Driveline fundamentals and service Flashcards
what is a drive train
the entire arrangement of various major components and connecting drivelines
what is the basic function of a driveline
to transmit power from the drive unit to the driven unit
when are single drivelines used
if the operating distance between a drive and driven unit is within allowable limits
what determines the limit of the driveline length
shaft torque loads - shaft speeds and diameter of the tube
when are multiple drivelines used
when using a tandem rear axle
what is a midship bearing
a support bearing for a long driveline used to carry the weight of the first shaft and secure its position in relation to the second shaft
driveline construction is usually made up of several different components that must be
welded together and balanced
what might be the cause of a slightly bent or twisted driveline tube
vibration
what is the purpose of U-joints
they allow the transmission of power from one major component to another
what should be remembered when installing the u-joints
the grease fitting is installed so it wont interfere with other components and is easily able to be greased
what is a trunnion
a highly polished bearing surface at the end of each universal joint cross arm
what is in each bearing cap that fits over the trunnion
needle bearings
when installed in the yoke the universal joint bearing cap and trunnion bearing cap allows for
a certain amount of pivoting action to occur
yokes are
the devices used to make connections to universal joints
what type of yoke would allow the shaft assembly to change in length
slip yoke or (sleeve )
what will regular lubrication help provide on a slip yoke
control load stress on the splines and enables the splines to smoothly slide together during operation
what is another name for a mid-ship bearing
a steady bearing
the center support bearing is
a sealed bearing and cannot be lubricated
why should you never wash an old center support bearing with solvents
because this would remove the grease from the bearing making it unserviceable
what is one way to protect an old center support bearing
packing water resistant grease around the outside of the bearing on both sides
what is the maximum working angle difference allowable on a parallel drive shaft design
1 degree
what is a broken back driveline
when the major components are to close for a parallel design . so the center line of the drive input and output intersect when extended toward each other over the middle of the driveline
what is the purpose of the retaining clips or wire on the bearing caps
to prevent them falling off and losing the needle bearings during removal or installation
when inspecting the universal joint what damage would you be looking for
pitting - end galling - brinelling - spalling
what may be caused by heavy work loads resulting in a breakdown of the bearing surface
spalling
what might be caused by lack of lubrication or incorrect working angle
end galling
what would having zero working angle or lack of lubrication cause
false brinelling
what would contaminated lubricant cause
pitting
how can you make sure the bearing end cap is fully seated after installation
tap with a soft face hammer then gently tighten bearing cup retaining screws - loosen screws and retorque to spec
why is it important to phase a driveline
to ensure the two universal joints on each driveline assembly are correctly aligned with each other
how can working angle be measured
with a bubble gauge or inclinometer
when using a inclinometer it must have
a degree scale that is accurate within 1/4 degree
when using a bubble gauge to measure phase make sure to
always face it in the same direction when reading it . turning it could introduce an error into your measurements
if the driveline is in phase but still out of balance what might be the problem
the slip joint was installed 180 degrees out of alignment
when measuring working angle and the driveline is sloped up this would be considered a
negative degree reading
when measuring working angle and the driveline is sloped down this would be considered a
positive degree reading
if a driveline shaft is level when measuring working angle it is considered a
zero degree working angle
when measuring working angle and both shafts have a positive or negative working angle then in order to find the total working angle of both shafts you must
subtract your readings - ( if one was 5 and the other was 3 then 5 - 3 = 2 degrees working angle )
when measuring the working angles and one side has a negative and the other has a positive then in order to find the total working angle you must
add or readings - ( if one was 2 degrees negative and the other was 1 degree positive then 2 + 1 = 3 the total would be 3 degrees
when calculating universal joint working angles you must only work with
one driveline at a time
what is a single plane working angle
when the universal joints will have a working angle in either the horizontal or vertical plane but not both
what is a compound working angle
when the driveline can be viewed from the top or the side and happens when the transmission and differential are not aligned on both the horizontal and vertical plane
universal joint angles must be equal to each other but they must also
be correct for the speed they will encounter
in order to determine if a vibration is coming from the engine or in the drivetrain you could preform a
stationary test
what would low speed vibration most likely be
wheel/tire or wheel bearing because they turn at about 1/4 speed as the driveshaft
at higher speeds a higher pitched sound and vibration will be in a driveshaft how is this confirmed
run the unit up through the vibration then let it coast down through the vibration if the noise and vibration are present during the increase and decrease in speed the problem is the driveshaft
