Stargazer
Stargazer HalfDork
4/24/09 6:04 p.m.

Anyone use these things on their trailer? I'm not totally familiar with how it works, but it looks like it just packs the housing full of grease, correct me if I am wrong, a wheel bearing shouldn't be packed 100% full of grease. Are they safe to use?

oldopelguy
oldopelguy HalfDork
4/24/09 6:39 p.m.

They are for boat trailers, and yes they do fill the entire housing full of grease and keep it under pressure. Idea is that the positive pressure will keep water out when the trailer is submerged to launch the boat, and for that they seem to work all right. On long trips if the grease heats up they do either allow for a little expansion or if too full force the grease out the inside wheel seal and all over the inside of the rim.

My father used to treat them as a substitute for packing and repacking trailer bearings, which usually left me on the side of the road in -27 degree weather with a ruined trailer. Since none of his trailers are actually boat trailers I went around with a big hammer one day and smashed them all off or to bits and re-packed all the bearings and installed traditional caps. That was the day I finally snapped and cut all his 1 7/8" couplers off too and replaced them all with 2" so I wouldn't have to change balls anymore, and also re-wired them all correctly and to one standard....

Toyman01
Toyman01 Reader
4/24/09 7:29 p.m.
oldopelguy wrote: They are for boat trailers, and yes they do fill the entire housing full of grease and keep it under pressure. Idea is that the positive pressure will keep water out when the trailer is submerged to launch the boat, and for that they seem to work all right. On long trips if the grease heats up they do either allow for a little expansion or if too full force the grease out the inside wheel seal and all over the inside of the rim. My father used to treat them as a substitute for packing and repacking trailer bearings, which usually left me on the side of the road in -27 degree weather with a ruined trailer. Since none of his trailers are actually boat trailers I went around with a big hammer one day and smashed them all off or to bits and re-packed all the bearings and installed traditional caps. That was the day I finally snapped and cut all his 1 7/8" couplers off too and replaced them all with 2" so I wouldn't have to change balls anymore, and also re-wired them all correctly and to one standard....

What he said.

I run them on my boat trailer to keep water out of the bearings. They will blow the inner seals and coat the inside of the rim with grease. On a boat trailer that's not a bad thing. It keeps the salt water from rusting the rims. All my regular trailers get normal dust caps and a repack when needed. A properly packed set of wheel bearings needs little maintenance and no additional grease.

Strizzo
Strizzo Dork
4/24/09 8:33 p.m.

i thought they let the grease heat up and create some pressure so that when they hit the water and get cold real quick they don't suck water that will then trash your next boat trip.

Stargazer
Stargazer HalfDork
4/24/09 11:03 p.m.

Ok, so not a substitute for repacking...kind of what I thought.

Slightly off topic, but what do you do if you're buying a trailer that's sat for a few years, and you need to drag it home 30 miles Just hope the bearings make the 30 mile trip home?

Toyman01
Toyman01 Reader
4/25/09 7:52 a.m.

Drag it home. After 5-10 miles at speed stop and check the temp on the hubs. As long as the dust caps have been on and the bearings were in good shape when parked they should be fine.

44Dwarf
44Dwarf Reader
4/25/09 8:45 a.m.

I'd give each rim a good yang if no slop is felt i'd pop the end cap and squirt some 10/30 on the outer bearing and go! yes the inner bearing will not get lube but at least the outer get help. When home pull clean and repack.

NOTE: Do not use and chlorinated solvents like CRC Brakleen in the red can!! the chlorination will damage the chemical hardening of the bearings surface. USE the green can or plain mineral spirits to clean out the old goo.

foxtrapper
foxtrapper SuperDork
4/25/09 9:23 p.m.
Strizzo wrote: i thought they let the grease heat up and create some pressure so that when they hit the water and get cold real quick they don't suck water that will then trash your next boat trip.

You're close. Has nothing to do with building up pressure from heat, has everything to do with vacuum when suddenly cooled by water immersion. The coil spring holds the slight positive pressure and moves in with the pressure reduction from water immersion, preventing a vacuum and water entrainment.

Stargazer
Stargazer HalfDork
4/26/09 8:00 p.m.
44Dwarf wrote: NOTE: Do not use and chlorinated solvents like CRC Brakleen in the red can!! the chlorination will damage the chemical hardening of the bearings surface. USE the green can or plain mineral spirits to clean out the old goo.

What about PB Blaster? Is that a chlorinated solvent?

44Dwarf
44Dwarf Reader
4/27/09 10:38 a.m.

I don't know read the lable....

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