Specifications
it is strongly recommended that the owner not mix radial and bias tires as it may affect the
trailer/tow vehicle handling and safety. MasterCraft dealers offer replacement tires; if the
owner chooses to go elsewhere, be certain that the replacement tires meet the manufac-
turer’s requirements and integrate with any tires remaining on the trailer.
axles and lubriCation
The trailer is equipped with a Trailer Buddy Axle
utilizing the VAULT bearing protector with specially for-
mulated Hybrid Oil™ lubricant. The VAULT combines the
benefits of oil and grease, lubricating and protecting the
wheel bearings in a sealed pressurized chamber impen-
etrable by outside elements.
The system has a number of unique features not
found on conventional trailer axles. Every possible leak
point on the front and rear of the hub is sealed. The
slight (3-6 psi) pressure within the VAULT system gen-
erated inside the hub chamber will not damage the in-
ner oil seals. The pressure inside the hub is needed
to keep water out of the hub chamber when the hub is
submerged underwater during launch and retrieval.
Inspection or replenishment of the lubricant is not required as part of the routine main-
tenance. At ambient temperatures the oil is thick, with a viscosity approaching grease. As
the bearing temperature rises during towing, the oil thins out, replenishing the bearings with
lubricant and dissipating heat. For optimal performance, only UFP’s Hybrid Oil Lubricant
should be used in this system.
Adding or changing the lubricant in the VAULT system is neither necessary nor
recommended during the first five years of service. After that time, the maintenance
requirements should be undertaken only by an authorized MasterCraft dealer and only
the lubricant specified above should be used.
If the bearings need to be adjusted or replaced, the work should be done only by an
authorized MasterCraft dealer. Failure to contact MasterCraft for pre-approval during
the warranty period will void the warranty.
The wheel bearings have been precisely torque-set at the factory. To assure the
bearings are in good working order, check the bearing adjustment at least once a year by
following this procedure: Jack up one side of the trailer. (Be certain to use jack stands and
check the trailer wheels to keep the trailer from moving during the inspection.) Grip the
edge of the tire and see if it can be rocked or moved. If the outer edge of the tire moves
more than 1/8”, the bearings may need to be readjusted.
A slight amount of oil seepage at the rear seal is normal and necessary to lubricate
the wiper lip of the seal for long life and sealing contaminants out. If excessive leakage is
occurring, however, contact an authorized MasterCraft Dealer for assistance.
braking system
Disc brakes offer several advantages over drum brakes. Disc brakes have improved re-
sistance to fade on downhill grades. They are self-adjusting, so as the pads wear, braking
efficiency is not reduced. This type of brake also recovers quickly after being submerged.
They also require less maintenance, are easier to flush out, and are less susceptible to
water-induced corrosion.
MasterCra Trailer Manual • Page 14