Wheel Bearings

Bear,

I would like to counterpoint this. In our experience most bearing failures we see are shortly after having bearing service. Generally the service is "just because" and not following the guidelines for when to service the bearings found in the owner's manual. Packing the bearings just because it is spring time or because you are taking a long trip we have found to be the main cause for most bearing failures. Improperly tightened in some cases, others (mostly we find) are because too much grease is used. There is a tendency to use what might have been learned from having owned a boat trailer with these bearings and that is not applicable. With a boat trailer you fill the hubs with grease to keep water out, but then again a boat trailer should not go more than 55mph because those are not high speed hubs. If too much grease is in the hubs they run hot at high speeds and cook the grease out. So, when someone says they burned up a set of bearings that generally is the cause.

So no, do not service your bearings once a year whether they need it or not. Follow our guidelines. 1) Every 2000 miles do a end play test by shaking the tire for the proper end play. If the bearings are getting too loose, service the bearings. 2) Tire replacement, service the bearings when tires are due. 3) 50K miles. If you made it that far without doing any bearing service then pack the bearings. The grease is old and should be changed. This number is a tad high based on the light load of the trailer and our experience. The hub manufacturer will actually recommend 25K. So, if you would like to error on the side of caution pack the bearings every 25K if you did not have to for reasons 1 or 2.

Cary

 

Of course though Bear, your three years is more than the average person's three years. You really do have enough miles on to justify bearing maintenance. I suspect the timing of your service is probably exactly when it does need to be done.

Bear brought up a really good point I should talk about. Often times when a shop does bearing service for you they will replace the bearings. This sometimes causes concern for the owner as to why did their bearings need to be replaced. Was there some sort of excessive wear specific to their trailer? Some sort of flaw in the hubs? These questions then get directed our way as to finding out why the shop doing the work did this. The reason is pretty simple. Some shops will automatically just put new bearings in because it is easy to do at that point and very inexpensive. There is no other reason usually. This is normal and not indicative of a issue necessarily.

Cary

 

Yah, just an FYI, I replaced them just cause I thought they "Might?" need it... and shortly thereafter, I had my problem... so lessons learned...

If it ain't broke, don't 'Fix-it;...

Thanks..

 

After reading all this - I picked up a spare set to keep in the TD just in case they ever did go while on the road. Pretty inexpensive insurance.

Bob

 

Great idea. Can you share a link to the bearings you purchased?

 

On page 1 they listed # - I did a search and found them near to my area with very little shipping cost. They weren't stocked locally - I live near a small town.

 

I think that ring is the left over inner race from the previous, destroyed bearing.

 

Old thread but very useful...
I just replaced my bearings and races both sides due to one side being cooked.

I was hearing some squeal at times after a 40 mile drive after a long time in storage, and stopped to check- right side very hot!

I re-read owners manual, and with a couple tips from The Nest and youtube help, was able to DIY.

Dexter has an old video thats helpful


And Cary confirms we dont use a flatwasher between the bearing and castellated nut, and reminds that

The correct technique as in the Dexter video to "tighten then back out the nut" is the key to getting a good fit.

I got bearings at a local RV shop by crossing P/Ns to the numbers in manual and at Dexter. The owner of local RV shop gave me a good tip: to double check fit on inner diameter of the seal matches the spindle axle (it did).

I also got spare bearings and brakes at e-trailer, per Cary's advice, who also confirmed we also dont need the "castellated nut retaining plate" referred to in Dexter video or the " EZ Lube spindle washer"
in the e-trailer kit.
Just the cotter key is enough to hold the castellated nut in place.

https://www.etrailer.com/Trailer-Bearings-Races-Seals-Caps/etrailer/BK1-150.html

Also- Cary strongly reminded in reply to my query: "NEVER use Bearing Buddy" type wheel end caps with grease fittings designed for easy lube on boat trailers.

Those over-fill the hub and they cannot bear the higher heat generated towing at highway speed.

 

BTW, based on grinding noise, at same time as smoked bearing, I'm guessing I apparently picked up a possible pebble in brakes between pad and drum, (or possibly under a magnet?) from gravel roads to and in campground.

Craig suggested backing up slowly and pumping brakes to dislodge and that did the trick!

Once I pulled off the hub I saw the brakes on the hot side were covered in soot from the smoked bearing. So maybe the grinding wasnt a rock but the bearing itself beginning to bind up...

After cleaning the hub with brake cleaner and wire brush, and some spray lube on the springs and adjustment screw, and confirming plenty of pad left, magnets still flat and no major scoring or gouges on drum, I left the old brakes on, just to see if that was separate from bearing fail, ie not a brake problem.

I did get brake spares at e-trailer for next time, just in case.
https://www.etrailer.com/Trailer-Brakes/Dexter/23-47-48.html
Thank you Cary for confirm on the parts at e-trailer.

You can also order hubs at e-trailer if you needed to (like if a rock or metal debris badly gouged or scored the inner hub where brake pads or magnets ride) and I have a spare on order- delivery October 2023!

Cary says these 7" hubs do go out of inventory, and The owner of the local RV shop said they too have had challenges sourcing these smaller Dexter hubs-

apparently not so many Dexter 7" hubs being made in the aftermarket, vs more common 10" size.

So I figure a spare hub makes sense if long use is planned far from easy local sourcing, or finding a shop that can turn and polish a drum surface.

 

That brake assembly work with the "hand brake" option? I need to do bearing maintenance my next weekend home...

 

Sweeney,

The parking brake assembly is a different assembly. This is the one here:
https://www.etrailer.com/Trailer-Brakes/Dexter/K23-103-104-00.html

Cary

 

PS: couple more tips I picked up from watching other youtubes, and a caution by Cary: "be careful when installing new races (what Dexter calls "bearing cups" ) at the same time as new bearings; that you dont scratch the new race by slipppng off the edge onto and scratching the polished surface.

Its pretty easy to tap OUT the old races using a brass drift punch (adding to my tool box...)

But the Dexter video doesnt cover how its much trickier tapping IN the new ones with the drift (or a screwdriver)...without slipping.

Per Cary and my local RV shop owner tip, a much better tool is this:

 

Also, one youtube suggested using emory cloth (I used 320 sandpaper which worked but not as flexible) to polish out any heat discoloration or scored marks from the old bearings on the spindle axle especially on the curved journal surface on inner side.

Emory cloth binds the abrasives to it better. I noticed it was possible for grit from sandpaper to break off, so a good spray-wipe with brake cleaner and dry before grease would avoid sandpaper grit getting in new bearings.

 

And do get yourself a 4" piece of 2x4 to tap in the grease seal evenly...the bearing punch tool works but the wood makes it go in more evenly less likely go deform an edge if you get off centered.

The grease seal double metal lip goes inside, the rubber capped side on outside.

I used this stuff to seal the grease seals edge per Dexter video.

E-trailer has a good video on bearings too:
https://www.etrailer.com/tv-install-trailer-bearings-races-seals-caps.aspx

Again- we DO NOT use "EZ-Lube" end caps, with the grease zirx fitting like in the Dexter video...thats for boat trailers. And you dont use the EZ lube washer that comes in the e-trailer bearing kit referenced above.

 

One more thing...
Cary was curious about the cause of smoked bearing, and in reply to my email with pics said the e-trailer video at bottom of the webpage of the bearing parts kit
https://www.etrailer.com/Trailer-Bearings-Races-Seals-Caps/etrailer/BK1-150.html

Shows "the proper technique" on how much to tighten the outer castellated nut: to hand tighten at end of 12" long wrench (this sets the seal against the curved journal surface of the spindle axle, (and i also used a large channel lock type pliers as in the etrailer video vs the large socket and wrench in the Dexter video.)

But is not so clear in that and other videos "to back out the castellated nut by one flat"
to fix it in place with the cotter pin.

And Cary figures that "too tight" castellated nut adjustment resulting in not enough "end play" is the most common cause of early bearing fails...

And so its that along with over packing the hub with grease (as is normal in boat trailers to keep out water)
is the reason for early bearing fail...

 

My trailer is currently getting the bearings cleaned and repacked as I type this. The shop does a lot of bearings and he mentioned a lot of the things said in this thread.

 

I have no doubt overtightening would be a root cause of failure. It only goes to serve reason that there is such a thing as "too tight" on any surface that moves. I >AM< surprised that "too much grease" is a problem. I know these are light trailers, but I can't see how you'd ever be able to have too much --- lubrication.

Is there a reason for this? If the bearings are bathed you would think they are MORE Protected. Perhaps the grease doesn't liquify properly or can't "move" so contaminates aren't carried away properly?

 

The guy that repacked mine said you have to use the right grease. And even if you use the right grease you have to remove all the old grease. Even a little of the old grease can cause problems if it’s not compatible with the new grease. Either grease is okay but not mixed together.

 

That I know too. I assume brake cleaner and a metric ton of disposable shop towels and at least 3 pair of gloves? Or, just packenough new grease to evacuate the old?

I really dislike working with and around grease...