be on the side opposite the fuel dispensing equipment. For dual fuel servicing vehicles, the
outlet, may be on either side. All portions of the exhaust system which project to the rear of the
cab shall be fully shielded from fuel sources. The shield(s) shall direct fluids spilled from the
tank, leaking from the tank, spraying from any leaking seals, or from any other source, away
from the exhaust system. Shields shall be separated from the exhaust system component to be
shielded by at least 0.50 inches for the top half of the component and shall extend vertically
down from the horizontal center of the component to at least the bottom of the component. The
shielding shall not interfere with the servicing of the pump line strainer or any other component
under the tank body requiring periodic servicing. A spark arrester conforming to SAE J350 shall
be furnished except on turbocharged engines. The spark arrester shall have an 80 percent
efficiency rating when rated in accordance with SAE J350.
18.104.22.168 Exhaust gases in cab. The exhaust system shall be installed in a manner that will
insure that the concentration of oxides of nitrogen (NOx) shall not exceed 5 parts per million
(ppm), the concentration of carbon monoxide (CO) shall not exceed 50 ppm and the
concentration of sulfur dioxide (SO2) shall not exceed 5 ppm in the driver's compartment after
eight hours of operation with all windows and doors closed, with cab air intakes open, with and
without all cab heaters operating, and with the chassis engine operating in accordance
3.4.5 Transmission. Unless otherwise specified (see 22.214.171.124), a manually shifted
transmission shall be provided. The input torque capacity of the transmission shall be at least
equal to the maximum torque delivered by the engine. The vehicle shall be provided with not
less than the number of forward speeds specified in table VII. When more than five forward
speeds are required, a multispeed transmission or an auxiliary transmission shall be provided.
Gear ratios in the transmission and axle shall be matched to provide a progressive shifting
pattern throughout the complete range, and shall provide the vehicle performance required in
3.3.1 through 126.96.36.199. The transmission shall provide for maximum ease of shifting in all speeds.
SAE J704 power takeoff opening(s) shall be provided.
TABLE VII. Vehicle number of forward speeds.
Number of forward speeds