Wheel Bearing Repacking Or Replacement
Here's a quick how-to on repacking or replacing the wheel bearings used on your
trailer . The job isn’t difficult but it is messy so
it’s best to have rags and hand cleaner before you begin.
Tools:
You are going to need some common tools to do this job. There are no special tools required though and its likely that you may already have all that youll need. You'll need a jack of course to get the trailers wheels off of the ground. I prefer a hydraulic jack. You'll need a lug wrench to fit the nuts on your trailer's wheels - a 4-way lug wrench is an inexpensive tool if you dont already have one. For hand tools you're going to need a ball-peen hammer, one of about 14-16 oz. (that's how hammers sizes are designated, by the effective weight of the head) is a good size. A small wooden block is very handy, just cut off about four to six inches from the end of a 2x4 and you'll be set. You're going to need a pair of channel-lock pliers and a medium sized (10 inch) adjustable wrench too. If you are putting in new bearings you're going to need a drift, which is simply a section of metal rod that you will use to remove old bearing races. A brass one is good. It will be good to also have a steel drift or punch. I use other make shift tools too, things like an old cold-cut chisel and small sections of water pipe but none of this stuff is really necessary. As you'll find out for yourself some of the things you are getting ready to do will require just a bit of improvising on your part.
Jack It Up Safely:
The first thing you need to do is chock the wheels of your trailer on the side you are not working on. You don't want that trailer moving at all and giving it a chance to fall off your jack stand. So go ahead and chock one side's set of wheels and then come back to the side you're going to start on. It has been suggested to me, and I think this is a very good idea, that you can effectively chock the wheels by simply hooking the trailer up to the tow vehicle. That way you use the tow vehicle's parking brake (and the "Park" position on the transmission if its an automatic) to make sure the vehicle and trailer cant move and fall. Don't, however, let this lull you into thinking it is safe to support the trailer with just the jack. Get a set of jack stands; they're inexpensive enough to be affordable by most anyone and ever so much less expensive than any visit to an Emergency Room. Under no circumstance at all should you put one single part of your anatomy under any part of a trailer when it is jacked up, with one or more wheels off the ground, unless you have a jack-stand under it.
Remove the Wheel:
It is not, as you might imagine, necessary to remove the wheel from your trailer to do this job but its Oh so much easier if you do. So let's remove the wheel. Begin by loosening the lug nuts loose on the wheel(s) on the side you will start on. Just loosen them, do not remove them before the wheel is off of the ground. Now jack up the trailer and get a jack stand under it once the wheel(s) are off the ground. Don't jack it up as high as possible, just get the wheel a bit off the ground - there's no reason to have to lift the tire and wheel up any higher than you have to when its time to put it back on. Now that you have the wheel off the ground remove the lug nuts and take the wheel off. The reason you broke the nuts loose before you jacked up the trailer is that the torque you would apply to the nuts in breaking them loose would tend to spin the wheel. Its almost impossible to break lug nuts loose on a wheel that is off the ground.
How Bad Were The Old Bearings?
You’ve now got the trailer is up on the jack stand and you've just removed the wheel. This should leave you looking at the hub or possibly a brake-drum/hub combination or possibly a disk brake assembly. The procedure for the bearings is the same no matter which it is. This is a good a time as any to satisfy your curiosity about the condition of your bearings the hub should spin easily by hand and without any undue noise - in fact almost no noise at all unless its a brake-drum/hub in which case you will hear the brakes rubbing slightly. The hub should not rock on the axle excessively but there may be some end play moving in and out from the trailer's center if you pull on it (remember those jack stands?). The play in the wheel shouldn't be over about an eighth of an inch and actually shouldn't be that much.
Remove The Grease Cap Or Bearing Protector:
First you have to remove the existing grease cap or bearing protector, whichever your hubs have. You can sometimes remove these by grabbing them from the outside with a pair of channel-locks and rocking and pulling. If they are the stock stamped sheet metal stock caps you can sometimes get something in there (I use a large screwdriver) in between the stamped ridge of the cap is against the hub and do some prying to get it moving. More often than being able to move it with channel-locks you will have to take a ball-peen hammer and tap glancing blows onto the edge of the cap and get it coming off that way. Once its been loosened up some you can almost always pull it the rest of the way off with the channel-locks. With the grease cap removed you will be looking at the axle nut (though it will be grease covered).
What Is All This Stuff?:
Let's see what is in there. Moving from the outside to the insides here's what you find: The whole bearing assembly and the hub itself are held in place by one large nut. The nut is held from loosening by either a retainer (sort of a washer like device with tabs on it, one of which will be bent to contact the nut and hold it from turning) or a cotter pin. Cotter pins are the most common method of securing the nut. The nut will be followed by a large washer, called a thrust washer, on most assemblys, Then comes the outer bearing (the one farthest Out from the trailer's centerline of the trailer) then a void, and then the Inner (and usually larger) bearing. Finally pressed into the back of the hub you'll find the grease seal.
Let's Tear It Apart!
To begin this job we're going to start by removing the axle nut. Wipe off the grease from the end of the axle and you'll see the nut and its retaining device. If its a cotter pin just straighten it and pull it out. If its hard to remove put the tip of a pair of needle-nosed pliers through the end loop of the pin and then tap on the pliers with your ball peen to pull it out. If its a tab type retainer bend back the tab that is holding the nut in place. Using the adjustable wrench remove the nut. Notice that the nut was not particularly tight. In fact it should have been loose enough that you might be able to remove it by hand. Thats good. When you put it all back together you aren't going to be putting that nut back on very tightly either - just sort of keep that in mind.
As you remove the nut you'll notice that the hub is now able to move in and out on the axle. Remember when you checked for play before removing the nut? If you were just checking your wheels for excessive play (greater than about 1/8th inch), as you might want to do from time to time, all you would have to do normally to take care of excessive play would be to jack it up, remove the cap (notice you wouldn't have to remove the wheel) and tighten that nut just a little, one castle in the nut for a cotter pin or one flat of the nut if it uses a retaining tab is usually enough. Under the nut there is the large flat washer (a very few hub setups don't have this large washer but most do) and under it, just as mentioned above, you'll find the outer bearing. When the nut has been removed you can remove the washer and the outer bearing by moving the hub, pulling and shaking it a bit, it will all come apart easily. If its a brake-drum/hub combination you will likely have to adjust the brakes all the way in to be able to remove the hub because it will hang up on the brake shoes. You can adjust the brake in by making the adjustment by prying with a brake adjusting tool or a screwdriver from one of the slots in the back of the backing plate. If you don't know how to do this find someone to show you - basically there is a small knurled wheel in there you have to turn to adjust the brake. As you remove the hub try not to drop the parts in the dirt, particularly if you are planning to reuse the bearings. Put them in a good sized tin-can that's half full of an appropriate cleaning solvent In the past I used to say gasoline but I have, for good reason, been admonished for recommending it as a cleaner. You use whatever seems best to you.
Clean your bearings in the solvent but try not to spin them any more than necessary once the grease has been removed from them. Get all of the old grease out of the bearings if you plan to reuse them (which will be the case most of the time). Inspect the bearings closely for any obvious wear or even discoloration. If there is any question at all about their integrity you should replace them.
Now you have the hub in your very dirty hands. On its rear (the part that was closest to the centerline of your trailer) you will see the seal that is pressed into the hub, and you may have discovered that its been leaking grease out for quite a while. Here's where Microsoft would have put in a link to a parts store that Bill Gates owns along with a smiley face that told you to go buy new seals - seals are dirt cheap (two dollars and change each) so when you go to the parts store to buy them get a couple of extras. Anytime you are repacking your bearings you will have to replace the seals as well. I usually buy them by the dozen!
Behind that seal, moving into the hub from the rear, is the inner bearing. Lets pull all that stuff out of there. You've got to remove the seal from the hub and you are going to destroy it in the process, that's OK. Here's what works for me: I walk up to the front of the trailer and find a place where I can wedge the hub between two frame rails. I jamb it in there and with the grease seal facing me I use a large screwdriver or a long chisel and slip its tip under the lip of the grease seal (through the axle hole) and pry it out of the hub. I use an old cold-cut chisel for this most of the time and just slip it under the lip and give the other end a good bang with a hammer and the seal will usually pop right out. Sometimes they can be a bear to get out but they will come and you don't care one bit if you destroy it because its going to be replaced anyway. Its only made of sheet metal so if worse comes to worse you can actually just rip it apart - I've done it that way, its somewhat satisfying particularly if you've been having a bad week. I've also had some luck using the dog-leg shaped jaw of a pair of channel-locks as a prying device. To do it using the channel-locks I slip the end of the jaw under the edge of the seal and hit the end of the handle with a hammer. Craftsman probably doesn't recommend this use of the tool but I despise Bob Vila (the know-nothing fool just stands around and asks dumb questions while everyone else is working their ass off - particularly Norm, the world's greatest carpenter) so I do it anyway.
Wait A Minute - Is There Something I
should Know Here?
Before we go any farther lets see what the parts of
bearings look like. I'll do this just because it may help understand what I'm
going to be saying later about how to pack them with grease. The bearing has
three major components, an inner collar that actually rides on the axle (but
doesn't necessarily spin on it). Outside from the inner collar there will be
the bearings rollers themselves. These may be balls but more likely they will
be rollers that are some fraction of an inch in diameter (1/4" or less
usually) and about 1/2" long. There will be about a dozen rollers in
there. The rollers will be held in place by an outer cage which is just made of
stamped sheet metal. You will be able to see the outside part of the rollers
where they stick out of the cage. Notice that the shape of the whole bearing
assembly is a straight hole in the center with the outside being cone shaped. Its tapered, that is why they are called "tapered
bearings." There is another part to the bearing that you can't see just
yet, its pressed into the hub, and its called the
bearing race. It has been machined to very tight tolerances and is tapered to
match the cone shape of the bearing that you have in your hand. The race spins
with the hub because its pressed in and acts in effect
as a single piece with the hub and the bearing separates the race/hub
combination from the axle. Because of the press fit the race can not spin
independent of the hub, they are, in effect, one locked piece
Once you get the seal out of the hub you will be able to see the inner bearing. Remove it by simply lifting it out and put it in your can of solvent along with the outer bearing. If you have a 4-wheel trailer its quite likely that the inner bearing will be much larger than the outer bearing. If you happen to have a trailer on which the inner and outer bearing are the same size, as is sometimes the case with 2-wheel trailers, and you are not going to be replacing the bearings but are simply repacking them make sure that you do not mix them up. The reason you shouldn't mix them up is you will need to put the bearing back into the same races they came out of. Think of them as being a matching set because their use causes their wear patterns to become unique. They mate with each other and in this case they mate for life. I'll be assuming that you are replacing everything (which will run you somewhere around $15 a wheel for all new parts from Champion Trailer Parts). Here's a quick plug for Champion (a company with which I have no affiliation) - they have everything you could ever want at extremely good prices and they ship very quickly. They are the best place I know of to get parts unless you have a local shop that can take care of your every need. Now that your bearings have been removed clean out the old grease from inside of that hub. Rags and an appropriate solvent (once again I use gasoline but can't recommend it just because of safety concerns) work just fine for this.
The Bearing Races:
Once you have cleaned out the hub you'll be able to clearly see both the inner and the outer bearing's races. These are the smooth tapered inserts that I mentioned above. There will be one of them in each end of the hub and as you'll recall they are there for the caged roller bearings to ride in. It may not be apparent to you that these are actually separate parts from the hub casting itself and are just pressed into place.
If you aren't replacing the bearings, just repacking them, this is as far as you're going to go with the hub, just inspect the races to make sure that there are absolutely no signs of pitting or corrosion on them. If you see anything that makes their continued use questionable replace the bearing (which will come with a new race). What do I mean by anything? If you see any pitting or corrosion, no matter how small, any scratches, or any discoloration, any dark streaks, I mean just anything that's what I mean. These things are so inexpensive that to take a chance with them is absolute lunacy and I can assure you that once you've had to do this job on the side of the road you'll never take any chance with them again.
Assuming you are replacing everything, bearings and races, and the hub is now clean with no grease in it go wedge down the hub again and get a punch or a drift (or even an old dull cold cut chisel). You're going to remove the old races. Remember - You will not be doing this part if you are not putting new bearing in the hub. You must do this part if you are replacing the bearings.
You absolutely must not use new bearings with the old races. Here's what you do, you can take your drift, or punch, or maybe just a piece of steel pipe or an old chisel that's not particularly sharp and thats small enough in diameter to fit through the hole in the hub and longer than the hub is tall. Moving down through the axle hole you'll find that there is a lip of the race (just a couple of 32nds of an inch wide) protrudes from the inside of the hub. Take your hammer and punch (or whatever tool you are using) and tap on that lip and get the race out of the hub. Hit it in one place then move around the race a bit and hit it again, and move again, and so on. Once it breaks loose it will come out pretty easily but it does take a good solid rap with the hammer to get it moving in the first place. Flip the hub over and repeat the process on the other side and remove the other race. Now clean the hub again. Once its clean take your finger tip and wipe a thin coat of clean grease on the part of the hub that held the race in place and then set the hub aside.
Reassembly!
Now lets put this whole mess back together possibly using new bearings and races, possibly a new axle nut, and certainly a new cotter key (if you had one of those retaining washers rather than a cotter key you may reuse it but you may not reuse the same tab that was bent down previously, just move over to another tab). Of course if your old bearings were in good condition you will not be replacing them but I am writing this as if new bearings are being installed
The first thing you have to do (only if new bearings are being used) is put the new races into the hub. New races are part of new bearing assemblies and are not bought separately. If you are simply repacking existing bearings your old races will still be in the hub.
Take the new race and look to see where its going to go into the hub. The large end of the taper of the race faces to the outside of the hub - this is true on both ends. Think about it for just a second, if you put the race in facing the other way you couldn't get the bearing in. Take just the littlest bit of clean grease on your fingertip and lubricate the seating surface inside the hub where the race is going to go if you didn't do it when you cleaned the hub. Now place the race into the recess with the large end of the tapered part facing out, which is toward you. You can use a soft-metal drift, something like brass (which is best) or place a block of hardwood on top of the race and with your ball peen begin lightly tapping on the edge of the race to begin seating it. Tap LIGHTLY. Tap it into place evenly. Want to know something? I tend to start them by simply taking a ball-peen hammer and lightly (KEY WORD = LIGHTLY) tapping on the upper edge of the race itself. Notice that I'm not recommending that you do it that way, I'm just saying thats what I do. At some point you will not be able to tap it any more with your block and hammer. When that happens break out your drift and lightly tap on the upper edge of the race until it seats into place. Do not tap on the machined tapered part of the race and do not let your drift or punch slip and mar that surface. The race itself must be seated all the way down into its recess. You'll know when its there by the sound and feel if it. All of a sudden instead of going thud it will go ping if that makes any sense to you. Flip the hub over and do the same thing to the other side's race. I'm going to repeat something here - - that race must be seated completely into the hub, no ifs, ands, or buts about it. Now clean the hub again.
Packing Bearings By Hand:
Now you have to pack your bearings. Here's something I should have said earlier but didn't. If you are putting in new bearings or if you are reusing the old ones and have got them good and clean, with all of the old grease out, they are at this moment what is called "dry". By that I mean that they don't have any grease protecting them from corrosion or from scratching. Actually if they are new there will be some sort of packing grease on them from the factory to stop corrosion but that doesn't count. Please don't take that new or clean bearing in your paw and give it a good spin just for the pure hell of it. If you do the result will be microscopic scratches in the rollers because there's no grease there to lubricate them. One of these days those scratches will grow up to be wolfs and they will bite you square on the ass, causing a bearing failure out there on the road somewhere. Now on to bearing packing.
If anyone can describe, in writing, how to pack bearing they certainly deserve the Pulitzer. I'll try to give a good description of it but with little hope of explaining it very well. I'm right handed so I'll assume you're right handed too for my description. If you are left handed do this while standing on your head or something - you know, whatever it takes.
Take a glob of clean grease about the size of a golf ball and plop it into the
palm of your left hand, pull the grease down so the glob tapers as it goes
towards the heel of your palm. Now take the new bearing (or freshly cleaned -
completely cleaned - old bearing if you're just repacking them) and hold it in
your right hand with your first finger through the center hole
to steady it and your thumb on the upper edge to apply downward pressure. You
want the small end pointing up. Remember that the bearing is made up of three
parts; an outer cage, and inner race, and the rollers in-between. There is a
space in-between the inner and outer cages where the rollers are contained. You
are trying to press that Bering into the thin taper of grease in your left palm
such that grease is forced into that little space and completely surround the
rollers. You want to keep pressing, lifting, and moving a bit farther into the
grease in your palm over and over until grease comes out the small space between
the inner and outer cages at the top of the bearing. When it does move the
bearing around a little bit, you know, turn it a bit,
and keep doing it until more grease comes out. Continue with this until you
have had grease come out the space all the way around the bearing. Once you
have done this you will have forced grease to completely fill the voids where
the rollers fit between the inner and outer cages. Its not rocket science
and actually only takes about a minute per bearing once you get the hang of it.
Once you get one done set the bearing aside on a clean surface (a piece of
newspaper is OK) and do it to the other bearing for that hub.
There, you've packed your bearings. Just remember that the goal here is to make sure that you have grease completly coating the insides of that bearing, not simply rubbed around on its outside. If you were to just plaster grease all over the outside of the bearing without forcing it into the void the effect would be a dry bearing under load when you finished the job and first moved the trailer. This would cause extreme heat to be generated because of the initial friction. The heat would melt the grease inside the hub and the void would be filled - so it wouldn't self destruct immediately. But you would have done damage to the bearing before the hot grease got to where it should have been in the first place.
Now with both of your bearings packed you have to install the rear bearing into the hub. Take clean grease and load up the center of the hub with it. Put a good glob of grease all over the inner bearings race (this is the side that will be facing the center of the trailer when its been reinstalled). Take your clean and packed inner bearing and place it into its race. The small end of the taper faces the center of the hub. Now pack grease all over the top of the bearing. Next install the rear seal. Place it over its hole and with your block of wood to protect it tap it into place with your ball peen. Seat the seal flush with the rear of the hub. Don't countersink it into the hub Once the seal is in place, and this is very important, fill the void (a space of about a quarter inch typically) between the bearing and the seal with clean grease. A lot of folks forget to do this, even a lot of shops don't know to do it - but you do. Now set the hub down.
Got A Bad (Grooved) Seal Journal?
Go to the axle and with your solvent soaked rag clean the axle completely. Notice that there is a machined surface at the rear of the axle (closest part of the axle to the centerline of the trailer) where the seal's rubber lip will ride. Make sure that this surface is completely clean. Take emory cloth to it if you have to but get it clean. If you clean the surface with emory cloth clean the axle again by essentially washing it with a solvent - you certainly don't want any abrasive residue from that emory cloth inside of your hub. Next take your finger tip and wipe the slightest amount of grease on this surface, the one where the seal will ride. Here's a hint for you. Sometimes that surface of the axle (called a journal by the way) will be groved just a bit. This is often the case if a seal has failed in the past. You can, if your axles journal is grooved , go back and tap that new seal just a bit farther into the hub than simply flush with the rear of the hub. Doing that causes the seal to ride just a bit farther out on the machined journal of the axle -gives it new metal to seal against so to speak. Once again not necessarly a recommended practice, just something you might want to try if you have to.
Now apply grease all over the axle but not to much up on the threaded part. Get your hub and slide it onto the axle itself. With it on get your already-packed outer bearing and slide it onto the axle and push it all the way on. Notice that the small end of the bearing goes in first so the bearings look like this "><" in the hub with the pointy small ends pointing toward each other and the middle of the hub itself. Put on the flat thrust washer (that has also been cleaned) and then your nut. As you push all this together the hub will straighten up on the axle. Tighten the nut all the way down by hand, just as tight as you can get it by hand.
Clean your hands. Spin the hub by hand - nice, isn't it! There should be no slop in the hub at all, particularly movement in and out from the centerline of the trailer. There's no noise and as they used to say when I was a much younger man, "its slicker 'n a baby's butt." Nice job!
Preloading The Bearings - Getting The Nut Properly Tightened:
Now to finish this up; take an adjustable wrench and tighten the axle nut down quite a bit, not exactly as tight as you could get it by jumping up and down on the wrench but actually quite tight. What you are doing now is sometimes called "preloading the bearings." With the nut over tightened and using whatever you have handy, a long screwdriver put between two of the lugs for the lug nuts is good for this, turn that hub. Turn that hub for about 3-5 revolutions. Continue to apply pressure to the wrench on the axle nut as you do the rotating of the hub. The reason you just did this is that it makes sure that the bearing race is fully and evenly seated. Now go back and loosen the axle nut back up (a couple of turns) but don't turn or pull the hub out off the axle while you're doing it. You have the bearings "pre-loaded" and that's what you want, if you were to move that hub very much it would hurt the effect and you'd have to go back and retighten the nut very tight and do that part over again.
Next retighten the axle nut by hand as tight as you can get it but only as tight as you can get it by hand. Don't use a wrench Does the hole for the cotter key line up with a slot in the nut? Not likely. If not take your adjustable wrench and tighten the nut just enough to get to the next slot and get the cotter key in. Don't make the mistake of thinking that it would be a good idea to turn that nut a bit farther to get it tighter, you know another quarter or eighth of a turn, get that notion out of your head right now. You only want it hand tight and only use a wrench to turn the nut to the very next castle/hole for the cotter key. You do not want this nut to be particularly tight but it must be tight enough that you get no play of the hub on the axle. Once you've done this put your cotter key in and bend one of its legs over the nut and axle and cut the other leg off with side cutters. Fill your grease cap with clean grease and reinstall it by tapping it back in.
Bearing Buddys - Thom Rants For Just A
Few Moments:
If you are using a bearing protector just reinstall it and pump a little grease into it when youre done, but just enough to get the diaphragm of the bearing protector moving out a bit, no more than that. I don't like bearing protectors very much myself. I honestly think those things cause of a lot more bearing failures than they have ever prevented. The reason is simple enough.
Otherwise good and sensible folks use the trailer and then come home, they break out the grease gun and hit it a couple of good whacks with the grease gun. They do this religiously in the name of good maintenances right? Well, that grease has to be going somewhere. Sooner or later enough pumps will have been made that the hub is full, where's the grease go then? If you look at the bearing buddy closely you'll see a little weep hole in its side. The hole's a 64th of an inch in diameter or so. The design has it that when you pump grease in a diaphragm pushes out against an internal spring until the hole is exposed. The spring is supposed to pressurize the grease inside of the hub to a pressure of about a pound and a half per square inch so no water can come back in from behind the seal. The hole lets out any extra grease and relieves excess pressure. That's the plan anyway.
In truth the problem is that the weep hole can't possibly let the excess grease out as fast as even the cheapest and smallest grease gun can put it in. So where does the grease go and how? Well, it goes out and the how is simple enough, it blows out the rear seal, that's how. As bad luck would have it the rear seal is in a place where you won't notice it should the seal fail and in fact if its a brake drum hub you'll effectively destroy a set of brakes before you ever know a seal has failed. Actually bearing buddies are unnecessary anyway but a lot of folks use them, in fact I have used them but you won't catch me pumping grease into them. I just use them as grease caps simply because they are stouter than the stock stamped sheet metal caps and don't bend all up when I pound them into place with a ball-peen (block of wood to protect them? Why?).
Oh, here's why I say they are a joke. The assumption and advertising hype will tell you that your bearings heat up as you drive around, which of course they do to some extent (remember that those hubs should never be a single bit hotter than your tire) but not much. So the marketing hype says that there is great pressure inside of the hub (which isn't true). Then we are told that when the hub is submerged on launching the rapid cooling of the expanded air inside of the hub draws in water, leading to the utter and almost immediate failure of the system. Nonsense. Think about this - if that bearing was heating up in the manner we are told and increasing the hub's internal pressure it would be pushing out grease past the rear seal. But your seals don't leak, do they? So if the pressure doesn't push the grease out, and then the pressure is reversed when the hub cools (according to the hype, but we already know that it wasn't hot to begin with) what on earth makes anyone think that if the seal is good that any water comes in? Utter nonsense. But it does sell a bunch of $10 and $20 bearing buddies of various brands. My point is that if there is not enough positive pressure change as a result of increased heat due to use to cause grease to be forced out of the rear seal then there will not be enough negative pressure change to suck water in on launching. Make sense? Now, having said that I'll again admit that I have used the things but I don't use them to put grease in. I repack my bearing by hand and now days I do it twice a year.
You've done one set now so go clean your hands and drink another beer. Put the wheel back on the trailer and put the lug nuts back on, tighten them down as far as you can with the wheel spinning loosely up there in the air. Do the next wheel then let the thing down off the jack stand, tighten the nuts up, and head for the other side and do it all over again.
There, You're Done - Got Any Questions?
I know that this sounds like a lot of work but it really isn't. Actually it doesn't take any longer to do it than it did to read this, and I can guarantee you it doesn't take as long to remove and repack a set of bearings as it did for me to type this how-to. I don't think I left anything out but I might have and I'm sure someone will step in and let us both know if I did, I hope so anyway. Every time I post it I make a few changes and this time is no exception. Oh, one more thing, I've already said this but its worth repeating - the process described above is really the same if you are just repacking the bearings. The only difference is that you wouldn't remove the old races and install new ones. There's no difference if it is an idler hub, disk brake, or a brake drum hub either. So, got any questions? If you so shoot me an E-Mail at tandjlm@westco.net and I'll do what I can to walk you through the process.
Now A Bit About Bearing Sizes:
Most boat trailer axles are rated for either 2,500 or 3,500 pounds capacity per axle. Most of the smaller axles, which are only found on single axle trailers, will use bearings that are 1 1/16 for their outer diameter. The part number for these bearings is 44649. Most dual axle trailers use bearings that are of different sizes. With the dual axles the inner bearing is 1 3/8 and the outer bearing is 1 1/16 in diameter. The part numbers for these bearings are 68149 and 44649 respectively. This second size is far and away the most common bearing set used in boat trailers. The hubs they mount in are often referred to as either the Small Ford bolt pattern or are called 545 hubs. The 545 designation refers to the fact that they have 5 lugs which are spaced on 4.5 inch centers (from the axle center). These very common 545 hubs use seals that have an O.D. of 2.56 inches and in I.D. of 1.72 inches. A commonly available part number for these seals will be Federal Mogul 473336.
Authors
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Thomas Martin,