Spicer Drive Axles Application Guidelines - Manual (Page 13)

AXAG-0200 June 2009 13
Fire Service
Vocational Description
n Vehicles used to transport people and equipment for the purpose of extinguishing fires or ambulance service
n 90% of operation on prepared road surfaces of concrete, asphalt, gravel, crushed rock, or hard packed dirt and up to 10% of
loaded operation into sandy or muddy areas.
n Mileage is typically under 15,000 miles per year
n Typical vehicle routes are three (3) miles between start and stop
n Vehicle retarders (engine, exhaust, transmission, or electromagnetic) are common
n High engine horsepower and automatic transmissions are typical.
n Loaded 100% of the time.
Typical Vehicle Types
Aerial Ladders Pumpers Tankers Aerial Platforms Ambulances
Vehicle Configuration
4 x 2, 4 x 4, or 6 x 4
Service Definitions
Operation 1
GVW - Straight trucks . Grades up to 20%
General Requirements and Recommendations
•
Additional ratios may be available and would require individual application approval.
•
Maximum allowable torsional driveline acceleration is 300 rad./sec./sec. within the defined operating speed range of the
engine manufacturer. The use of a soft dampened clutch with a manual transmission is recommended.
•
Single vehicle retarders can be approved with all axle models, provided the product selected meets all the application
requirements of the Fire Service vocation.
•
Use of dual retarders (engine, exhaust, transmission, or electromagnetic) is only approved with tandem axle models with
gross axle weight ratings of 46,000 lb or higher and maximum allowable retardation is limited to 100% of max. rated engine
torque.
•
All Electromagnetic retards, such as Telma, require individual application approval by the Dana CVP Application
Engineering Department.
•
This Guideline applies to vehicles operating in the U.S.A. and Canada only. Operation in other countries requires individual
approval by the Dana CVP Application Engineering Department.
•
For optimum axle shaft retention to the hub, .750” dia. studs or .625” dia. studs with tapered dowels are recommended for
single axles with GAWR ratings of 23,000 lbs and above or tandem / tridem axles with GAWR ratings of 44,000 lbs and
above. OEMs are responsible for axle shaft retention on all units not dressed by Dana. See page 80 for illustration.
•
OEM is responsible for isolating vehicle to prevent transmission of gear noise and vibration into passenger cabin of
ambulances.
•
Localized sources of heat, such as engine exhaust, that may cause high axle operating temperatures or reduced seal life are
to be avoided. Maximum intermittent drive axle surface temperature measured at input seal not to exceed 300° F for more
than 30 minutes. Maximum continuous operating temperatures not to exceed 250° F.
•
Dana CVP application approval is required for all vehicles with hybrid power systems.
Housing Structural Ratings
(see table of contents)