Wheel Bearings

Replacing the bearings is a bit more involved than squeezing grease into the bearings. The process includes removal of the hub, the same process you would use if you hand pack the bearings. This is the time when you should also service the brakes since you will have them entirely exposed when you do this service. Have lots of paper towels, brake cleaner and rubber gloves handy for this job. To replace the bearings you will need to start by removing the wheel. Do one side at a time. Be sure that you have properly supported the trailer/axle before you start. Once the wheel is removed you will next remove your wheel hub. To do this you will need to back off the brakes to makes sure they will allow the hub to slide off. Remove the grease cap. Then remove the cotter pin locking the castellated nut. Removing the pin will allow you to thread the nut off. Once the nut is removed you can pull the hub loose. Clean the spindle and look for wear or any damage. Take the removed hub and remove the seals. With the seals out of the way, the bearings can be removed. With bearings out of the way the inner races can be carefully drifted loose. There are specific tools for this purpose but most folks do this job with a hammer and brass drift. Carefully clean the inside hub and look for wear or damage. Assuming that all is well, start to replace the bearings by carefully tapping the new inner races in place. They must completely seat. Once these are in place you may install the thoroughly packed bearings. After the bearings are installed the seals are replaced. Be generous with grease and be meticulously clean. With the seals installed you are ready to put the hub back on the spindle. Again, grease everything as you go taking care to avoid getting grease on the inside braking surface of the hub or the brakes. With the hub in place you will slip the D washer onto the spindle followed by the castellated nut. Tighten and turn, tighten and turn until the hub begins to stick. Back the nut off enough to install the cotter pin and Bobs your uncle. Bang the grease cap back on and finish up by adjusting your brakes. 

Keep track of what kind of grease you use when you do this. Use same brand/blend whenever you service the hubs.

tabiphile said:

Replacing the bearings is a bit more involved than squeezing grease into the bearings. The process includes removal of the hub, the same process you would use if you hand pack the bearings. This is the time when you should also service the brakes since you will have them entirely exposed when you do this service. Have lots of paper towels, brake cleaner and rubber gloves handy for this job. To replace the bearings you will need to start by removing the wheel. Do one side at a time. Be sure that you have properly supported the trailer/axle before you start. Once the wheel is removed you will next remove your wheel hub. To do this you will need to back off the brakes to makes sure they will allow the hub to slide off. Remove the grease cap. Then remove the cotter pin locking the castellated nut. Removing the pin will allow you to thread the nut off. Once the nut is removed you can pull the hub loose. Clean the spindle and look for wear or any damage. Take the removed hub and remove the seals. With the seals out of the way, the bearings can be removed. With bearings out of the way the inner races can be carefully drifted loose. There are specific tools for this purpose but most folks do this job with a hammer and brass drift. Carefully clean the inside hub and look for wear or damage. Assuming that all is well, start to replace the bearings by carefully tapping the new inner races in place. They must completely seat. Once these are in place you may install the thoroughly packed bearings. After the bearings are installed the seals are replaced. Be generous with grease and be meticulously clean. With the seals installed you are ready to put the hub back on the spindle. Again, grease everything as you go taking care to avoid getting grease on the inside braking surface of the hub or the brakes. With the hub in place you will slip the D washer onto the spindle followed by the castellated nut. Tighten and turn, tighten and turn until the hub begins to stick. Back the nut off enough to install the cotter pin and Bobs your uncle. Bang the grease cap back on and finish up by adjusting your brakes. 

Keep track of what kind of grease you use when you do this. Use same brand/blend whenever you service the hubs.

Are you replacing the inner races just to be on the safe side?  I've never replaced them unless the bearing had gone bad and scarred them.  Maybe I was doing bearing replacements wrong.  Also couldn't you just repack the bearings if after they were cleaned out of all the old grease, they still spun smooth and didn't show any signs of damage?

@N7SHG_Ham has it right...if you are replacing one do both. The parts cost is minimal and the relative effort is also. 
If the bearings are running smoothly, if the grease looks good, if there are no signs of failure, sure, clean and repack. But don't try to make a bearing last forever. They will fail. If you have never seen a wheel drop off an axle just wait...it's ugly. The Dexter EZ lube can give a false sense of security. At some point a proper hubs off service should be done along with a proper inspection of the hubs, bearings, races, spindles etc. Brakes should be done at the same time.
One thing that was neglected previously is that you should always use a torque wrench on the wheel lugs when you replace them. Guessing tightness is a gift that some mechanics possess. The rest of us should measure it.

The Dexter service manual is the authority, inspection of entire axle end 12k/12mo, no shortcuts for pumping grease in as an alternate service and no exception for low miles, the 12mo seems to come every year whether you have towed or not.

https://www.dexteraxle.com/resources/manuals

@qhumberd...welcome to the forum. Congratulations on the new rig! 
There are a few ways you can play this. Are you a risk taker? If yes, pump some grease into the Alemite fittings and haul it home. Stop a few times and check the hubs and wheels to see if they are heating up. A hot bearing will announce it's presence (usually) before it fails. When you get home, take your T@B to a local trailer service shop and have them do a complete service on it. 

Or...if you don't know for certain if the bearings were properly greased before those 3,700 miles and you want to play it safe, take it to a trailer or RV service center and get it taken care of before you go. Better safe than sorry. Still stop every now and then to check to see if things are getting hot. That's a good habit to get into when you tow.

One way or the other the service should be done....
Most auto shops don't like to deal with trailers. The mechanics are capable and qualified but it's not a job that's normally in their wheelhouse.

NuCamp recommends bearing maintenance annually or every 12,000 miles - whichever comes first.  The confusion is the ability to use the zerk fitting to add lube.  I know members quote Dexter as requiring a full repack annually, but what is the purpose of the easy lube system?  For low annual mileage use, can you get away with every other year repack alternated with use of the zerk and careful monitoring?

I only started using a trailer in late 2017. Before that the only time I thought about wheel bearings was when, as a kid in the early 70s I messed around with old VWs. I owned three of them and they took up too much of my time. Does anyone know why our T@B trailers don't have sealed bearings? Is it possible to convert to sealed bearings without replacing the whole axle?

@GrandmasKid, I always take my T@B to a utility trailer business once a year or 12,000 miles (last year it was serviced twice) for them to service the bearings. It is so much easier for me. I hate getting greasy and this solution works well for me. He also checks and adjusts my brakes at the same time. Around $100 is a price I’m very willing to pay. 

tabiphile said:

GrandmasKid said:

Does anyone know why our T@B trailers don't have sealed bearings? Is it possible to convert to sealed bearings without replacing the whole axle?

Sealed bearings are not well suited for TT apps. TT's (unlike wheel bearings on a front wheel drive car as an example) do not have CV joints to help manage the loading stress. Loading stress? Think about low pressure in a tire and the swaying while towing. Cost is also a consideration. Wheel bearings are generally very cheaply made poor tolerance assemblies, a reason why the TT industry demands that they are serviced so often. Sealed bearings are not adjustable. You get what you get...the typical roller bearings used in TT's are adjusted by you when you install them...that's the turn the wheel back and forth thing you are doing while you tighten the nut. There have been sealed bearing used in the TT industry, and many of them have failed. 
Can you install sealed bearings without an axle change? No. The sealed bearing axle is part of the tolerance stack that makes them work. The axle needs to be designed to accept the sealed bearing.

Sealed bearings are not a panacea...anyone who has owned an all wheel drive performance vehicle has experience the whoop whoop whoop of a failing wheel bearing and the horrifying price tag that comes from replacing them....60 to 100,000 miles is about when they make their presence known. always just out of warranty.

Tapered bearings also have a much higher load bearing surface relative to their size, hence larger capacity. Autos use sealed ball bearings because of their lower friction coefficient. They are okay, but for self servicing and longevity, nothing yet beats a tapered bearing.
WilliamA

N7SHG_Ham said:

It is more than the grease as to why an annual or 12k interval for an actual pull about and look see. Seals, brakes and so on can be inspected, the brakes adjusted and the bearing pre load adjusted.

IMO, careful and regular hub assembly maintenance as recommend by Dexter will go a long ways toward not leaving you with a mechanical failure beside the road. That and tire maintenance are the two most important pieces to safe towing, everything else is pretty much cosmetic.

Don't skip on the important stuff.

Wholeheartedly agree! Take care if yoyr bearings and thry will take care of you!