Wheel Bearing Greasing - A Modern Perspective

pauldridge

New Member
Joined
Mar 9, 2021
Messages
8
This forum is a wealth of information and I appreciate its existence. That said, I have noticed a common trend for "contributors" who like to pass along rumors/mis-information they have read elsewhere, but have not experienced or observed themselves, and the rumors seem to perpetuate themselves.

Nothing could be more frequent than discussions about wheel bearing maintenance. I respect those who have chosen to remove all 4 wheels and drums, pry out the rear bearing seals, and repack their bearings every few thousands of miles, and who poo-poo the innovative external greasing feature of most all of the axles these days.

But I have to ask.. when was the last time you packed the bearings in your 5,000+ pound Ford truck, in spite of driving 40-50k miles per year? The basic construct of most vehicle bearings is pretty much identical to our trailers.

I almost drank the Koolaid myself regarding rash warnings about using the external grease nipples ("you will blow out the rear seal with too much pressure").

That was before I decided to look at the official company videos from both Lippert and Dexter (not just a video from some shade tree mechanic holding the "camera" in one hand.

If you look at the internal construction of these new hubs, you will see that grease flows through the center of the axle exiting BEHIND the inner bearing, then travels through the bearing along the axle up to the outer bearing, where it comes on through *under gentle grease gun pressure, and finally exists at the front of the bearing and hub.

Here is Dexter's official video describing the greasing process.. Lippert's is near-identical: https://www.youtube.com/watch?v=XT0RKDGgDm8

Yes, both companies DO suggest that you jack up (without removing wheel or drum) and turn the wheel slowly while greasing to assure complete propagation, and continue pumping your gun until you see all the old grease exiting the front and new grease pushing from behind.

So.. I submit a few points based on manufacturer's data, not baseless rumor:
1) No, 2-3 pumps of the grease gun will accomplish virtually nothing. It DOES take a good bit of grease to displace the old grease in both bearings and the internal hub housing.
2) It would be extremely unlikely to "blow" a rear seal, since there is never any significant restriction to the grease's path through both bearings before exiting the front. You could pump a gallon of grease through that bearing, and all you would get would be a huge glob of grease coming out around the outer bearing.

The thing is, systems do improve over the years, in many cases making maintenance chores easy. Just because someone has used "old-school" technigues for the past 20 years doesn't necessary validate that practice with new, improved systems.

Sure, I suppose there is some value in "inspecting" the bearings from time to time, just as you could inspect the same on your tow vehicle, or maybe even your driveshaft bearings, but most people don't, and seem to get along just fine.

For me, I'll just follow the axle manufacturer's guidance (sadly missing from any documentation provided by the trailer manufacturer), spend about 5-10 minutes per wheel, perhaps every 10,000 miles or so, and used the saved time for another margarita!
 
I dont believe you can pack the bearings on modern vehicles, they are typically a sealed bearing.

I still prefer hand packing trailer bearings, uses less grease, but the main reason is so I can also inspect the magnet, brakes and the bearings themselves. If just using the zerk fitting you omit the inspection process which I think is equally important.

Sent from my SM-G950U using Tapatalk
 
Just FYI on my Lippert axle the hole is between the bearings, nowhere for the grease to go toward the inner bearing except out the inner seal.
 
The quality of the Chinese bearings used are not of the best quality. I've replaced all of the OE bearings and races during inspections because I've seen pitting and discolorations (indicating bearing overheating). Additionally without the removal of the hub, there is no way to determine the condition of the magnets, brake pads or if grease has leached beyond the seals. The 2 hours it takes annually to preform this maintenance is well spent as compared to 4 hours alongside the interstate awaiting a tow truck to be dispatched by Good Sam or the like.
 
Thanks for that... always open to learning! I'm hopeful that was an earlier design, and they have modified it as depicted on the supplier's YouTube video as well as a couple of other owner videos I've watched.
There's never one right answer for these issues.. good to have this discussion (again)
 
As you were challenged elsewhere, I will strongly disagree with your statement, "...I have noticed a common trend for "contributors" who like to pass along rumors/mis-information they have read elsewhere, but have not experienced or observed themselves, and the rumors seem to perpetuate themselves." Many of us on this forum have decades of experience with trailers, their suspension systems, and bearings (I've been pulling boats and RVs and doing all the wheel bearing maintenance myself for almost 50 years). You are too quick to paint a number of people with a broad brush and I find it offensive. You are entitled to your opinions - but not to cast aspersions on others.

Rob
 
This forum is a wealth of information and I appreciate its existence. That said, I have noticed a common trend for "contributors" who like to pass along rumors/mis-information they have read elsewhere, but have not experienced or observed themselves, and the rumors seem to perpetuate themselves.

Nothing could be more frequent than discussions about wheel bearing maintenance. I respect those who have chosen to remove all 4 wheels and drums, pry out the rear bearing seals, and repack their bearings every few thousands of miles, and who poo-poo the innovative external greasing feature of most all of the axles these days.

But I have to ask.. when was the last time you packed the bearings in your 5,000+ pound Ford truck, in spite of driving 40-50k miles per year? The basic construct of most vehicle bearings is pretty much identical to our trailers.

I almost drank the Koolaid myself regarding rash warnings about using the external grease nipples ("you will blow out the rear seal with too much pressure").

That was before I decided to look at the official company videos from both Lippert and Dexter (not just a video from some shade tree mechanic holding the "camera" in one hand.

If you look at the internal construction of these new hubs, you will see that grease flows through the center of the axle exiting BEHIND the inner bearing, then travels through the bearing along the axle up to the outer bearing, where it comes on through *under gentle grease gun pressure, and finally exists at the front of the bearing and hub.

Here is Dexter's official video describing the greasing process.. Lippert's is near-identical: https://www.youtube.com/watch?v=XT0RKDGgDm8

Yes, both companies DO suggest that you jack up (without removing wheel or drum) and turn the wheel slowly while greasing to assure complete propagation, and continue pumping your gun until you see all the old grease exiting the front and new grease pushing from behind.

So.. I submit a few points based on manufacturer's data, not baseless rumor:
1) No, 2-3 pumps of the grease gun will accomplish virtually nothing. It DOES take a good bit of grease to displace the old grease in both bearings and the internal hub housing.
2) It would be extremely unlikely to "blow" a rear seal, since there is never any significant restriction to the grease's path through both bearings before exiting the front. You could pump a gallon of grease through that bearing, and all you would get would be a huge glob of grease coming out around the outer bearing.

The thing is, systems do improve over the years, in many cases making maintenance chores easy. Just because someone has used "old-school" technigues for the past 20 years doesn't necessary validate that practice with new, improved systems.

Sure, I suppose there is some value in "inspecting" the bearings from time to time, just as you could inspect the same on your tow vehicle, or maybe even your driveshaft bearings, but most people don't, and seem to get along just fine.

For me, I'll just follow the axle manufacturer's guidance (sadly missing from any documentation provided by the trailer manufacturer), spend about 5-10 minutes per wheel, perhaps every 10,000 miles or so, and used the saved time for another margarita!

While I will agree that a seal in good condition will not allow properly pumped grease to pass...... That is as far as I will go. One does not know the condition of the seals when one just pumps more grease in....they will all fail at some point for one reason or another. And the mess that that is made when it happens will change your mind in a hurry when it happens to you.

And yes I will give you credit for acknoweldging that it takes a good bit of grease to purge all of the old out,,,,,but realize that it takes almost an entire tube..... PER WHEEL!!!
That gets kind of pricey. I also agree that one should be able to go much longer between repacks.

So to sum it up: Unless you have xray vision, you cannot tell if the grease you are pumping is getting past the seal or not. So it is just a leap of faith to trust it isn't.

Now since I have disc brakes, I could safely use this system.... But I do not think I will. With a triple axle that would mean 6 tubes of grease. I think I am going to use that money towards oil bath hubs.
 
Op, sorry, but it is really clear that you have not worked on heavy trucks nor trailers. Plenty of tribal knowledge here but also a ton of expertise from all walks of life, and plenty of us who have been in this hobby, hands on for decades. I appreciate book learning, but I also believe in the mantra of my alma mater - learn by DUing. So, heavy duty axle bearing are lubricated by the gear oil, which is integral to full floater design. Heavy trailer axles are as well. 8K axles it's optional but standard 10K and up. There's real reason behind it too. Unfortunately the RV community evolved out of its own and the grossly devolved after Lippert gobbled every quality frame builder.

There is also absolutely nothing modern about the suspensions used on any factory GD and majority of mass produced camper trailers.
 
Last edited:
but the main reason is so I can also inspect the magnet, brakes and the bearings themselves. If just using the zerk fitting you omit the inspection process which I think is equally important.

Sent from my SM-G950U using Tapatalk

^^^ This ^^^^
 
Anytime I have no experience with taking care of a piece of machinery I always default to the manufacturer. They did actually design and build the thing. I trust their judgment over the thousands of internet mechanics out there. I’m not minimizing the years upon years of experience but they did design and build it. His thread is about modern trailers. And if your trailer has that feature why not use it? Did your trailer have that feature 50 years ago? Maybe it did maybe it didn’t, but like the telephone 50 years ago metals, alloys, grease, engineering, and designs have changed. So I pause before I hear anyone talk about their years of experience. I don’t discredit it, I simply go to the source of the product. The people who make it, and if you call and actually speak with their team you will learn about how there product can do this. And btw I have zero experience taking care of bearings in a trailer, so it’s my learning hobby which is a lot of fun. And learning how anyone makes a modern piece of engineering is very fun. So if I blow my seals, first call will be the dexter. Add it to the thousands of things I have learned with this hobby.


Sent from my iPhone using Tapatalk
 
Anytime I have no experience with taking care of a piece of machinery I always default to the manufacturer. They did actually design and build the thing. I trust their judgment ...

This would normally be good advice. I'll bet if you ask any of us that were affected by greased brakes, we would completely disagree with you. In the earlier GD models LCI pumped grease into their new axles and used a grease that was on the runny side. As a result of this grease DID get past that inner seal and contaminated the brake pads. Once grease is on the pads, the brakes are toast, you cant just wipe the grease off. Half the wheels on my Momentum had contaminated brakes. LCI sent me 6 new brake assemblies and seals at no charge. There are numerous discussions on this forum about this very issue. The "internet mechanics" on this forum have decades of experience and seeing how the design of our suspension system is also decades old, I would definitely listen to what they have to say.

Sent from my SM-G950U using Tapatalk
 
Anytime I have no experience with taking care of a piece of machinery I always default to the manufacturer. They did actually design and build the thing. I trust their judgment over the thousands of internet mechanics out there. I’m not minimizing the years upon years of experience but they did design and build it. His thread is about modern trailers. And if your trailer has that feature why not use it? Did your trailer have that feature 50 years ago? Maybe it did maybe it didn’t, but like the telephone 50 years ago metals, alloys, grease, engineering, and designs have changed. So I pause before I hear anyone talk about their years of experience. I don’t discredit it, I simply go to the source of the product. The people who make it, and if you call and actually speak with their team you will learn about how there product can do this. And btw I have zero experience taking care of bearings in a trailer, so it’s my learning hobby which is a lot of fun. And learning how anyone makes a modern piece of engineering is very fun. So if I blow my seals, first call will be the dexter. Add it to the thousands of things I have learned with this hobby.


Sent from my iPhone using Tapatalk

Normally, sage advice - completely agree... However, being an engineer, I can also tell you there is REGULAR disconnect from the designers versus those writing the operations and maintenance manuals... When I studied undergrad, required engineering curriculum included technical writing just for the purpose of writing proper instructions. I haven't seen such in a required curriculum in decades. Moreover, if you know the evolution of Dexter and Lippert, you'd quickly come to understand they did not design, for the overall majority, the axle assemblies used on camper trailers. Lippert tried to value engineer proven designs, and that failed miserably, and both have taken a lot of cost out of them to detriment of the product. Primary case would be to compare the standard seal of 20 years ago to what you see as meeting manufacturing spec today... On one hand, I respect you wanting to learn via your own knocks. On the other, trying to stop a 5er running down a 6%+ decline with greased over shoes is folly when literally countless members of ALL camping trailer communities have reported the problem, manufacturers are aware of the problem, and there's standard of care and conscience... Unfortunately, in manufacturing, there is acceptable failure rate, and that is the real, modern world.
 
If this really was as big of problem as you all say then why has it not been fixed? Can you all make name any component design that could cause a lose of braking in any component in moderna transportation for decades that would have not been address either through the company regulation or litigation. This is all I’m saying, do you all really know of now this a problem?


Sent from my iPhone using Tapatalk
 
If this really was as big of problem as you all say then why has it not been fixed? Can you all make name any component design that could cause a lose of braking in any component in moderna transportation for decades that would have not been address either through the company regulation or litigation. This is all I’m saying, do you all really know of now this a problem?


Sent from my iPhone using Tapatalk
LCI has changed the type of grease and if i recall the method of installing the grease in new axles. My original point was that you shouldn't blindly trust a manufacturer just because they are the ones who designed and manufactured something. This cant really be a new concept to you if you have any experience with RVs. RVs are notorious for needing work done on brand new ones either by owner or a repair center. It is not even close to the same standard as the auto industry.

Sent from my SM-G950U using Tapatalk
 
I repacked my axles last week on my 2019 2800bh for the first time. I did grease my axles one time using the ez lube system midway through 2019. The camper was only used twice in 2020.

I was not ever worried about my hubs and bearings....until I saw them! Half of them showed evidence of excess heat and one of them had a slight groove in the race. Also, why in the world would GD use a bearing made in China on all 4 outer bearings but a Timkin bearing on all 4 inner bearings?

The good news is that the rear seal and brakes were all in great shape.
 
Isn’t the only way to get the centre cap off to grease is to remove the wheel anyway??


2021 Imagine 2400 BH
2018 GMC Sierra 4x4 crew
 
A different perspective, with all due respect to [MENTION=26275]geotex1[/MENTION] I have a degree in automotive technology, have been an ASE Certified Master Medium/Heavy Duty mechanic for decades, and have been working in fleet maintenance (Air Force, public transit, school district) for the past 45 years. There have been more times than I can count where I've been "What in the H-E-double hockey sticks was this engineer thinking!" He couldn't possibly think that was going to work... With countless Service Bulletins, Recalls, etc. across all types of equipment it's obvious the engineers aren't always right. I don't default to manufacturers instructions (although they are the starting point), I default to industry proven "Best Practices". In all my experiece, THE most important aspect of automotive care is Preventive Maintenance! The objective here is to make a best attempt to spot minor issues before they become major and costly repairs. Having said all that, wheel maintenance is one of those simple tasks that, if not done dilligently, will leave you on the side of the road. I can't stress this enough... disassemble, clean, inspect, replace as necessary, re-assemble. By the time you realize the seal failed, it's too late and hopefully it's not at the bottom of a long down grade. By the time a bearing fails and your wheel goes bye-bye, it's too late. Costly and potentially dangerous. JMHO

John
 

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top Bottom