Drive axle assembly service

Question 1

when selecting particular gear oil, what must be considered

Answer 1

the selection of gear oil is based on the ambient temperature that is expected In that area where the truck is operating

Question 2

when should a standpipe be installed in the rear axle housing

Answer 2

when the drive axle is installed at an angle of over 12 degrees . or if the vehicle is operating at steep angles for extended periods of time

Question 3

what are housing leaks generally contributed to

Answer 3

loose fasteners - imperfections in the surfaces - high torsional loads and stressing caused by high horsepower engines

Question 4

as a maintenance concern which shafts should end play be checked

Answer 4

input shaft and output shaft

Question 5

preforming a plug swap usually involves

Answer 5

quickly changing the plug with another plug without draining all the oil

Question 6

what might a noise only during cornering be

Answer 6

worn differential thrust washers

Question 7

what temperature should the truck be shut down and the cause of an excessive heat be established and repaired

Answer 7

121 C or 250 F

Question 8

when removing the carrier assembly from the drive axle housing, how would you lock the wheel lock assembly in the engaged position

Answer 8

with a special bolt threaded into the air fitting port or applying 80 psi - 120 psi to the shift cylinder to lock the shift collar in place

Question 9

what check must be done before disassembling the carrier assembly

Answer 9

backlash

Question 10

why must caution be used when removing the case half bolts

Answer 10

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 relive spring tension

Question 11

which component should always be changed in sets

Answer 11

bevel gear and pinion gear

Question 12

the probable cause of a bent axle housing would be

Answer 12

vehicle overloading - vehicle accident - shock loading

Question 13

what might cause a fractured bevel gear tooth at the toe

Answer 13

shock impact loading

Question 14

how is pinion bearing pre-load established

Answer 14

shims between the pinion bearings

Question 15

how is pinion bearing pre-load checked using a cord and spring scale

Answer 15

record the torque while rolling rather than the torque required to start the assembly rolling

Question 16

what is the specific distance that a pinion and bevel gear are set to run from each other called

Answer 16

nominal distance

Question 17

what would a positive etch number mean on a pinion

Answer 17

further from the bevel gear center line

Question 18

what determines the spacing required when changing the pinion position

Answer 18

depending on the location of the shim or spacer determines whether the shim pack or spacer should be thicker or thinner

Question 19

what can also be used on some carrier assemblies to determine the amount of shims required to accurately position the input pinion in the differential carrier housing

Answer 19

a pinion depth setting gauge

Question 20

side bearing pre-load and backlash is done with

Answer 20

threaded bearing adjusters

Question 21

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

Answer 21

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

Question 22

if tooth contact pattern shows excessive heel

Answer 22

move the ring gear toward the pinion

Question 23

on a carrier assembly if a thrust screw is used you should mark the spot with the most ?

Answer 23

back faced runout toward the thrust screw side of the bevel gear

Question 24

how is the correct end play established on the input shaft of the inter-axle differential assembly

Answer 24

shims between the bearing cage and the inter-axle differential housing

Question 25

how is the inter-axle shift collar adjusted

Answer 25

apply air pressure to the cylinder to get full travel and then limit the maximum travel with the adjusting bolt

Question 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

Answer 26

the wheel end assemblies must be removed, hubs cleaned and the bearings inspected

Question 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

Answer 27

this allows the oil to circulate through the system and then drain down into each oil reservoir

Question 28

why is the use of some synthetic gear oil restricted for drive axle use

Answer 28

because some of the seals are not compatible with the gear oil and will leak

Question 29

when checking the oil level in a drive axle it should be

Answer 29

level with the filler opening

Question 30

to ensure that the wheel ends receive the proper amount of oil and to ensure the level in the differential is adequate you should

Answer 30

jack up each end of the axle and the oil be allowed to fill each wheel assembly

Question 31

how is heat generated in the axle housing dissipated

Answer 31

through the housing to the surrounding air

Question 32

if the axle housing is covered in mud and dirt what problem might this cause

Answer 32

overheating issue