Am I the only one who has this problem?

I keep getting trailers that leak grease at the metal seam between the cap and the hub. This particular one was fine until I pulled it off to service the bearings. Then 100 miles into the trip I see grease all over the outside of the wheel.

now, granted, this cap is original from 2009. But there was no signs that it would leak before heading out. The other side did the exact same thing on the way home from a trip several years ago.

I ask because this isn’t a one-off problem.

my car trailer is leaking now and it was fine until until now. Our scout trailer is leaking now exactly the same. It was fine all last year, and now on the first trip out this year it is leaking grease.

am I doing something wrong? Two of the trailers started leaking without me touching them.

adding insult to injury, TSC charges $30 for these stupid caps when you can get a pair online for about $12

 

I've seen them sort of show oil moisture like your pic sort of shows but have not seen grease actually coming out.

 

Same here, the seam gets wet looking but none of mine have slung out any grease.

 

I usually replace them when I have the drums off for full bearing service. They are currently $16 for a set of four on Amazon, including new rubber plugs for those EZ-lube hubs. That's if you have the 2-7/16" size. Because the grease is coming out at a specific spot, I think they were nicked or kinked when you last knocked them out.

 

Could be too much grease in them as well.

 

I would normally agree, but those caps have rubber plugs and the centers are very flexible. When the grease heats up those plugs pooch out from the pressure.

 

I’ve gotten them too full before and had them blow grease out the back. They aren’t over full. They are full, but not over full. I’ve developed a method that works for me to make sure they are full but leave plenty of room for expansion. I can post a picture of the inside of the cap tomorrow. There is some grease on the inside of the cap, but it’s about a 1/8” thick ring of grease that got spun off the front bearing. Nothing excessive.

a new cap solved the leak, but now I got bigger problems. I got to my destination in Theodore Rosevelt National Park and noticed the camper had an odd bounce at low speed. Stopped at the campground and spun the wheels. Somehow on the trip from the black hills to North Dakota today I managed to ruin both tires on the camper. Both of them are twisted and bulged. Fine when I left, ruined along the way. Got the spare on but I’m still short one to get us home.

ordered two to pickup in rapid city on Friday, but gotta find at least one here to get us back to the hills.

camping is fun…

 

There might be too much grease in there.

Bearing Buddy Bras should catch the excess that comes out. Might want to pull them and empty them from time to time until they stop collecting more.

 

Perhaps a silly question and not trying to be insulting...just trying to help... but what grade grease did you use? I use NLGI Grade 2 in wheel bearings. I've used Grade 1 (thinner than Grade 2) in odd applications like older steering gear boxes.

Probably a bad fluke with the tires or maybe you hit some freaky weird road bump.

 

Yeah, camping can be a lot of “fun” at times, been there, done that. Found all 4 toyhauler tires had thrown off large chunks of tread after the first towing day of a 3 week trip, besides the tire replacement the vibrations from the torn up tires broke the refrigerator coil, so that had to be replaced too. And the vibrations also caused some 110V wiring to shake apart and ground out burning up about 18” of Romex. Almost too much fun for the first day of a trip!
What brand tires are they? How old are they?

 

No purpose for grease in the cap. If you grease the spindles with an EX lube style spindle you turn the wheel while you grease and then clean out the grease before you put the rubber center back in. That grease in the cap isn't lubing anything and if it got hot enough to flow the bearings are probably on fire.

 

this round was mystic jt6 high temp. It is a NLGI grade 2 lithium complex grease.

last round was Valvoline Crimson high tack NLGI 2. Also a lithium complex grease.

 

tires are carslile raidal trail HD in a load range E. Installed in early 2021, date code in late 2020. They have about 6,000 or 7,000 miles on them.

I hit some wicked bridge ends that made me cringe a few times. I think that’s what killed them. Just a guess though.

I’ve got my spare mounted on one side and I found a local store that has a china bomb to buy that will get me back to Rapid City where there are two brand new Carlisle tires waiting for me.

 

the caps went on dry and clean. I used the ez lube nipple to flush them and I wipe off all the excess grease in front of the outer bearing before installing the cap.

the grease will always flow, that is what it is supposed to do. There is a very thin layer that was expelled from the outer bearing while it was in use. My bearings never get hot. Every time I’ve checked them they are always the exact temperature of the tires and rims. I used to check them with an IR, but I don’t anymore. They just never get hot.

 

Yes, the grease leak appearing in one specific spot of cap gap cannot be ignored, @meborder .

There could be a granule of a tiny rock fragment or other debris that adhered to the film of grease that was wiped out of the hub opening before the cap was installed.

The dirt or debris could have been on the rag or paper towel used to wipe out the excess grease.

When installing the bearing caps, I use a hollow cylindrical tool that pushes directly on the sealing lip flange itself, and only on that circumferential flange lip... without any pressure applied to the outward facing top rim of the cap.

I've seen cap installation tools that I coveted, but did not know the source of, so I made an cap installation tool myself out of a 2" EMT coupler, made of die-cast aluminum (or pot metal).

New bearing caps are not made like they used to be. I have 3 trailers, all of which are more than a quarter of a century old, all of which have EZ-Lube hubs, and all of which have bearing caps made of thick metal, by Dexter, when they were manufacturing such parts in the USA. Any new bearing cap made today is imported, and is about half as thick.

I bought some new caps thinking that it would save me time from cleaning up the old caps, and when I compared them side by side, I put the new caps back in the bag they came in, and put the old caps back on my trailer. There was that much of a difference. And I did NOT order the new caps off of Amazon... I bought them from a bricks and mortar local and officially authorized Dexter distributor. Still crap by comparison to the original caps. I did use the new rubber plugs however. Those were thinner than the originals too, but unlike galvanized metal, rubber, no matter how thick, eventually disintegrates.

Consider carefully whether or not there is any benefit to packing the entire hub cavity between inner and outer wheel bearings with grease via the EZ-Lube zerk.

I pull the hub drum assembly and hand pack the bearing cones individually... using one of those Lisle wheel bearing packing tools. This avoids the EZ-Lube risk of pushing grease past the inner seal into the brake and magnet area.

I've seen SpewTube videos demonstrating how EZ-Lube is "supposed" to be done, and the demonstrator pushes an entire tube of grease... into each individual wheel, using 4 to 6 tubes of grease just to lube the wheel bearings of a tandem axle trailer, and an entire roll of paper towels to collect all of the "old" grease pushed through the hub and bearings in the process.

I'm not signing up for that type of waste of time, pumping energy, and materials. Since pulling the hubs and drums, inspecting the brake and magnet area, including lining thickness and any binding in mechanical operation, while lubing backing plate wear points, is a recommended maintenance routine for safety anyway... then might as well hand pack the bearings while in there, and not bother with that full tube of grease per hub push it all through madness.

Perhaps there is still an excess amount of grease in your hub cavities, which when heated from running down the road, expands, and also becomes runny, with the oil content separating from the thickener, and escaping through any imperfection of your bearing cap gap.

If you are confident that this grease is not also escaping into your brake area through the inboard seal, then perhaps the only downside to your status quo is dirty wheels.

This too, can be mitigated, with hub caps, which cover the cap to hub seam, and thus might, in theory at least, capture any rooster tailing of separated oil leaking out of a less than optimal cap to hub interface. Another benefit to hub caps is keeping the sun off of the rubber plug.