there’s a lot of good thoughts to unpack here, so I’ll try to respond as best I can.

there could have been some crud stuck to it which caused the leak. I cleaned them off as best as anyone can but there is always that chance. There’s also a chance that a quick smack with a hammer would have stopped the leak. But from past experience, a new cap will stop the leak and given that we were on the road with it leaking slightly for 300 miles already, replacing it was the best bet. And it worked. No signs of leaks in the nearly 1000 miles since I replaced the cap.

I’d love to have a tool to install them. I may make one when I get home. I’ve recently just been using my bearing/seal driver kit to install them as that seems to work better than just tapping them with a hammer, even a urethane. Had better luck with them since I started using the driver.

I do take them off when using the easy lube system. My first attempt at greasing (flushing really) with the easy lube forced them to leak grease past the inner seal on every trailer I touched. Not a lot, and they just leaked the first time down the road, but it was pretty apparent that with the entire cavity full and the cap completely full, that they were flat out too full and would leak the first time out. Since then I pull the cap using a sharp chisel as a pry tool at the hub. I don’t drive the chisel into the cap, but rather just use it as a sharp screwdriver and gently pry the cap forward. Then wiggle it off once it’s started. Then I flush the bearings and wipe all the excess grease off the front side of the bearing. When I put the cap on, there is no grease showing on the front side of the bearing or nut. I use a paper towel folded up into a tight crease and roll the grease out by spinning the wheel both directions. Cap goes on clean and dry. By doing this it allows the cap to catch any grease that gets pushed forward while in use. So the hub is as full as it can be without being so full that it pushes it past the inner seal. This is really easy to see when you don’t have brakes.

as to the need to be full … I am 100% convinced that they need to be full because it has saved my bearings more than once. Twice now I’ve had an inner seal fail without warning. As expected, it slung grease all over the inside of the wheel. Once it happened in a rain storm and the hub got water in it from the leaking seal. In both cases the. Bearings were fine because the excess grease in the hub cavity kept the bearing wet. As grease was leaving past the failed seal, the grease from inside the hub kept the bearing lubricated and there was no damage despite running 100’s of miles with a failed seal. Without the extra grease the bearings would have run dry and the repair much worse. So do they need to be be full? No, but it is extra insurance against a failed seal if they are, and having it happen twice, I’m 100% convinced that this is the method for me.

as you say, tearing them down and greasing them isn’t hard. But then you have to replace the seal again and there is just no need to tear into them if they roll smooth and don’t have any play. Just flush them out and roll the miles. That said replacing the seals every 5 years or so is worthwhile regardless. I’ve not had many seals less than 5 years old fail, but the rest that did were less than 10 years old. So the 5 year mark is a good time to start thinking about pulling them down and replacing the seals just for that reason.

I flushed them out with new grease just before this trip. I did both wheels in about 30 minutes and used less than a tube of grease. So less than $8 and 30 minutes spent just before bedtime in between rain storms. I can’t do bearings and seals that fast, so for me this is a win.




this was my last seal failure. Notice how the inner bearing and seal are stuck to the spindle. Somehow the seal seized to the spindle and the hub was spinning around the seal. When I pulled the hub, things how it came off. Roadside repair was a new seal and fresh grease. This was the one the failed in the rain, but with the hub full of grease the bearings survived. These bearings are still in service and probably have 5,000 miles on them since this happened. So to me, having the hub full is important. Without the extra grease this would likely have ended much differently given the distances driven.

 

Also, for anyone wondering my “thunderer” car tire got me back to rapid city. Put about 500 miles on the car tire at 70 mph to make it back in one day.

not ideal but it survived. It did run slightly warmer than the dedicated trailer tire on the other side but not enough to worry about. It did seem to bounce more on that side of the camper too. I’m thinking that tire was just softer allowing more sidewall flex and bounce. I’m sure it was over its 910 lbs rating but it held up just fine.

I now have two brand new carlstar 145r12 E tires (formerly Carlisle) that will carry me for many more years and adventures. Still surprised and disappointed by the sudden failure of the last ones, but I really do think it was the road they did it.

regardless, we are in good shape for the final 350 mile stretch back home.

 

That was a very comprehensive response, @meborder , and all the more impressive given that you are still traveling on the road.

Moreover, your wheel bearing and tire service while underway is equally impressive. You get it done and keep on going.

I think a lot of readers will appreciate your post and pictures for years to come.

There is one lingering which came first, the chicken or the egg type of question:

While the hub cavity chock full of grease may have saved the wheel bearing when the inner seal failed...

Would the inner seal have failed if the hub cavity were not chock full of grease?

 

great and fair question.

empirically, I say no. If the hub being full was the cause of the seal failure, I’d be having a lot more problems.

the first seal failure was the membrane just ripped. As far as i know, that seal was over 10 years old because I never pulled the hubs, just kept flushing them with the easy lube. Lesson learned.

the second failure defies explanation. What set of circumstances cause the hub to spin around the seal? If you look at that picture you can see the metal interface for the seal is blue from heat. The rubber was perfectly intact, but was somehow stuck to the spindle and the grease was leaking out of the metal/metal interface. Adding to the mystery is the fact that the new seal I installed in the Napa parking lot went in tight and saw 2 years of service before I pulled everything down.

before we went to Utah, I installed new name brand seals and put them in with some sleeve retainer. I may curse myself later for that, but I haven’t pulled the seals since I did. That was in 2023. Cross that bridge in a couple years I suppose.

loosing two tires at once takes the cake so far…. I was only 50% prepared for that.

appreciate the kind words.

 

Regarding the leaking at the hubs.

I had the irritation of the grease on the outside of the wheels. I cured that by putting ultra black gasket sealer on the cap. Been doing that for 10+ years.

I do not use the grease fitting. Repack every 3 years.

 

Here is my take on this. That grease is way to thin to be using for wheel bearings.
Would you use that grease on your DD car / truck wheel bearings and if not why?

I also do not like them "bearing buddy" grease caps as you can pack too much grease into the hub and blow out seals that then coat the brakes and so on.
I use good old wheel bearing grease like on all my cars & trucks wheel bearings, if good for them it is good for the trailer as they are the same type of "wheel" bearings.
On my trailers, mostly car trailers, they get serviced at the beginning of the year and an eye kept on them thru out the year and never had a problem.
Many trips from CT to NJ / MD and out to OH once a year.
Last time I used the trailer it made 3 trips from CT to NC loaded with a car and stuff inside, we were moving, and back up empty all with in 3 weeks.
No problems and that was at 70 MPH and I use light truck tires on it.

If the grease tub dose not say "wheel bearing grease" I will not use it for wheel bearings it is just that simple.
Dave ----

 

It is wheel bearing grease and is recommended for use in disc brake wheel bearings. Says so right in the user data sheet.

https://www.mystiklubes.com/do/product/GREASE/665005002

http://docs.mystiklubes.com/msds_pi/M20026.pdf

It is overkill for this application in every possible metric.Would I use it on a vehicle requiring bearing service? 100% yes.
I’m not using the wrong grease, and the JT6 is far thicker than the valvoline crimson.

https://www.valvolineglobal.com/en/crimson-grease/

the crimson got very thin after several thousand miles.

 

If it works for you then ok, just looks way to thin for my liking and even more so the way it runs / leaks out.
Dave ----

 

In defense of the grease that @meborder reported applying to his trailer wheel bearings most recently... Citgo's Mystik JT-6 Hi-Temp NLGI #2 Lithium Complex Grease is on Dexter Axle's list of Approved Grease Sources, and has been on Dexter's list for quite some time.



There are literally thousands of different brands and types of greases available to choose from, but Dexter only approves 22 of them, for reasons only known to Dexter. Still, 22 different greases leave a light trailer owner with enough variety in brands to choose from to ensure regional availability of a grease approved by the axle manufacturer.

It being established that the world's most foremost light trailer axle manufacturer (and by far the largest, especially since Dexter also owns and manufacturers Alko Axles) approves of Meborder's use of Mystik JT-6 Hi-Temp NGLI #2 to grease trailer wheel bearings... there is no question that Meborder selected an approved grease in the most recent repack reported.

That all being said, I still wouldn't buy Mystik JT-6 Hi-Temp #2, because it is owned by Citgo, which is wholly owned by PDVSA (state owned by Venezuela), which partners with, and is supported and enabled by NIOC (state owned by Iran) in petroleum industry related ventures. I'll leave it at that, as the remaining dots can be connected by reading the news, which ventures off the topic of wheel bearing greases, and has no bearing (pun intended) on the appropriateness of Mystik JT-6 Hi-Temp for the given application in this thread.

Fortunately, Dexter's Approved Grease Sources includes other options. I currently use Shell Gadus S3 V220C #2 Red Lithium Complex, extreme pressure, high temperature, ISO 220, Specification: Meets ASTM D4950-08 GC-LB. Approved by: Aichelin, Dexter Axle, Sør-Norge Aluminium and ***** Vogel. Additional OEM Approval Listings: (Listed by over 20 major companies from a wide variety of industries.)

The Shell Gadus line of greases was formerly named and known as Shell Albida, which explains why Dexter's older 2008 list cites "Albida", while Dexter's newer 2018 list cites "Gadus."

While Dexter approved the most recent grease that Meborder reported using, @FuzzFace2 raises a valuable point to consider. Not all NGLI #2 lithium complex greases are the same. For example, some Ford OEM spec chassis greases contain molybdenum, an additive not found in many of the greases that Dexter approves for wheel bearings. Molybdenum benefits surfaces that slide against each other, like the ***** and sockets of ball joints. We don't want the rollers in roller bearings to slide against their conical cups. That might create flat spots on the roller, and potentially excess wear on the cup. Hence, the Dexter approved wheel bearing greases that I use do not have any molybdenum.

 

Thanks for that Y2K...
Dave ----

 

Here’s the inside of the cap I removed (and just threw away). This is all the extra grease that comes past the front bearing during its first time running. It is anything but excessive IMO.

when I had to do the bearing in the NAPA parking lot when the seal failed somewhere in Wyoming, this was the grease I used. It was what they had on the shelf so I got it. I just packed them by hand and scooped the hub as full as I could and reassembled. Ran it two years with this grease. No problems with it, but it is an aluminum complex not a lithium complex so there could be compatibility issues if you don’t get them 100% clean.

I think the CRC grease is what Dave is talking about. No issues with using it other than I prefer to use the easy lube. I will say, though, the bearings ran 10-15 degrees hotter with the CRC grease than they did with the Mystik or Valvoline. Is it a big deal, not really. But it was measurable and repeatable and consistent.

which grease is better? You decide for you.

interesting take on the Citgo products. That’s stuff I dont normally look into. I may weigh that into future purchases. The Mystik is just what they sell locally at the farm stores, so that’s what I got. Thanks for pointing out the other side of it though. It’s interesting and worth considering.







to the thicker is better part of the conversation, I fall on the other side. Generally for a bearing, the thinner grease will flow better and if it will hold up to the heat of service, that has its advantages. If you are using a super high temperature grease and the bearings never get up into the optimal operating range for that grease, it will never flow and can wear out because it never gets replenished. That was why I initially switched to the crimson. I didn’t need the high temperature grease so I went for just a standard temperature offering. It was definitely thinner and in the heat it definitely flowed more than the high temperature stuff.

but looking back, I’ve not had any of them fail so I don’t think it matters much in practice. So it’s kind of a “use what you like” so long as it’s a #2 grease it will be fine. #1 is not the appropriate spec as it would likely not hold up to the pressure.

something to keep in mind is that oil bath hubs use the exact same bearings but use and extreme pressure oil instead of grease. So it really can’t be too thin so long as it can hold up to the pressure.

 

I'm using Valvoline Full Synthetic Moly-Fortified Gray Grease, which is an NLGI #2 GC-LB lithium complex EP grease. It's NOT on Dexter's list. I think I settled on this grease because it was OK for use in my F-350 and it also has the NLGI #2 feature.

The Valvoline Durablend - that is on the list - appears to be discontinued. The Durablend is Moly-fortified, as is one of the approved greases from ChevronTexaxo.

This is the description of the Valvoline grease I'm using. I'm providing this only to show that they say it's recommended for bearings.

 

That valvoline full synthetic is good stuff. It is one of the few greased that is approved for use in a CV axle.

we used that when we did the rear wheel bearings on my buddy’s c3 corvette. If you know anything about doing rear bearings on that car, you want to use the best grease you can because it is not a trivial task.

I also used it on my CV axle in my Subaru when it lost a boot clamp and slung the grease out. I measured 4 fluid ounces and packed it in the joint before replacing the clamp (twice)

good stuff! I’d use it on the trailers but they don’t get used that hard to require such an expensive grease.

 

The axles on my toy hauler will be close to their weight limit when I go hunting. So I figure the bearings need some TLC.

 

My 5 gal pail of grease is on the list, Texaco Starplex 2. It's much heavier and doesn't leak out of my caps.