Drive Axle Assembly Fundamentals Flashcards
What 4 functions must the drive axle preform?
Carry weight of vehicle and load
Provide last gear reduction in basic powertrain
Change path of power 90 deg.
Account for wheel speed differences, while still delivering torque
Type size and # of drive axles is dependent on what?
Weight of the vehicle and load
Amount of traction required
final drive ratio
Gear ratio
of teeth on driven gear divided by # of teeth on drive gear
Startability
Is the percentage of grade at which a drivetrain system can start a loaded vehicle moving at idle
Overhung drive pinion
Is supported by 2 tapered roller bearings on yolk side of pinion gear
Straddle drive pinion
Has a short stub shaft that extends past the gear and can be supported by a roller or ball bearing. More common in high torque load situations
Bevel gear
Crown gear
Planetary diff high speed
Sun gear collar is shifted outward and locks with high speed clutch plate which is fixed to carrier. Sun and ring become locked creating direct drive
Planetary diff low speed
Sun gear collar is shifted inward and locks with low speed clutch plate, which is held stationary. The output member is the carrier and is apart of the differential case. This creates a reduction in the planetary
Differential torque
Diff assm. will always deliver the same amount of torque to each wheel
Power divider torque
When locked speed will be same for both outputs, but torque can be different depending on traction
Semi-floating axles
All operating forces are transmitted through the axle shafts.
Full floating axle
Only the rotational drive forces are carried through the axle
What are the 2 methods of diff lube?
Splash
Splash and pressure system
Driver controlled diff lock
Operator can lock the axle shaft on one side to the carrier housing
