My TT axles have the EZ lube spindles with the grease fitting on the end. It's time for me to repack the bearings. Is it safe to hand pump new grease through the fitting while slowly turning the wheel, or do I need to remove, clean, and repack the bearings by hand? If so, what's the purpose of the grease fitting on the spindle? I bought my camper brand new a little over a year ago. Thanks.

My take: every one says to repack the bearings by hand but, I have had two trailers (each one seven years), with the easy lube bearings. I did it once a year using a grease gun. I would jack the wheel and as I was pumping the grease, I would turn the wheel. Once I saw the old grease coming out, and saw the new stuff right behind it I would stop. I never had a problem and put thousands of miles on both trailers. On the second one, I had them repacked by a shop in it's sixth year, and the mechanic said that the bearings were in good shape.Jack l

plasticmaster wrote:My TT axles have the EZ lube spindles with the grease fitting on the end. It's time for me to repack the bearings. Is it safe to hand pump new grease through the fitting while slowly turning the wheel, or do I need to remove, clean, and repack the bearings by hand? If so, what's the purpose of the grease fitting on the spindle? I bought my camper brand new a little over a year ago. Thanks.IMHO, the bearing grease fittings are a waste of money, useless in actually properly greasing your bearings, and in fact, could cause a major problem inside the brake drum should the grease get pushed out past the seal. The "bearing buddy" type of bearing greaser is more designed for trailers that do not have braking systems and are subject to being submerged in water (i.e. boat or jetski trailers). When the trailer is run into the water, water can seep in past the wheel seal and get into the bearing area. This will cause rusting and possible bearing failure. These greasing systems were designed to allow the owner to inject grease into the bearings and hub to possibly flush out the water. If there is no air space inside the bearing/hub area then no water can get inside.On a travel trailer, you do not have the problem with water intrusion (or if you do, you need to stop parking your trailer in a lake, stream or river). They put these greasing systems on travel trailers because basically (and by mo means am I accusing you of this) people are lazy and don't want to have to either take the trailer in for service or spend the couple of hours needed to do bearing maintenance. They are told to just pump a few shots of grease into the grease zerk, and away you go. Problem, the grease does not fill the cavity inside the hub, so only the outer bearing gets some of the grease. The inner bearing gets little or nothing. Another problem to look at is that some think that if a few squirts of grease are good, then a LOT of them should be great! Eventually, you will reach the point where the entire cavity is full of grease. Then the grease has no place to go. As it doesn't compress (at least not under the pressures you are subjecting it to) it has to go someplace. Out the back through the space between the Spindle and the grease seal is the weak link.Once the grease gets past the seal, it is now inside the brake drum. And as that grease gets slung around the inside of the drum, it makes your brakes ineffective and possibly cause a fire due to the grease getting too hot from the friction inside.So, after that dissertation on greasing your bearings...Short answer, pull the bearings, clean and inspect them, regrease with good grease, and put them back together. Your peace of mind in knowing that everything is good to go will take one less worry off your mind as you are heading down the road.

Although we have the same option on our axles I still do them the old fashion way, I feel better that I had a chance to see the wear and tear for myself. Good news is that if they are properly done, wheel bearing service will last several years before a full cleaning and repacking is required. Nothing wrong with doing it yearly but with top notch, high-temp grease I find it isn't required annually for our heavily used TT. They are rarely exposed to harsh elements where we RV most. Every Spring after de-winterizing our rig I take all wheels off and inspect brakes and bearings, I'm on our 4th camping season since the last wheel bearing service and all still looks great. Although I never tried, I would believe the Easy lube option works for many but there have been a plethora of reports where seals were blown out allowing grease to reach brakes. It's good that your are checking bearings as sometimes they leave factory improperly greased.

Really bad advice from Bager The easy lube system is a good system It uses a double lip seal on the axle shaft to prevent grease from entering the brake area. When you grease through the zerk the grease goes through the center of spindle and out a small hole just beyond the inner bearing and before the seal. As you slowly grease and turn wheel the grease is forced through the innner and outer bearing and you will see it coming back at you around the spindle , zerk area then stop . The key thing here is pump slowly and turn the wheel also when pumping . The first time it may require a half tube of grease or more .

Really good advice, badger. The problem with your response is that the subject is not about the Bearing Buddy system, it is about the useless grease fitting installed in the spindle.

EZ lube spindle and bearing repack question | Good Sam Community

83 Replies

RinconVTR
Explorer
Jul 14, 2017
mike-s wrote:
rjxj wrote:
The grease has RESISTANCE to flow
Why bother? It's obvious rjxj doesn't understand even grade school science. Or maybe he's just trolling - it's hard to believe someone who can write is that ignorant.

He's actually spot on and describing the situation in more detail than I was all with hopes something would click with you guys.

Look, no one will twist your arm to use the EZlube zerk, so I'm really puzzled why you continue to throw down your flat out lies and inaccurate statements. They are not even alternative facts...they are just wrong.

Those who claim it can blow a seal IMO have never purposely or accidentally done so (on a good seal) to find out how much manual grease gun pressure it actually requires to do so. And likely have not removed and installed axle seals to find how tightly they are pressed in and how robust the seal to metal bond really is. Try to destroy one...just try it. Axle seals are VERY robust and not easy to "blow out" unless worn and the press fit is no longer a press fit!
RinconVTR
Explorer
Jul 14, 2017
My own pics from the last seal replacement;

Look at all that grease flying out at high pressure...
Huntindog
Explorer
Jul 14, 2017
wnjj wrote:
Huntindog wrote:
Some grease gun facts:
Grease guns develop pressure in the grease, that is what causes it to move. No pressure = no grease movement. Grease guns are capable of 10,000 PSI!!! In fact the lowest one I can find develops 3500 PSI!! With a grease seal able to hold back only 10 PSI, there is an obvious mismatch. It is easy to see how a grease seal can be overpowered by a grease gun pressurizing the grease.
And on a related note, I saw ratings from 33 to 56 strokes per oz. of grease! So if a hub takes 1/2 a tube of grease (7 oz) to fill it, that could mean 231 to 392 pumps for ONE hub!!

Grease does take pressure to move and grease guns can make lots of pressure, however the pressure in the system is limited to the lowest exit point. If moving the grease through the bearings to the open air surrounding the fitting takes a lower pressure than the rear seal can hold it works just fine. How much pressure the grease gun can generate is irrelevant in an open system.
Oh the grease WILL be pressurized. There IS resistance to the grease movement as it goes thru the system. If you have ever hand packed bearings, you will have experienced this pressure. You gotta force the grease into the bearing, it doesn't just fall into them willingly. With the EZ lube your are effectively packing two bearings at once. So twice the resistance. and then there is the added resistance of the grease flowing thru the passage ways and the hub.. This resistance will hardly be felt by someone using a grease gun developing 3500 to 10,000 PSI. But it CAN easily over power the seal. That is why Dexter cautions about pumping SLOWLY.... Of course they do not mention how many SLOW PUMPS it will take for a complete grease change. (231 to 392 per hub MINIMUM) That will take a long time and use a LOT of grease.
The only thing you are correct about is that the opening to the outside of the spindle adds little to no resistance.
wnjj
Explorer II
Jul 14, 2017
Huntindog wrote:
Some grease gun facts:
Grease guns develop pressure in the grease, that is what causes it to move. No pressure = no grease movement. Grease guns are capable of 10,000 PSI!!! In fact the lowest one I can find develops 3500 PSI!! With a grease seal able to hold back only 10 PSI, there is an obvious mismatch. It is easy to see how a grease seal can be overpowered by a grease gun pressurizing the grease.
And on a related note, I saw ratings from 33 to 56 strokes per oz. of grease! So if a hub takes 1/2 a tube of grease (7 oz) to fill it, that could mean 231 to 392 pumps for ONE hub!!

Grease does take pressure to move and grease guns can make lots of pressure, however the pressure in the system is limited to the lowest exit point. If moving the grease through the bearings to the open air surrounding the fitting takes a lower pressure than the rear seal can hold it works just fine. How much pressure the grease gun can generate is irrelevant in an open system.
rbpru
Explorer II
Jul 14, 2017
Well I believe once again we are down to "How many angles can dance on the head of a pin" that is everyone is saying what they believe is the best solution.

Which is better, to have an inexperienced individual disassembling the wheel hub, manipulating around the brake magnet, replacing the rear seal, removing he bearings, cleaning the old grease from the bearings, re-greasing both bearing, re-assembling the hub assembly, properly installing the castle nut and cotter pin; or slowly rotating the wheel while carefully pumping in grease until clean grease comes out of the bearing.

The truth is there is no correct answer because the question is specific to the skills of the individual.

Personally, I prefer the disassembly method but I grew up with that technology. others have not. I also do not have a high confidence level in the TT repair folks, but that is my personal bias.

EZ hubs do what they are intended to do, shove new grease to the back bearing and take the previous grease that has been has been coating the hub spindle and use it to replace the grease in the front bearing. You can of course keep pumping until you have replaced all the previous grease.

Which of these methods would you give to a mechanically inclined 10 or 12 year old? I my case I would sit down and show them how to do the disassembly, some folks are not so lucky.
Huntindog
Explorer
Jul 14, 2017
Some grease gun facts:
Grease guns develop pressure in the grease, that is what causes it to move. No pressure = no grease movement. Grease guns are capable of 10,000 PSI!!! In fact the lowest one I can find develops 3500 PSI!! With a grease seal able to hold back only 10 PSI, there is an obvious mismatch. It is easy to see how a grease seal can be overpowered by a grease gun pressurizing the grease.
And on a related note, I saw ratings from 33 to 56 strokes per oz. of grease! So if a hub takes 1/2 a tube of grease (7 oz) to fill it, that could mean 231 to 392 pumps for ONE hub!!
azrving
Explorer
Jul 14, 2017
RinconVTR wrote:
mike-s wrote:
RinconVTR wrote:
The EZlube system is NEVER under pressure at any point in time...ever. As in, never ever...ever. Did I mention never?
If you think that, you're out of the discussion for ignorance. If there's no pressure, by what supernatural magic do you think grease gets pushed through the bearings?

With the rubber cap off, the hub has a huge open void that does not allow any pressure to build. That simple.

Being completely seriousness, I think you need help.

Good drawing. The grease has RESISTANCE to flow because of it's viscosity so if the seal lip contact with the shaft is not good enough it will follow the path of least resistance like water and take the short path and flow past the poor seal. There is FORCE to move the grease to wherever it may flow but the area isn't under pressure. Pressure equals force x area. You cant put a pressure gauge anywhere in the cavity and build pressure. It will always move the grease. If the grease cant be moved with out it going past the seal then the seal isn't doing it's job.

The seal surface has to have the proper finish for the seal to break in. A new seal shouldn't be riding on an old "path". The seal cant be installed crooked in the bore.

It's not a flaw in the design just because ez lube proves that the sealing is poor. So should they have designed and installed ez lube on all these axles.....well maybe not. Could the sealing be pee poor from the day it's new? Well...it is an RV :)
RinconVTR
Explorer
Jul 14, 2017
mike-s wrote:
RinconVTR wrote:
The EZlube system is NEVER under pressure at any point in time...ever. As in, never ever...ever. Did I mention never?
If you think that, you're out of the discussion for ignorance. If there's no pressure, by what supernatural magic do you think grease gets pushed through the bearings?

With the rubber cap off, the hub has a huge open void that does not allow any pressure to build. That simple.

Being completely seriousness, I think you need help.
mike-s
Explorer
Jul 14, 2017
RinconVTR wrote:
The EZlube system is NEVER under pressure at any point in time...ever. As in, never ever...ever. Did I mention never?
If you think that, you're out of the discussion for ignorance. If there's no pressure, by what supernatural magic do you think grease gets pushed through the bearings?
RinconVTR
Explorer
Jul 14, 2017
mike-s wrote:
Mont G&J wrote:
why doesn’t the axle manufacturers use seals like those on every car and truck rear axle that work just fine in keeping the gear fluid from leaking
Those systems aren't pressurized like an EZ-Lube hub is when pumping grease in. And, the axle seals work just fine if you hand pack the bearings so the seal doesn't experience that pressure. Next question.

Come on...lets get past at least one major point. The EZlube system is NEVER under pressure at any point in time...ever. As in, never ever...ever. Did I mention never?

Car and trucks with drum brakes did in fact have roller bearings back in the day with seals that did fail. Dont be fooled.

And the same grease seals used with the EZlube are used on oil bath systems? There is no such thing as a "EZlube seal. There are multiple manufactures of the axle seals all trailers out there can utilize.

Today, the majority of vehicle axles use closed and seal bearings that can last hundreds of thousands of miles. Did you know you can add permanently sealed bearings to most large trailer axles? It's an option, just like going all disc brakes and ridding crappy drums.

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EZ lube spindle and bearing repack question

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