Keeping Water Out
Your trailer exists so that it can be rolled into the water whenever and wherever you want. So keeping it waterproof allows you to keep doing the boating you love. Here are some tried-and-true techniques and things to consider.
Dust Caps
Dust caps are considered “the basics” of
bearing protection. Look around the boat ramp
and chances are good that half the trailers there
have dust caps instead of a more expensive kind
of bearing protector. But with their simplicity,
dust caps can be high maintenance. These essential
parts of your boat trailer keep dust and dirt
and water from the bearings inside. But if they’re
damaged, and it’s going to happen, every expert
will tell you to toss them and get a new set. Dust
caps work well, but their real benefit is cost,
about $4 – $8 for a pair.
Many BoatUS Trailering readers have written
about dust caps coming off. Sometimes, it’s an
indication of excessive heat caused by bearing or
brake failure.
Caps can come off as a result of damage
when removing to check or service bearings or
when putting them back on. Experts strongly
suggest replacing a bearing cap when bearings
are checked or regreased.
There are instances of a cotter pin on a bearing
not being properly set after changing hubs,
bearings, or grease, and the pin actually touches
the inside of the dust cap, eventually pushing
it off.
If the bearings aren’t adjusted inside the
hub properly, the hub can wobble; this, in turn,
causes the castle nut or cotter pin to loosen.
When removing a dust cap, jack the trailer
tire up so the wheel can spin freely. As the
wheel rotates, tap the dust cap from the top of the wheel so that you’re hitting it in a variety of
places. Many suggest using a flat-edge screwdriver
to do this, which also works (and doesn’t
require the tire to be jacked up). If you choose
this technique, replace the dust cover.
Quick Tip: Add some grease to the inside
of a dust cap. With the dust cap in position over
the hub, place a small 2x4 over it and pound
in place with a hammer. This sets the dust cap
evenly.
Grease-Filled Protectors
Grease is kept around your boat trailer bearings
by a seal on one side of the hub (preferably
a double-lipped seal) and pressure from a rubber
plug or grommet positioned on the outside of
the hub. But there are variations on this technique.
Some modern bearing protectors, such as
Tiedown Engineering’s SuperLube is designed
so that any new grease pumped into a zerk fitting
in the center of the hub will push out and
replace any old grease, which is contained in the
dust cap. During routine maintenance, the rubber
plug is removed and the old grease can be
easily taken out of the dust cap reservoir. When adding new grease, the wheel should
be jacked up so that the tire can spin. New
grease is added until old grease flows out of the
hub near the spindle. This requires looking at
the inner hub while turning the wheel.
It’s important to periodically inspect the
rubber cap or grommet for cracks. If these have
been in place for a while, or the trailer has been
sitting unused for a long period of time, the rubber
parts can dry out
as a result of sun.
Some manufacturers
are using a threaded
reusable dust cap
(Tiedown’s Vortex
Lubrication system
for grease and the
TurboLube system for
oil do this).
Because overdoing
it with grease can
be such a problem, and
can have a bad effect on
bearings while underway,
Kodiak Trailer
offers the Red Eye
Bearing Protector (left),
which is designed to
tell you when grease is, and isn’t, needed. When
a red washer (the eye) is flat against the housing,
grease is added until you can see the “full” mark
when the red washer is extended.
Bearing Buddy
These protectors provide 3 psi pressure of
grease on the bearings inside, making the system
watertight. They can be easily checked by simply
pressing on the “piston” in the center; if it
moves freely, the pressure inside is adequate. If it
doesn’t, grease is applied until the piston comes out 1/8-inch. Many
trailer boaters purchase
a “bra,” a protective
Bearing Buddy dust
cover.
The wood-andhammer
technique
used for dust cap
removal can also be
used for a Bearing
Buddy. There’s no
need to jack the trailer
up either. Just lay the
wood against one side
of the Bearing Buddy
and strike with a hammer.
Then place the
wood on the opposite
side and hit it again. Continue to do this until
you’re able to loosen the Bearing Buddy from
the hub.
Avoid overgreasing (above), which can
destroy the bearings. Too many times a trailer
boat owner will add some grease before every
trip to the boat ramp with the idea that “if a
little grease is good, a lot is better.” So not true.
Continually adding grease adds excessive pressure
to the rear seal of the bearings so that it
blows off. Or, if the rear seal holds, the dust cap
blows off.
Oil Bath Hubs
The semi you see on the highway is probably
running on oil-lubricated hubs. A number
of manufacturers including EZ Loader and
Ranger use oil-bath hubs as standard parts of
their trailers (EZ Loader’s hubs are identified as
“Reliable”; see photo). The upside is this: As
the trailer wheel rotates, oil coats the bearings
through centrifugal force, in many instances as much as four times for every turn of the tire. Best
of all, the oil level can be easily seen by simply
looking at the hub.
Not all trailer manufacturers are onboard the
oil-filled hub wagon, though. Shoreland’r sent
a note to owners two years ago expressing concern
about excessive heat buildup in boat trailers
using oil-filled hubs when dropped in cold
water. The potential exists, says Shoreland’r, of
creating a vacuum inside the hub assembly that
can allow water to enter. That won’t happen with
grease. Another concern is the chance of hitting
a curb with an oil-filled hub, breaking its cover,
and losing the bearing protecting oil right there.
It’s also been argued that oil hubs are a bad
idea if your trailer sits for long periods of time.
The oil will settle, through gravity, against the lower half of the bearings, leaving the upper half
of the assembly prone to contamination. Again,
this won’t happen with grease.
One other note about oil-filled hubs: They’re
not recommended for use with solid rotor disc
brakes because of the heat that is generated. If
you have vented rotors, then all is well.
Both Tiedown Engineering and Kodiak Trailer
make oil hubs. Tiedown offers the TurboLube
system which was a 2001 Marine Aftermarket
Accessories Trade Show Innovation Award winner.
Tiedown recommends changing the oil
every 50,000 miles or two years and to use only
70- to 90-weight oil, avoiding two-cycle. As is
the case with grease, a milky-looking oil indicates
the presence of water.
Kodiak, as a matter of fact, produces a system
(XL Prolube) that can convert hubs from
grease to oil. One component of this system is
the two-part unitized seal that slides onto the
trailer spindle and locks into position while an
outer part spins with the rotating hub, providing
a watertight enclosure for the bearing assembly.
Quick Tip: Use a hand grease gun instead
of an automatic/pneumatic model when refilling
the bearings. Automatic guns operate at too
high a psi and can result on overfilling the hubs
with grease because of the speed and pressures
involved.
