401i Drive Axle Assembly Service (On-Road) Flashcards Preview

HET4 190401 Clutch/ Driveline/ Transmission > 401i Drive Axle Assembly Service (On-Road) > Flashcards

Flashcards in 401i Drive Axle Assembly Service (On-Road) Deck (27):
1

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.

2

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.

3

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.

4

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

5

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.

6

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.

7

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).

8

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.

9

What check must be done before disassembling the carrier assembly?

backlash

10

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.

11

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.

12

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.

13

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.

14

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.

15

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.

16

The specific distance that the pinion and bevel gear are designed to run from each other is called:

nominal distance.

17

A positive etch number means the pinion must be positioned:
a) closer to the bevel gear centreline.
b) further from the bevel gear centreline.

b) further from the bevel gear centerline.

18

When changing the pinion position, a positive etch number always means that more shims, or a thicker spacer, is required.
T/F

false; Different methods are used to position the pinion in relation to the centreline of the bevel gear. Depending on the location of the shim or spacer determines whether the shim pack or spacer should be thicker or thinner.

19

On some carrier assemblies, a pinion depth setting gauge is used to determine the amount of shims required to accurately position the input pinion in the differential carrier housing.
T/F

true

20

Side bearing preload and backlash adjustment is done with:

threaded bearing adjusters.

21

When adjusting the backlash between the pinion and the bevel gear, if more backlash is required:

adjust the flanged half adjuster counter-clockwise and the plain half adjuster clockwise the same amount

22

If the tooth contact pattern shows excessive heel:
a) move the pinion in and re-adjust ring gear for proper backlash.
b) move the pinion out and re-adjust the ring gear for proper backlash.
c) move the ring gear toward the pinion.
d) move the ring gear away from the pinion.

c) move the ring gear toward the pinion.

23

On a carrier assembly, if a thrust screw is used, mark the spot with the most
________________________ the thrust screw side of the bevel gear.
a) back face runout toward
b) back face runout away
c) radial towards
d) radial away from

back face runout toward

24

Correct endplay on the input shaft of the inter-axle differential assembly is established with:
a) shims between the bearing cage and the inter-axle differential housing.
b) threaded bearing adjusters.
c) different sized bearings.
d) shims between the pinion bearings.

a) shims between the bearing cage and the inter-axle differential housing.

25

To adjust the inter-axle differential shift collar, apply air pressure to the cylinder to get full travel and then limit the maximum travel with the adjusting bolt.
T/F

true

26

If the carrier assembly was removed because of a failure and the gear oil was contaminated, what extra service procedure must also be done?

If the differential carrier assembly was removed because of a failure and the gear oil was contaminated, the wheel end assemblies must be removed, hubs cleaned and the bearings inspected.

27

Why must the oil level be rechecked after the drive axle assembly is driven for a short period of time and then shut down for five minutes?

This allows time for the gear oil to circulate throughout the system and then drain down into each oil reservoir.