transfercase and auxillary drives

Question 1

when would a transfer case be required

Answer 1

when operating in soft soil or off road and more traction is needed without adding more rear driving axles

Question 2

why do most transfer cases use helical gearing

Answer 2

to handle the tremendous torque loads placed on them

Question 3

how is the helical thrust load on a shaft offset

Answer 3

with tapered roller bearings

Question 4

how many inputs and outputs do transfer cases have

Answer 4

one input and two output

Question 5

how are most transfer cases lubricated

Answer 5

splash type with oil in a reservoir and can also have a positive displacement oil pump for areas where there is a speed difference such as PTO and front axle declutch

Question 6

how is the internal oil pump driven

Answer 6

off the end of one of the shafts in the transfer case

Question 7

what is the purpose of the front declutch

Answer 7

to allow the operator to disengage the torque to the front drive axle when ground conditions are good ( highway - dry even ground )

Question 8

how is the front axle engaged

Answer 8

with a electric over air or air shift collar on a set of splines

Question 9

on a short wheel based vehicle what drivetrain equipment is used to drive the front driving axle

Answer 9

a special inter-axle differential assembly

Question 10

what is the function of the transfer case

Answer 10

the transfer case receives torque from the main auxiliary transmission . it then sends that torque on to the rear driving axles and forward to the front driving axle

Question 11

what is the mechanism that gives the operator the ability to disengage the torque to the front drive axle

Answer 11

front axle declutch

Question 12

what are the typical gear ranges for High and low with a transfer case with more than one gear range

Answer 12

high range is usually direct drive 1:1 while low range is usually 2:1 or 2.5:1 reduction

Question 13

what device does a full time transfer case use to prevent driveline windup

Answer 13

a planetary gear set

Question 14

can a transfer case mounted power take off receive more torque than the engine can develop

Answer 14

yes . because the power take off is mounted after the transmission it is able to receive varying amounts of torque . this is dependant on the gear selected in the main transmission

Question 15

what could cause oil to be lost out the breather

Answer 15

if either the range shift cylinder, front axle declutch cylinder or power takeoff shift cylinder O-rings are leaking . the housing is put under excessive pressure and the rapid air venting can cause oil to be pulled out

Question 16

what could cause excessive vibration in the transfer case

Answer 16

operating on good roads with the front axle declutch engaged . excessive driveline angles . excessive transfer case bearing endplay

Question 17

one of the vital concerns with transfer case assembly is

Answer 17

bearing endplay

Question 18

which types of auxiliary drive systems are always driving any time the engine is turning

Answer 18

front engine mounted and rear engine mounted

Question 19

what must the operator do before engaging the power takeoff

Answer 19

stop the transmission counter shaft from turning

Question 20

on the air actuated power takeoff system what is the air routed through before going to the air valve

Answer 20

the pressure protection valve

Question 21

the indicator light for the power takeoff system is activated by what

Answer 21

a normally closed or normally open engagement switch mounted on the shift cover

Question 22

what two functions do the gaskets between the power takeoff and the transmission provide

Answer 22

acts as a seal to prevent lubrication from leaking between the two components . provide a way of setting the proper backlash between the PTO input gear as well as between the adaptor housing gear and the PTO input gear

Question 23

PTO gear backlash must be measured between

Answer 23

the PTO input gear and the transmission drive gear

Question 24

when installing an adaptor housing what backlash must be adjusted

Answer 24

proper backlash must be established between the transmission drive gear and the adaptor housing as well as between the adaptor housing gear and the PTO input gear

Question 25

if the power takeoff is installed with insufficient backlash what will the complaint be

Answer 25

gear whine

Question 26

when reinstalling a repaired power takeoff is it acceptable to install without measuring backlash if the same number and thickness of gaskets are used

Answer 26

false . backlash must always be measured when installing

Question 27

if the transfer case is a two speed or a single speed with a ratio other than direct drive where will the speedometer sensor be attached

Answer 27

to the rear output shaft of the transfer case .

Question 28

why is the speed sensor mounted to the rear output shaft of the transfer case if it is a two or single speed with a ratio other than direct drive

Answer 28

this ensures that the vehicle speedometer and the engine and transmission ECU are always reading the correct vehicle speed

Question 29

what is the proportion of torque delivered to the front and rear axels when utilizing a planetary gear set

Answer 29

front 30% and rear 70 %

Question 30

when checking the oil level in the transfer case

Answer 30

the oil must be level with the bottom of the filler plug opening

Question 31

what is one quick method of determining if the transfer case is damaged

Answer 31

by preforming a plug swap and inspecting the magnetic plug