The Great Australian Furphy – Bearing Protectors
Tired of Throwing Money away on Boat Trailer Bearings?
Boat Trailer bearings have been a problem for a long time and continue to be a problem for many boat owners.
Worn bearings and even worn stub axles are a result of water ingress into the hub.
Water entry into hubs is generally through the back seal and is a common boaties problem. I need a better marine seal, yes that is a FURPHY. Marine seals are useless.
Current Australian and US marketing says use Bearing Protectors and then pressurize your hub to 3psi. You will not get water ingress because the tension in the bearing protector spring will counteract the contraction in the cavity due to cold water immersion. That is also a FURPHY.
Pressurizing bearing protectors at 3psi in a cold hub only results in that pressure being released on the highway when the hub is hot. As the hub gets hot, air expands………remember that spring was under full tension at 3psi when cold? Now the expanded grease isn’t going back inside the bearing protector or bearing buddy because the bearing buddy is already loaded and under full tension.
Since there is nowhere for the grease to escape except through the back seal, WALLA grease over the inside of our trailer hub.
In fact, as the hub grease gets hot and fluid, the grease in the bearing protector is starting to escape in to the bearing cavity and then out through the back seal?
There is a lot of talk from experts about putting good quality bearings into your boat trailer, and THAT IS the remedy for failed bearings. Another FURPHY.
True, bad bearing fail but it is generally not the root cause of a boaties bearing problems.
Bearing failure due to WATER INGRESS is the root cause of a boaties bearing problem and it’s now a thing of the PAST for most boat owners.
Australian company Couple-mate has found the science to the BEARING FAILURE SOLUTION
Couple-mate discovered that putting a hot trailer hub in to cold water causes the air inside the hub to contract. This contraction causes water to be sucked in through the back seal. Simple as that.
After years of testing, it has been found that water generally enters the hub through the marine seal and more precisely water enters around the outside of the marine seal. (given there is no wear on the bearing journal)
Couple-mate inserted a rubber diaphragm on the outside of the dust cap (or rubber grommet). The rubber grommet is pushed out as Air Expands and then is sucked into the bearing cavity when contraction occurs.
It is the rubber grommet that expands and contracts due to dramatic changes in air temperature.
Boaties still check their wheels and apply regular maintenance but they are not buying bearings.
Bearing failure is being minimized in the Australian market for boaties using Couple-mate Premium Dust Covers.
Grommet dust covers are standard equipment on American trailers, especially boat trailers.
Couplemate have produced a set of dies to suit Australian hubs and produced a stainless Grommet dust cover.
Using the grease nipple on bearing protectors to insert fresh new grease on top of OLD DIRTY grease is NOT recommended as this will accelerate bearing wear.