Drive axle assembly fundamentals Flashcards
what are the four functions of a drive axle assembly
1 - withstand and support the weight of the vehicle and load that has been passed through the suspension 2 - provides the last gear reduction in basic powertrain 3 - must change direction of torque by 90 degrees 4 - must transfer torque between the two wheels wile allowing a difference of speed between the two
the weight rating that refers to how much each axle can carry is called the ?
gross axle weight rating GAWR
the gross combination weight rating refers to the ?
the total combined gross axle weight rating for a vehicle and its trailers
why would a drive axle be added to the rear of a truck rather than a non driving (tag or pusher )
increase traction
the percentage of grade at which a drivetrain system can start a moving vehicle is called
startability
what components are attached to the drive axle housing
suspension - wheels tires and hubs - carrier housing
what is the main function of the carrier housing
hold the internal gear components
is the pinion bearing cage always a removable component of the carrier housing
false it can be a removable piece of the carrier housing or a integral component
how is the over hung pinion different from the straddle mount pinion design
the overhung pinion has a flat surface at the and of the pinion gear and the straddle mount has a short stub shaft that extends past the end of the pinion gear
the input drive pinion is in constant mesh with the
bevel gear
what is the main purpose of the thrust screw
prevents the bevel gear from deflecting away from the input pinion during heavy torque loads
the bevel gear is bolted directly to the
flanged case half
the differential pinions are driven by the
cross shafts
what is the most common differential carrier system used today
single speed reduction
what is the path of power in a single speed single reduction carrier assembly starting with the input shaft yoke and end with the wheel assemblies
input shaft yoke - input drive pinion - bevel gear - differential case - differential cross shaft - differential pinions - axle Side gears - axle shafts - wheel assemblies
what is the components that drives the helical drive gear on a two speed double reduction carrier assembly
shift collar
how is low gear achieved in a planetary differential carrier assembly
when the sun gear is locked to the retainer plate
the torque available to the wheel with good traction in a wheel spin condition is
the same as the spinning wheel
when a vehicle is turning a corner the differential assembly will allow
the outer drive wheel to rotate faster than the inner drive wheel
where is the inter-axle differential physically located
in the front drive axle assembly
what does the input shaft drive with a set of splines
the differential shaft
what are the interaxle differential cross shafts driven by
the input shaft
what two components are locked by the inter-axle differential lockout assembly
the input shaft and helical drive gear
who is a semi floating axle removed
the vehicle weight must be supported and the wheels must be off the ground
what is the input member of the planetary system on a drive axle assembly using a planetary final drive system
the sun gear
what are the two main drive axle lubrication methods
splash lubrication and combination splash / pressure lubrication
how are drive axles filtered
with spin on filters and magnetic plugs and screens
does a differential assembly equipped with a no-spin assembly allow for normal differential action when a vehicle turns a corner ?
yes
when the operator activates the driver controlled differential lock, the operator is mechanically locking what two components together
one axle shaft to the differential case
as the weight of the vehicle increases what will have to bee added to stay within the weight limitations of the road
the number of axles will have to be increased
what do the numbers stamped on the pinion and bevel gear relate to
used to calculate the reduction gear ratio of that particular gear set
what is another name for the drive axle housing
banjo housing
the construction of the axle housing directly relates to the
weight carrying capability of the axle
what is the bowl of a axle housing
the opening with a machined mounting surface in the middle in which the carrier assembly is installed and a flange where the braking components are
what are the two removable caps at the rear of the housing used to secure
the differential case bearings and adjusters
what are the two basic drive pinions used
overhung mount and straddle mount
how is the overhung mount pinion supported
by two tapered roller bearings
what is the purpose of the stub shaft bearing on a straddle mount design
to prevent the pinion gear from deflecting away from the bevel gear during periods of heavy torque loads
how is the straddle mount pinion design supported
with two tapered roller bearings on the long pinion shaft and a single roller or ball bearing on the stub shaft
what type of pinion mount design is more suitable fore heavy torque loads
straddle mount design
how is the thrust screw positioned
exactly opposite the pinion gear
why is the thrust screw positioned exactly opposite the pinion gear
because this is the area where the maximum deflection and thrust loads will occur
what are the two halves of the differential case
flanged and plain
how are the two halves of the differential case connected and supported
bolted together and supported by a tapered roller bearing on either end
what are some of the drive axle carrier assembly configurations
single speed single reduction
single speed double reduction
two speed double reduction
planetary two speed
how is the driver controlled wheel lock operated
air applied and spring released
