bearing grease leaking

[Bob Hammond]

After a 1K miles, the leak has happened again. Apparently the mating surfaces of the cap and hub must not be perfect. i tried to find a new cap but haven't found one so far- the trailer is about 40 years old. The service guy recommended caulking the cap, but I can't see how that will stick with the grease coating the surfaces and/or infiltrating under the caulk.

So I came up with this idea until I can find another cap. it's a seal ring made from a bicycle innertube. I cut a length about four inches long, and stretched it over the cap and hub, and then doubled it over. It was a bit tough but manageable, and it's tight. I'll clean up the wheel and keep an eye on it for the rest of the season.

[featherliteCT1]

Great idea ... I hope it works.

[Squigie]

Good idea.

When I was reading your post, with one eye on the photo, I thought, "Oh, heat-shrink, genius!" But the inner tube is reusable. Even better.


My brother loaned me his "dump" trailer in 2010. Between his house and mine, I lost a grease cap. A phone call indicated that he didn't care what I did to it as a "bandaid", and he didn't want money spent on a permanent repair, as he intended to leave the trailer at the dump the next time he took a load.
So, I cleaned the hub with carb cleaner, cut a Coors can in half, pumped the hub full of grease, and taped the bottom of the can to the hub with Gorilla brand "duct tape". (Super sticktion, extra gooeyness.)

That bandaid lasted for another 6 years. When the next potential owner saw the sun-bleached Coors can as a grease cap, he asked how long it had been on there. My brother told me that, after getting his answer, the guy quipped, "I guess I should pick up a six-pack. It's probably time for replacement."

[bobhenry]

Chucking the cavity FULL of grease is the worst thing you can do. Grease is simply heat released oil. It needs to be able to move, flow and breath a bit. The term used when the cavity is overfilled is churning. As a grease and gear oil formulation tech I attended many training seminars and tech talks. You pack the bearing filling all the areas between the cage and the roller bearings, leave a thin spread over the bearing and add a small ping pong ball sized wad as reserve. If you PACK the cavity it will expand when heated and leak out the cap!

[Squigie]

The concept is valid. But a hub packed full of grease is more likely to push the grease past the lip seal behind the inner bearing, than around the cap.

If you have grease coming out around the cap, one or both of the mating surfaces are damaged and not sealing.
If you have a hub literally packed full of grease, the mess will be present on the back of the hub / inside of the tire and wheel, and in/around the fender and underside of the frame. It usually ruins the seal, too, by pushing the lip out over dirt and rust on the spindle.

[bobhenry]

Look real close at the picture posted. If you peer thru the rim cut outs you will see grease on the outer rim face on the inside of the rim as well as the outside so you are right it is being jettisoned out the seal as well as the cap.

[Bob Hammond]

Look real close at the picture posted. If you peer thru the rim cut outs you will see grease on the outer rim face on the inside of the rim as well as the outside so you are right it is being jettisoned out the seal as well as the cap.

That's not so. i looked carefully at the inside of the rims and seals. They're tight and dry. The issue is the imperfect mating of the cap and hub.