401i Drive Axle Assembly Service (On-Road) Flashcards
When selecting particular gear oil, what must be considered?
The selection of gear oils is based on the ambient temperature that is expected in the area where a truck is operating.
When should a standpipe be installed in the rear axle housing?
When the drive axle assembly is installed at an angle of over 12°, or if the vehicle is expected to operate on steep grades for extended periods of time, a standpipe should be installed to ensure the pinion bearings receive and adequate amount of lubrication.
Housing joint leaks are generally contributed to faulty gaskets.
T/F
false; Typically, gaskets are not used between the housings. The housings are sealed with a RTV sealant. These joints can leak due to loose fasteners, imperfections in the surfaces or high torsional loading and stressing caused by high horsepower engines.
As a maintenance concern, on which shafts (2) should the end play be checked?
a) axle shafts
b) input shaft
c) output shaft
d) pinion shaft
b) input shaft
c) output shaft
Performing a plug swap usually involves:
a) draining all of the drive axle fluid and changing the plugs out.
b) removing the plug and holding the fluid in the drive axle with your finger while inspecting and the cleaning plug.
c) quickly exchanging the plug with another without draining all of the fluid.
d) swapping the fill plug with the drain plug during maintenance.
c) quickly exchanging the plug with another without draining all of the fluid.
When performing the road test, it was discovered that there was a noise that only occurred while cornering. The probable cause is:
a) low lubricant level.
b) worn differential thrust washers.
c) flat spots on the pinion and bevel gear (ring gear) teeth.
d) loose pinion bearings.
b) worn differential thrust washers.
The temperature at which the truck should be shut down and the cause of the excessive heat established and repaired is:
121°C (250°F).
When removing the carrier assembly from the drive axle housing, how would you lock the wheel lock assembly in the engaged position?
To lock the wheel lock assembly, a special bolt threaded into the air fitting port or applying 80–120 psi shop air to the shift cylinder should be used to lock the shift collar into place.
What check must be done before disassembling the carrier assembly?
backlash
Why must caution be used when removing the case half bolts?
If the differential is equipped with a no-spin traction enhancing device, the case halves will be spring loaded and longer bolts will have to be used to relieve the spring tension.
Which components should always be changed in sets?
a) bevel gear and pinion gear
b) right and left axle shafts
c) differential pinion gears and bevel gear
d) cross shaft and axle shafts
a) bevel gear and pinion gear.
The probable cause of a bent axle housing is:
a) vehicle overloading.
b) vehicle accident.
c) shock loading.
d) all of the above.
d) all of the above.
A fractured bevel (ring) gear tooth at the toe would be caused by:
a) insufficient lubrication.
b) improper lubrication.
c) shock impact loading.
d) all of the above.
c) shock impact loading.
Pinion bearing preload is established with:
a) shims between the bearing cage and the carrier housing.
b) threaded bearing adjusters.
c) different sized bearings.
d) shims between the pinion bearings.
d) shims between the pinion bearings.
When checking pinion bearing preload using a cord and a spring scale, record the reading required to start the assembly rolling.
T/F
false; When recording the spring scale reading, make sure that you record the torque while rolling rather than the torque required to start the assembly rolling.
