Ford F series Owner's Manual page 189

Do not exceed the GVWR or the GAWR
specified on the Safety Compliance
Certification Label.
Towing trailers beyond the maximum
recommended gross trailer weight could
result in engine damage, transmission/axle
damage, structural damage, loss of control,
and personal injury.
Use the Safety Compliance Certification Label to
find the axle code number and the engine type
for your vehicle.
Use the appropriate Maximum Gross Combined
Weight Rating (GCWR) chart to find the
Maximum GCWR for your type engine and rear
axle ratio.
Subtract your Loaded Vehicle Weight from the
Maximum GCWR found in the chart. This is the
maximum trailer weight your vehicle can tow
and must fall below the maximum shown under
Trailer Weight on the chart.
RWARNING
RWARNING
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