Spicer Drive Axles Application Guidelines - Manual (Page 41)

AXAG-0200 June 2009 41
Rescue
Vocational Description
n Specialized all wheel drive vehicles designed for rapid acceleration to airport crash sites
n Operation on road surfaces made of concrete, asphalt, maintained gravel, crushed rock, hard packed dirt, or other similar
surfaces for 90% of the total miles and sandy or muddy crash sites for the remaining 10%
n Extremely low mileage operation
n High horsepower engines and automatic transmissions are typical
n Vehicle retarders are common (engine, exhaust, transmission, electro-magnetic)
Typical Vehicle Types
Airport Rescue Fire (ARF) Crash Fire Rescue (CFR)
Rapid Intervention Vehicle (RIV) Emergency Service
Vehicle Configuration
4 x 4 or 6 x 6 specialized straight trucks
Service Definitions
Operation 1
100% loaded full time. Grades of 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 Rescue vocation.
•
Use of dual retarders (engine, exhaust, transmission, or electromagnetic) is approved with all tandem axles with maximum
allowable retardation 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.
•
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)