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Calculating Tow Capacity:
Several variables must be reviewed and
calculated to properly determine towing
capacity. Limiting factors include GCWR
(Gross Combination Weight Rating), GAWR
(Gross Axle Weight Rating), hitch receiver
weight rating and the weight rating of each
piece of towing equipment. One or some of
these variables will limit tow capacity.
Example:
The tow vehicle has a GCWR
of 35,000 lbs. The tow vehicle in a fully
loaded, ready for travel condition, weighs
29,500 lbs. The hitch receiver is rated at
700 lbs. tongue, 7000 lbs. tow. The load
being towed weighs 4,200 lbs. with a
tongue weight of 400 lbs. However, the
hitch ball is rated at 3,500 lbs. In this
case tow capacity is limited to 3,500 lbs.
due to the rating of the hitch ball, even
though the rest of the towing equipment,
hitch receiver and vehicle GCWR are
within specifications.
It is possible to be within the GCWR but
exceed the GAWR. When tongue weight is
applied, mechanical advantage increases with
distance (lever) from the hitch ball to the drive
axle. The drive axle now becomes a pivot point
(fulcrum).
As tongue weight increases (effort), weight
on the drive axle also increases (fulcrum)
while weight on the front axle decreases (load)
as weight is displaced from the front axle.
It may be necessary to weigh both the tow
vehicle and towed load as an assembly to
ensure the GAWR has not been exceeded.
It is also possible to be within the rating of
the hitch receiver and yet exceed the GCWR.
Due to changes in weight, the motorhome
must be weighed in a loaded, ready for travel
condition that includes passengers, cargo and
liquids. Subtract the weight of the motorhome
in a loaded, ready to travel condition from the
GCWR to determine tow capacity. Whether
towing a vehicle or trailer, the load being
towed must be weighed to ensure the towed
weight, when added to the tow vehicle, will
not exceed the GCWR and the weight ratings
of each tow system component are equal to or
greater than the load being towed.
WARNING
The motorhome and towed load must
be weighed after they are loaded for
travel to determine if actual weights
are within towing specification. Each
component of the towing system must
be rated equal to or greater than the
load being towed. Do not exceed the
Gross Combination Weight Rating.
Taillight Configuration:
Taillights come in a 2-wire or 3-wire
configuration. A 2-wire configuration has all
red lens. A 3-wire configuration usually has
red and amber lens. Amber is used for turn
signals only and red for taillight and brake
light. These systems are electrically different.
Whenever hooking a 2-wire system to a 3-wire
system, or vice versa, a converter box must
be installed for correct taillight function. A
taillight converter is available from auto and
RV supply stores.
DO NOT
attempt to wire
a tow plug connector if unfamiliar with these
systems. A trained technician will install the
proper converter so the taillights and turn
signals work correctly on the motorhome and
towed vehicle or trailer when the tow plug
connection is made.
090512
Ball Mount
Weight Rating
Hitch Ball
Weight Rating
090512b
090512F
GAWR Tow Weight
Tongue
Weight
Summary of Contents for 2011 Aluma Lite
Page 10: ...Notes...
Page 42: ...40 Dr ivi ng s afet y 2 Weight Record Sheet...
Page 48: ...46 Dr ivi ng s afet y 2...
Page 72: ...70 e x t e r i o r I n t e r i o r C a r e 3...
Page 140: ...138 w a t e r s y s t e m s 6 Water System Diagram Typical 040487q...
Page 152: ...150 P r o p a n e s y s t e m s 7 Notes...
Page 180: ...178 E l e c t r ic a l s y s t e m s C h a s s i s 9...
Page 185: ...183 C h a s s i s I N f o r m a t i o n 1 0 Weight Record Sheet...