Great Dane 42101401 - Manual (Page 21)

19
TIRE LOADS
Great Dane Trailers, as required by the safety
regulations of the National Highway Traffic Safety
Administration has assigned a Gross Axle Weight
Rating (GAWR) for each axle on the undercarriage.
(See example certification plate below.)
The GAWR and tire information shown on the vehicle
certification plate was applicable at the time the trailer
was manufactured. If the tires or other components of
the running gear have been changed or altered since
the trailer was manufactured, the GAWR may have
changed. This should be checked with Great Dane
Trailers Customer Service Department.
AXLE ALIGNMENT
Improper axle alignment with the trailer frame will
cause excessive tire wear and trailer “dogtracking”.
In extreme cases, depending on trailer length, the
outer tire of the curbside wheels may have little or no
contact with the road, causing the entire wheel load to
be carried by the inner tire. Also, trailers that “dogtrack”
will not have identical right and left turning characteris-
tics, which complicates driving in areas with narrow
streets and sharp turns. Even though Great Dane
aligns every trailer’s axles prior to delivery, we still
recommend that axle alignment be checked and
corrected if needed on initial in-service and again
every 20,000 miles.
When aligning axles, suspension should be in a natu-
ral, relaxed state, free of any “binds” before taking
measurements. To achieve this relaxed condition,
make sure the vehicle is unloaded. Then roll it back
and forth on a level floor. Avoid brake application
including parking brakes. Vehicle must be level from
side to side as well as from front to rear.
To inspect the axle alignment, measure the distance
from the kingpin to the trailer axle on each side (and
from axle to axle for tandem-axles) as specified below.
But first fabricate a rigid S-hook that can be hooked
over the kingpin and attach a steel tape to it.
SINGLE-AXLE PROCEDURE
1. Remove any parts of the undercarriage that will
interfere with the tape when it is stretched between
the kingpin and the ends of the axle – or avoid
removing the parts by using a Sweeny pogo stick or
equivalent device. Remove outer wheel if disc type,
or tire and rim assembly if steel spoked, or entire
assembly – depending on the wheel equipment on
the trailer.
2. Level trailer to its normal road condition.
3. With the S-hook and steel tape, measure the
distance from the kingpin to the center of the end
of the axle on each side (measurements A and B on
the single-axle illustration). These measurements
must be within 1/8" of each other.
TANDEM-AXLES PROCEDURE
1. With the tandem axles in their natural working
position, roll the trailer back and forth over a level
surface a few times to permit the connecting linkage
to position itself properly and center front and rear
wheel track.
2. Remove any parts of the undercarriage that will
interfere with the tape when it is stretched between
the kingpin and the ends of the front axle – or avoid
removing the parts by using a Sweeny pogo stick or
equivalent device. Remove outer wheel of this axle if
disc type, or tire and rim assembly if steel spoked, or
entire assembly – depending on the wheel equip-
ment on the trailer.
3. Level trailer to its normal road condition.
4. With the S-hook and steel tape, measure the dis-
tance from the kingpin to the center of the end of
the front axle on each side (measurements A and B
of the tandem-axles illustration).
These measurements must be
within 1/8" of each other.