Tiffin Motorhomes 2014 Phaeton, Owner'S Manual

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TIFFIN MOTORHOMES –PHAETON® Chapter 13 ROUTINE MAINTENANCE
An overinflated tire will reduce the tire’s “footprint” (i.e., its actual contact with the road);
thus, reducing the traction, braking capacity, and handling of the motor home. A tire
that is overinflated for the load that it is carrying will also contribute to a harsh ride,
uneven tire wear, and the tire itself will be more susceptible to impact damage.
Maintaining correct tire pressure for each loaded wheel position on the motor home is
critically important and must be a part of regular vehicle maintenance.
Tire Maximum Load Rating
Federal law requires that the maximum load rating be molded into the sidewall of the tire. If one looks at a tire sidewall,
one may see some “typical” information, such as:
Max. Load Single 3640 Lbs at 85 psi cold
Max. Load Dual 3415 Lbs at 85 psi cold
The maximum load allowed for the size tire and load rating and the minimum cold air-inflation pressure needed to carry
that stated maximum load are noted on the tire. Using less air pressure would reduce the load-carrying capacity of the
tire. The amount of air pressure one needs depends on the weight of the fully loaded motor home. Consequently, one
cannot determine the correct air-inflation pressure, unless one knows the actual weights of the motor home.
Weighing the Motor Home
Earlier, in Chapter 1, the procedures for weighing the motor home were
presented (see pp. 1-7 and 1-8). These procedures provided the weighing of an
“unloaded” (i.e., not stocked with the possessions and provisions the user would
normally have onboard for travel) motor home. Obviously, any additional weight
stored onboard (inside and underneath) the motor home will contribute to the
overall weight of the motor home.
If not stored uniformly throughout the motor home, additional weight of the
possessions and provisions of the motor-home user will load each axle and each
tire differently (front-to-rear and side-to-side distribution of that additional
weight). Accordingly, it is necessary to weigh the motor home fully loaded as the user would have it for travel, including
occupants. Moreover, it is necessary to weigh each tire position individually.
Overloading the motor home can produce problems with the tires, wheels, springs, brakes, drive train, and other motor
home assemblies. In addition, an overloaded motor home uses more fuel, is more difficult to handle properly, and can
lead to driver fatigue more quickly. In a worst-case condition, if any component should fail, this could result in loss of
control of the motor home and subsequent damage.
In certain states, the Highway Patrol routinely weighs motor homes to check for overloaded axle weights. Therefore,
there are many good reasons for assuring that the motor home (Figure 13-8) is properly loaded and not overloaded—
this can be accomplished through a proper weighing of the fully loaded motor home.
One can find various places that have certified public scales where one’s motor home can be weighed. For example,
moving and storage company lots, farm suppliers with grain elevators, gravel pits, recycling companies, and large-scale
commercial-truck stops are some of the possible locations for weighing the motor home. One can also check the Yellow
Pages of the telephone book for “scales – public” or “weighers” to determine other locations for weighing
the motor home.
Figure 13-7. Front Tire
13-25
Figure 13-8. Phaeton Motor Home