lubrication, overload or over speed conditions. And yeah, there's a big problem with counterfit bearings being sold that are not up to the application they're installed in. Or mfgr's, or even mechanics, using underrated bearings to save money. I've detected that before for a customer that had me do a post failure inspection, and I found the bearings that were used were under rated for the job; the purchasing guy for the quarry found bearings with the same ID & OD and thought that was good enough. Turns out it wasn't...

 

Wish me luck. If you see a fat guy kicking his trailer on I-40, you might stop and give him a hand…..

 

Regarding replacing the backing plates/shoes etc......I have three trailers, two later model (of this century and a 1972 Streamline (looks like an Airstream), I had checked the bearings and greased them on the Streamline but I hadn't been as detail conscious as I should have been regarding the brakes, especially the magnets. I had pulled the wheels to paint them and replace the rotted tires and decided to really look the brakes over. The magnets were worn, a couple really worn, I didn't even question buying the "kit", it wasn't that expensive and according to the info provided, they were even manufactured in this country.
Bearings?? Well a brother in law used to store his boat in my barn, every year when he came to pick it up he brought new bearings, he greased them well but even with Bearing Buddies they would be rusty and need to be replaced. I've never worried about it...but I don't back any of my trailers into the water

 

We purchased a camper last year to take a few trips in, it has greased bearings in it with brakes on all 4 wheels and weighs about 8000# loaded up. Our first trip with ambient conditions in the 80°F range I drove about 100 miles. All 4 hubs were between 108° - 110°F and the tire tread was 125°F. I read some horror stories on the internet about trailer bearings having just enough grease to leave the factory so I checked them before out next trip. They were very lightly greased when I pulled them off so I cleaned and packed the way I thought they should be. Next trip was 400 miles to Myrtle Beach, we drove non stop in 80°F conditions and the hubs were 95°F. When we came home ambient conditions were 95°F and we made the trip nonstop, the hubs were 105°F and tires were about 130°F on the tread.

Maybe too much info there, but I cant help it, I am an information kind of person and the IR thermometer was cheap at Harbor Freight.

 

Good Luck!!!

You'll be fine.

 

I have duct tape and zip ties, that should cover it.

 

Love me some Red Green Show and Road Kill.

 

I understand packing the bearing; how much grease is put in the hub if any? Does a "bearing Buddy" flush the assembly, fill the hub?

 

Well, hence my question. Man, I think the last trailer I had with ball bearings was a ‘50’s era horse trailer, but tapered bearings are much easier to check. I know things wear, don’t get me wrong, but front wheel bearings in a car can outlive the engine if the bearings are serviced.
Hence the reason I brought up a trailer that is used very little. Stagnet grease is bad and doesn’t circulate/Lubriplate properly.
But a 20 year old trailer that isn’t in daily use, I’ll maintain that servicing it once a year the bearings and races will outlive my lifetime.

 

I used to work on heavy construction plant. I've always serviced tapered roller wheel bearings according to workshop manuals that specify packing the bearings by the palm method, and putting just enough grease inside the hub to prevent rust forming in there from condensation. Advice was to avoid completely filling the hub as churning of the grease can lead to over heating and bearing failure.

I had never heard of Bearing Buddies before (in the UK) and I don't understand how they don't cause the churning problem.

 

I haven’t bought a new tapered bearing in 6/7 years. So cannot confirm if what I’m about to write is still relevant or not.
But if you look at the “wide end” of the taper on the bearing and it’s shiny, it needs to be replaced (along with the races). Bearings had (again, my time frame) and dark, kinda look to them there. I was told a long time ago that when that dark look was gone, time to get another. Wives tale I was told, real world, I dunno.

 

Bearing buddies are more so used in the boating world, there’s a grease zerk that sticks out from the center of the spindle, the idea is (and it works) to keep the whole cavity full of grease. So when you back your trailer into the water to unload your boat, the grease pack inhibits water from coming in.
But it’s not a substitute for repacking then bearings, but just an extra measure to keep water out of them.

 

Newer Dexter trailer axles have something similar to bearing buddies which allow you to grease both the inner and outer bearings with a grease gun fitting like one on a bearing buddy. I'll use them to supplement bearing lubrication but not in place of hand packing with the heel of the palm method. On a side note one of the biggest causes of bearing failure on a boat trailer is the owner immediately submerging the trailer to launch his boat after a long drive at highway speeds. The hubs/bearings are hot from the drive and the cool water temperature will cause water to be sucked into the hub. Or at least that is how it was explained to me by a old time marina mechanic.

 

If the wide end of the bearings taper is shiny yes it's worn and would come from too much preload and a bent axle is going to wear on one side you can sort of see the top of the base of this axle is marked by squishing everything as they drove it home 50 miles

 

Warm to the touch!

 

Funny how threads like this always get way off track!

To the O.P. ....I have carried a "non-contact" laser thermometer for years & from time to time shoot my truck & trailer hubs. Normal operating temps (depending on ambient temps & what grease you are using) are between 105 & 155 on either of my trailers. Keeping in mind I am transporting everywhere in the country from the hottest desert to the coldest tundra. Being that I run so many miles, I have the ability to test different products, procedures, etc. I have found that Mobil 1 synthetic lube grease is very stable, keeps temps down & lasts for as long as I want it to.

Honestly being that I am really anal about my maintenance, I NEVER have bearing or tire issues on my 2 trailers! This particular enclosed trailer has been in my service since 2014 & only ONCE in over a million miles did I have a bearing failure. Coincidentally....I have only had ONE flat tire on the road in those million + miles & that was caused by a brake magnet malfunction which locked up the wheel in the middle of winter with snowy roads, so I didn't notice the problem until the tire blew.

Even though one of my trailers has "bearing buddies" I think they are a detriment! They make people even more lazy than normal, because they think they can just pump grease into the zerks & never worry about the bearings again!

Another thing that I think helps with my success when it comes to bearings & tires is th efact that I run aluminum wheels on both trailers & they act as a big "heat sink" helping to despurse the heat from the hubs.

@BamaMav I would normally agree 100% because there are way too many "parts changers" & not enough actual mechanics out there. However in this case it makes perfect business sense to replace a "loaded" backing plate VS shoes, magnets, star adjusters, etc,etc as it is much less time consuming & also cheaper if you add up all the pieces on the loaded backing plate! I can change one in ten minutes or less if my trailer is jacked up in my shop for under $50.00 & for me, they last 50/60K miles easily!

God Bless
Bill
https://www.jalopyjournal.com/forum...ar-transport-hauling-open-or-enclosed.614419/

 

Ain't a bearing directly attached to an axle which affects wear when not geometrically sound ?? You would be having alot of fun on Red Bones just don't forget your knee pads !

 

The good news is Root made it to San Diego with zero issues Other than near heart failure when he saw the price of gas once he crossed the border into CA.....

 

The answer to my question is 82*. That’s what the hubs averaged for the whole trip.

I made it to San Diego. 1300+ miles. Now to make it home.

 

If your travelling the 40 right now it's probably windy as you hit the upgrades be safe and patient

 

I guess you will have to explain what your response means or has to do with my post. Maybe I am having a brain fart, but I don't get the correlation.

God Bless
Bill
https://www.jalopyjournal.com/forum...ar-transport-hauling-open-or-enclosed.614419/

 

You can doo it!

 

you spoke of this thread heading off subject so I wondered perhaps you thought I was a culprit on this since my posts preceded your post . Now you do know of course I am joking about the Red Bones they are high precision skateboard bearings this necessitate knee pads or knee surgery LOL . Now Red Bones are of course way off subject but I can tell you if you put them on a wheelchair you will easily hit 40 mph in that wheelchair . Well it's been a nice thread with centuries of knowledge and experience here and a big applause for Roothawg surviving our gasoline racketeering here in California !! Lol
Take care Bill and God Bless

 

Now tell me where I put my laser temp gage! I normally hang it in one place so I can find it; I guess I be abbynormal.

 

Thank You Freddie!

No, I did not have anyone in mind specifically & was just making a general statement...not good or bad.

I actually searched Red Bones.....I saw a restaurant, a fat black woman wearing clothes that were way too tight for her & the bearing company, However I did not read far enough to see that it was a skateboard bearing company! I took the knee pads comment to be about servicing another man! LMAO!!!!

God Bless
Bill
https://www.jalopyjournal.com/forum...ar-transport-hauling-open-or-enclosed.614419/