Repacking wheel bearings

[Biggjb]

I am new to MOC as I just purchased a 2009 2980RL. My wife and I just love it. As we do not expect to put too many miles on it and Keystone recommended repacking interval is 12 months or 12,000 miles. As I expect to put on way less than 12,000 miles a year is it advisable to perform the repacking job at the mileage interval rather than the yearly? Also, is this something I can do, as it does not seem to difficult?

Greg

[ols1932]

First, welcome to the MOC. You've come to the right place to have your questions answered. You may like the answers and you may not. One has to remember that everyone has an opinion and we all can only give our opinion. I like to work from my experiences rather than opinion. So I'll tell you what I do. I have my wheel bearings packed yearly because we travel full time. At that time I also have the brake linings checked and replaced if necessary. If not necessary to replace, the least I have3 done is to have the brakes adjusted after repacking the wheels is complete. It is something that anyone who is handy can do. I quit doing it because of physical limitations (and age). I think that you can get by maybe just inspecting your wheel bearings once a year like in the beginning of the travel season. But don't take that as gospel.

Orv

[noneck]

Yes...welcome...I too do my own wheel bearings & brake work. As a part-timer I did them every year then moved to every other year and now back to once a year. They have been no different in appearance with either frequency but I tend to worry about stuff now figure its good therapy. My reasoning falls on the when on vacation is it worth spending my time on side of road or at destination under my awning...

[Tom S.]

Your trailer should have the Easy Lube system. To find out for sure, remove the rubber dust cover in the center of the wheel and see if there is a grease fitting behind it. If there is, you have it. You can lube the bearings using that grease fittings. Grease goes in the fitting, travels to the back of the axle and comes out behind the rear (inner) bearing. From there, it forces its way through the bearing and travels outward toward the front (outer) bearing. When you see grease coming out the front bearing, you know everything is lubed.

Here is were there seems to be some difference of opinions on the use of this system. Some folks think one or two pumps is all you need. That is true IF the system is full of grease. Ours was not and it took many many pumps before the axle was full enough to force grease through both bearings. Once that was accomplished, the system works very well.

The alternative is to remove the wheel/hub and do it manually. To do it properly, you remove the old grease and repack the bearings with new. You can do this by hand or buy a neat gadget that you set the bearing on and use a grease gun to pump in fresh grease. If you use this gadget, you do not have to remove the old grease from the bearing as the new grease will force it out.

For what it's worth, I prefer to do this myself, like many maintenance items such as changing oil, etc. The reason is two fold. While doing these types of things, you can check wear items and look for potential problems. An example of this would be to check your brakes for wear and adjust them while doing the bearing lube. The second reason, to be frank, I don't completely trust a stranger to do the job right unless I'm there to watch. That's not to mention you can save a lot of money if you do it yourself!

[H. John Kohl]

All are great answers.


Tom S. Mentioned the EZ Lube. One comment on that. Do not use an air compressor grease gun if using the EZ Lube. The rear seal is a weak link and if the grease comes in at too high a pressure it will blow past the rear seal and put grease on the brake shoes. I have used a hand gun with slow pumps and turn the wheel while applying grease.


I like the idea of pulling the wheels every year inspecting the brakes, check the wires for the magnet, adjust the brakes and get a good feel on the grease level. Be careful when jacking the trailer to pull the wheels.


Great question and welcome to the forum.

[8.1al]

I have had 2 trailers with EZ lube and very carefully hand pumped while rotating the tire. I had to replace the brakes on both of them because of grease on them. I have worked on machinery for many years and generally speaking the last thing you want to do is fill a cavity with grease and when you use the EZlube you do just that. All that grease adds drag and creates heat. When you have heat you create pressure in the cavity and where does it go? Hopefully out the plug over the grease zerk and not out the seal, but it seems it chose the seal on my trailers.

[Tom S.]

John hit a good point. I actually don't like to use a air grease gun on anything. Unless you are careful, it's too easy to blow out a seal, and that goes for ball joints, tie rods, etc. It might be good if oil changes and grease jobs were all you did for a living to help avoid carpel-tunnel, but I only use a grease gun a few times a year, so I stay with the manual one.

[sgtpp214]

Welcome to MOC, the best RV site around. I worked in a full service gas station when in college many moons ago. I don't do any of my vehicle maintenance anymore. WE are considered parttimers, RVing about 8 months a year and I have the Monty's wheel bearing repacked every July and the brakes inspected.

[Biggjb]

Thanks to erveryone for your advice. As Tom S mentioned, I do have the Ez lube system. However, as my 5th wheel was a showroom model I would assume it was never taken out and the wheel bearings were packed at the factory. Knowing this, would I also assume they were packed completely. By this I mean the cavity between the inner and outer bearings?

I pumped about 3 or 4 pumps of grease in each wheel and no grease came out. Would this mean the cavaity is not full and therefore perhaps I should put in more grease.

[noneck]

Right...I have that system too, but feel my rig is not gonna be running down a boat ramp. That system will require full cavity before it can push grease forward to front bearing and to make that happen pressure gets put against the rear seal which if it does not contain then you end up with grease in the brake shoe space....therefore I do not use the zerks.

[kdeiss]

I have been told by two Rv Tech's one pump and one pump only. A hand pump grease gun can blow out a seal I have been told 500 PSI will do it. A hand pump grease gun's are 2500 PSI or more.
I have repacked 3 times in 6 years and one pump every year.I am not a full timer

[clutch]

We put around 2500 miles a year on our trailer. The bearings get packed every three or four years. I also have the ez lub axles and I don't ever pump grease into them.

[Tom S.]

quote:Originally posted by Biggjb

Thanks to erveryone for your advice. As Tom S mentioned, I do have the Ez lube system. However, as my 5th wheel was a showroom model I would assume it was never taken out and the wheel bearings were packed at the factory. Knowing this, would I also assume they were packed completely. By this I mean the cavity between the inner and outer bearings?

I pumped about 3 or 4 pumps of grease in each wheel and no grease came out. Would this mean the cavaity is not full and therefore perhaps I should put in more grease.

That is exactly what it means. I went through over a tube of grease to get all mine 'filled'. It's too bad they couldn't have put some kind of plastic spacer with holes between the rear and front bearing to take up the space so you don't waste so much grease.

[Tom S.]

quote:Originally posted by kdeiss

I have been told by two Rv Tech's one pump and one pump only. A hand pump grease gun can blow out a seal I have been told 500 PSI will do it. A hand pump grease gun's are 2500 PSI or more.
I have repacked 3 times in 6 years and one pump every year.I am not a full timer

That's fine, but if you do what they recommend, you are only doing the rear bearings. Of course those RV techs will be happy to replace those front bearings when they wear out.

The second post of this link has an excellent picture of how this system works: http://www.montanaowners.com/forums/...bearing,grease

[kdeiss]

I trust My RV tech' one was the dealer the other has been working on my RV's for over 20 years bottom line no problem

[8e3k0]

With any high speed rotating device like wheel bearings, you never fill the space between the bearings with grease! As higher temperatures escalate, expansion takes place with grease, and there is only one place for it to go, and that is out the rear seal and into your hub.
In Industry and with their standards, all out rotating equipment had any grease zerks removed and even if they did remain, we did not allow anyone with a grease gun near these bearings. They were serviced once per year after about 8500 hours of continuous high speed rotation. We never had a bearing failure in some of the most extreme service applications. Each to his own, if it makes one feel good to pump that cavity full of grease, it may be okay but the excess does no lubrication whatsoever. Its like greaseable front end parts on the older autos, many service tecks were not happy until the seal was blown with over greasing. This should create a lot of discussion; and maybe the Easy Lube systems do have an expanable cavity in the hub for heat and expansion. From what I see on any drawings the hub area is filled with grease, quite a waste. Be nice to hear some of their Engineering advantages for building this type of hub. Trucks and cars complete 100,000 miles and multiple years with no front wheel bearing problems, why are we over grearsing our RV bearings? Is it because of weight??

[PapaBeav]

I took my rig into a local repair shop that specializes in brakes and bearings for trucks and rv's for a bent axle earlier this year. And while I had it in there I had him repack the bearings and check the brakes. I talked to him about repacking the bearings for future reference in case I wanted to do it myself. He told me to just pack the bearings, but do not fill the cavity. Also I asked him if it was necessary to do it every year, and he stated that every two years was sufficient.

Rich

[Tom S.]

quote:Originally posted by 8e3k0

With any high speed rotating device like wheel bearings, you never fill the space between the bearings with grease! As higher temperatures escalate, expansion takes place with grease, and there is only one place for it to go, and that is out the rear seal and into your hub.
In Industry and with their standards, all out rotating equipment had any grease zerks removed and even if they did remain, we did not allow anyone with a grease gun near these bearings. They were serviced once per year after about 8500 hours of continuous high speed rotation. We never had a bearing failure in some of the most extreme service applications. Each to his own, if it makes one feel good to pump that cavity full of grease, it may be okay but the excess does no lubrication whatsoever. Its like greaseable front end parts on the older autos, many service tecks were not happy until the seal was blown with over greasing. This should create a lot of discussion; and maybe the Easy Lube systems do have an expanable cavity in the hub for heat and expansion. From what I see on any drawings the hub area is filled with grease, quite a waste. Be nice to hear some of their Engineering advantages for building this type of hub. Trucks and cars complete 100,000 miles and multiple years with no front wheel bearing problems, why are we over grearsing our RV bearings? Is it because of weight??

On a sealed system I would agree 100%, but this system is not sealed. There is a rear seal to keep the grease off the brakes, but there is no front seal. If you take off a wheel, you will see what I mean - you are looking at the front bearings! So any heat expansion would just push the grease out the front.

With regard to the bearings, it may be as you suggest the weight, or maybe the bearings themselves could be improved (read made heavier duty!). I do know that even the sealed bearing on cars have problems. I had to replace my work truck bearings (an S-10) at 75,000 and I've read numerous reports about the front bearings on GM front bearings over at DeiselPlace.com. So I guess nothing's perfect.

[Tom S.]

quote:Originally posted by PapaBeav

I took my rig into a local repair shop that specializes in brakes and bearings for trucks and rv's for a bent axle earlier this year. And while I had it in there I had him repack the bearings and check the brakes. I talked to him about repacking the bearings for future reference in case I wanted to do it myself. He told me to just pack the bearings, but do not fill the cavity. Also I asked him if it was necessary to do it every year, and he stated that every two years was sufficient.

Rich

It really depends on your mileage. Also, for what it's worth, synthetic grease doesn't separate when heated like standard grease does, so I'd be willing to bet you could let it go even longer.

[8e3k0]

The actual hub cap in any wheel bearing application is the seal (threaded or press fit) and will sometimes hold more than that rear seal mainly do to area displacement. I have blown the inner seal on a Agriculture plow wheel bearing yet that cap remained snug and in place; other times, yes you can blow the cap off by over greasing if the zerk is on the hub of the wheel. In these applications the rotational speed is low (no heat). On an average RV the wheel rotation at 60 mph would equal about 650 revs per minute which is quite slow compared to 1800 to 3600 rpm in a lot of bearing applications. So on RVs with the right amount of grease and proper bearing adjustment the repacks likely do not need to be completed at a high frequency as noted above.